650 kHz /1.3 MHz Step-Up PWM DC-to-DC Switching Converters / ADP1612

650 kHz /1.3 MHz Step-Up PWM DC-to-DC Switching Converters / ADP1612

Data Sheet

FEATURES

Current limit

1.4 A for the ADP1612

2.0 A for the ADP 1613

Minimum input voltage

1.8 V for the ADP1612

2.5 V for the ADP1613

Pin-selectable 650 kHz or 1.3 MHz PWM frequency

Adjustable output voltage up to 20 V

Adjustable soft start

Undervoltage lockout

Thermal shutdown

8-lead MSOP

Supported by ADIsimPower™ design tool

ADIsimPower downloadable design tools for boost, coupled-

SEPIC, and SEPIC Cuk configurations

650 kHz /1.3 MHz Step-Up

PWM DC-to-DC Switching Converters

ADP1612

/

ADP1613

V

IN

C

IN

TYPICAL APPLICATION CIRCUIT

L1

OFF

650kHz

(DEFAULT)

1.3MHz

C

SS

ON

6

3

7

8

VIN

ADP1612/

ADP1613

SW

EN

FREQ

SS

GND

4

FB

COMP

5

2

1

D1

R

COMP

C

COMP

Figure 1. Step-Up Regulator Configuration

R1

R2

V

OUT

C

OUT

APPLICATIONS

TFT LCD bias supplies

Portable applications

Industrial/instrumentation equipment

GENERAL DESCRIPTION

The ADP1612/ADP1613 are step-up dc-to-dc switching converters with an integrated power switch capable of providing an output voltage as high as 20 V. With a package height of less than 1.1 mm, the ADP1612/ADP1613 are optimal for spaceconstrained applications such as portable devices or thin film transistor (TFT) liquid crystal displays (LCDs).

The ADP1612/ADP1613 operate in current mode pulse-width modulation (PWM) with up to 94% efficiency. Adjustable soft start prevents inrush currents when the part is enabled.

The pin-selectable switching frequency and PWM current-mode architecture allow for excellent transient response, easy noise filtering, and the use of small, cost-saving external inductors and capacitors. Other key features include undervoltage lockout

(UVLO), thermal shutdown (TSD), and logic controlled enable.

The ADP1612/ADP1613 are available in the lead-free

8-lead MSOP.

100

90

80

70

60

V

IN

= 5V f

SW

= 1.3MHz

T

A

= 25°C

50

40

ADP1612, V

OUT

= 12V

ADP1612, V

OUT

= 15V

ADP1613, V

OUT

= 12V

ADP1613, V

OUT

= 15V

30

1 10 100 1k

LOAD CURRENT (mA)

Figure 2. ADP1612/ADP1613 Efficiency for Various Output Voltages

Rev. D

Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices.

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Tel: 781.329.4700 www.analog.com

Fax: 781.461.3113 ©2009–2012 Analog Devices, Inc. All rights reserved.

ADP1612/ADP1613

TABLE OF CONTENTS

Features .............................................................................................. 1

Applications ....................................................................................... 1

Typical Application Circuit ............................................................. 1

General Description ......................................................................... 1

Revision History ............................................................................... 2

Specifications ..................................................................................... 3

Absolute Maximum Ratings ............................................................ 4

Thermal Resistance ...................................................................... 4

Boundary Condition .................................................................... 4

ESD Caution .................................................................................. 4

Pin Configuration and Function Descriptions ............................. 5

Typical Performance Characteristics ............................................. 6

Theory of Operation ...................................................................... 11

Current-Mode PWM Operation .............................................. 11

Frequency Selection ................................................................... 11

Soft Start ...................................................................................... 11

Thermal Shutdown (TSD) ......................................................... 12

UnderVoltage Lockout (UVLO) ............................................... 12

REVISION HISTORY

11/12—Rev. C to Rev. D

Changes to Choosing the Input and Output Capacitors Section and Loop Compensation Section .................................................. 14

7/12—Rev. B to Rev. C

Changes to Features Section............................................................. 1

Added ADIsimPower Design Tool Section .................................. 13

Changes to Ordering Guide ........................................................... 25

4/11—Rev. A to Rev. B

Changes to Features Section............................................................ 1

Changes to Reference Feedback Voltage Parameter .................... 3

Changes to Ordering Guide .......................................................... 25

Data Sheet

Enable/Shutdown Control ........................................................ 12

Applications Information .............................................................. 13

ADIsimPower Design Tool ....................................................... 13

Setting the Output Voltage ........................................................ 13

Inductor Selection ...................................................................... 13

Choosing the Input and Output Capacitors ........................... 14

Diode Selection ........................................................................... 14

Loop Compensation .................................................................. 14

Soft Start Capacitor .................................................................... 15

Typical Application Circuits ......................................................... 16

Step-Up Regulator ...................................................................... 16

Step-Up Regulator Circuit Examples ....................................... 16

SEPIC Converter ........................................................................ 22

TFT LCD Bias Supply ................................................................ 22

PCB Layout Guidelines .................................................................. 24

Outline Dimensions ....................................................................... 25

Ordering Guide .......................................................................... 25

9/09—Rev. 0 to Rev. A

Changes to Figure 45 ...................................................................... 17

Changes to Figure 48 and Figure 51 ............................................ 18

Changes to Figure 54 and Figure 57 ............................................ 19

Changes to Figure 60 and Figure 63 ............................................ 20

Changes to Figure 66 and Figure 69 ............................................ 21

Changes to Figure 72 ...................................................................... 22

Changes to Ordering Guide .......................................................... 25

4/09—Revision 0: Initial Version

Rev. D | Page 2 of 28

Data Sheet ADP1612/ADP1613

SPECIFICATIONS

V

IN

= 3.6 V, unless otherwise noted. Minimum and maximum values are guaranteed for T

J

= −40°C to +125°C. Typical values specified are at T

J

= 25°C. All limits at temperature extremes are guaranteed by correlation and characterization using standard statistical quality control (SQC), unless otherwise noted.

Table 1.

Parameter

SUPPLY

Input Voltage

Quiescent Current

Nonswitching State

Shutdown

Switching State 1

Enable Pin Bias Current

OUTPUT

Output Voltage

Load Regulation

I

Symbol Conditions

V

I

Q

IN

EN

I

QSHDN

I

QSW

ADP1612

ADP1613

V

FB

= 1.5 V, FREQ = V

IN

V

FB

= 1.5 V, FREQ = GND

V

EN

= 0 V

FREQ = V

IN

, no load

FREQ = GND, no load

V

EN

= 3.6 V

Min Typ Max Unit

1.8

2.5

2.2

3.3

5.5

5.5

0.01 2

4 5.8

4

7

V

V

900 1350 µA

700 1300 µA

µA mA mA

µA

REFERENCE

Feedback Voltage

Line Regulation

ERROR AMPLIFIER

Transconductance

Voltage Gain

FB Pin Bias Current

SWITCH

SW On Resistance

SW Leakage Current

Peak Current Limit

2

OSCILLATOR

Oscillator Frequency

Maximum Duty Cycle

FREQ Pin Current

V

V

FB

G

A

R

DSON

I

CL

OUT

MEA

V

EN/FREQ LOGIC THRESHOLD

Input Voltage Low

Input Voltage High

SOFT START

SS Charging Current

SS Voltage

UNDERVOLTAGE LOCKOUT (UVLO)

Undervoltage Lockout Threshold

V

IL

V

IH

I

SS

V

SS f

SW

D

MAX

I

FREQ

I

LOAD

= 10 mA to 150 mA, V

IN

= 3.3 V, V

OUT

= 12 V

ADP1612, V

IN

= 1.8 V to 5.5 V; ADP1613, V

IN

= 2.5 V to 5.5 V

ΔI = 4 µA

V

FB

= 1.3 V

I

SW

= 1.0 A

V

SW

= 20 V

ADP1612, duty cycle = 70%

ADP1613, duty cycle = 70%

FREQ = GND

FREQ = V

IN

V

SS

= 0 V

V

FB

= 1.3 V

COMP = open, V

FREQ = 3.6 V

FB

= 1 V, FREQ = V

ADP1612, V

IN

rising

ADP1612, V

IN

falling

IN

ADP1612, V

IN

= 1.8 V to 5.5 V; ADP1613, V

IN

= 2.5 V to 5.5 V

V

IN

1.215

THERMAL SHUTDOWN

Thermal Shutdown Threshold

ADP1613, V

ADP1613, V

IN

IN

rising

falling

Thermal Shutdown Hysteresis

1

2

This parameter specifies the average current while switching internally and with SW (Pin 5) floating.

Current limit is a function of duty cycle. See the Typical Performance Characteristics section for typical values over operating ranges.

0.9

1.3

500

1.1

88

1.6

3.4

0.1

2.0

20

1.235 1.255

0.07

80

60

1

130 300

0.01 10

1.4 1.9

650

1.3

90

5

5

1.2

1.70

1.62

2.25

2.16

150

20

0.24

50

2.5

720

1.4

8

0.3

6.2

V mV/mA

V

%/V

µA/V dB nA mΩ

µA

A

A kHz

MHz

%

μA

V

V

µA

V

V

V

V

V

°C

°C

Rev. D | Page 3 of 28

ADP1612/ADP1613

ABSOLUTE MAXIMUM RATINGS

Table 2.

Parameter Rating

VIN, EN, FB to GND

FREQ to GND

COMP to GND

SS to GND

−0.3 V to +6 V

−0.3 V to V

IN

+ 0.3 V

1.0 V to 1.6 V

−0.3 V to +1.3 V

SW to GND 21 V

Operating Junction Temperature Range −40°C to +125°C

Storage Temperature Range

Soldering Conditions

−65°C to +150°C

JEDEC J-STD-020

ESD (Electrostatic Discharge)

Human Body Model ±5 kV

Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

Absolute maximum ratings apply individually only, not in combination.

Data Sheet

THERMAL RESISTANCE

Junction-to-ambient thermal resistance (θ

JA

) of the package is specified for the worst-case conditions, that is, a device soldered in a circuit board for surface-mount packages. The junction-toambient thermal resistance is highly dependent on the application and board layout. In applications where high maximum power dissipation exists, attention to thermal board design is required.

The value of θ

JA

may vary, depending on PCB material, layout, and environmental conditions.

Table 3.

Package Type

8-Lead MSOP

2-Layer Board 1

4-Layer Board 1

θ

JA

206.9

162.2

1 Thermal numbers per JEDEC standard JESD 51-7.

BOUNDARY CONDITION

θ

JC

44.22

44.22

Unit

°C/W

°C/W

Modeled under natural convection cooling at 25°C ambient temperature, JESD 51-7, and 1 W power input with 2- and

4-layer boards.

ESD CAUTION

Rev. D | Page 4 of 28

Data Sheet

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

ADP1612/ADP1613

COMP

1

FB

2

EN

3

GND

4

ADP1612/

ADP1613

TOP VIEW

(Not to Scale)

8

7

6

5

SS

FREQ

VIN

SW

Figure 3. Pin Configuration

1

2

3

4

5

Table 4. Pin Function Descriptions

Pin No. Mnemonic Description

6

7

8

COMP

FB

EN

GND

SW

VIN

FREQ

SS

Compensation Input. Connect a series resistor-capacitor network from COMP to GND to compensate the regulator.

Output Voltage Feedback Input. Connect a resistive voltage divider from the output voltage to FB to set the regulator output voltage.

Enable Input. Drive EN low to shut down the regulator; drive EN high to turn on the regulator.

Ground.

Switching Output. Connect the power inductor from the input voltage to SW and connect the external rectifier from SW to the output voltage to complete the step-up converter.

Main Power Supply Input. VIN powers the ADP1612/ADP1613 internal circuitry. Connect VIN to the input source voltage. Bypass VIN to GND with a 10 µF or greater capacitor as close to the ADP1612/ADP1613 as possible.

Frequency Setting Input. FREQ controls the switching frequency. Connect FREQ to GND to program the oscillator to 650 kHz, or connect FREQ to VIN to program it to 1.3 MHz. If FREQ is left floating, the part defaults to 650 kHz.

Soft Start Timing Capacitor Input. A capacitor connected from SS to GND brings up the output slowly at powerup and reduces inrush current.

Rev. D | Page 5 of 28

ADP1612/ADP1613

TYPICAL PERFORMANCE CHARACTERISTICS

V

EN

= V

IN

and T

A

= 25°C, unless otherwise noted.

100

90 f

V

IN

= 3.3V

SW

= 650kHz

T

A

= 25°C

80

ADP1612

70

60

50

40

V

OUT

= 5V

V

OUT

= 12V

V

OUT

= 15V

30

1 10 100 1k

LOAD CURRENT (mA)

Figure 4. ADP1612 Efficiency vs. Load Current, V

IN

= 3.3 V, f

SW

= 650 kHz

Data Sheet

100

90

V

IN

= 5V f

SW

= 1.3MHz

T

A

= 25°C

80

70

ADP1612

60

50

40

V

OUT

= 12V

V

OUT

= 15V

30

1 10 100 1k

LOAD CURRENT (mA)

Figure 7. ADP1612 Efficiency vs. Load Current, V

IN

= 5 V, f

SW

= 1.3 MHz

100

90 f

V

IN

= 3.3V

SW

= 1.3MHz

T

A

= 25°C

80

70

ADP1612

60

50

40

V

OUT

= 5V

V

OUT

= 12V

V

OUT

= 15V

30

1 10 100 1k

LOAD CURRENT (mA)

Figure 5. ADP1612 Efficiency vs. Load Current, V

IN

= 3.3 V, f

SW

= 1.3 MHz

100

90

V

IN

= 5V f

SW

= 650kHz

T

A

= 25°C

80

ADP1612

70

60

50

40

V

OUT

= 12V

V

OUT

= 15V

30

1 10 100 1k

LOAD CURRENT (mA)

Figure 6. ADP1612 Efficiency vs. Load Current, V

IN

= 5 V, f

SW

= 650 kHz

100

90

V

IN

= 5V f

SW

= 650kHz

T

A

= 25°C

80

70

ADP1613

60

50

40

V

OUT

= 12V

V

OUT

= 15V

V

OUT

= 20V

30

1 10 100 1k

LOAD CURRENT (mA)

Figure 8. ADP1613 Efficiency vs. Load Current, V

IN

= 5 V, f

SW

= 650 kHz

100

90

V

IN

= 5V f

SW

= 1.3MHz

T

A

= 25°C

80

ADP1613

70

60

50

40

V

OUT

= 12V

V

OUT

= 15V

V

OUT

= 20V

30

1 10 100 1k

LOAD CURRENT (mA)

Figure 9. ADP1613 Efficiency vs. Load Current, V

IN

= 5 V, f

SW

= 1.3 MHz

Rev. D | Page 6 of 28

Data Sheet

2.4

ADP1612

2.2

2.0

T

A

= +25°C

1.8

1.6

T

A

= –40°C

1.4

T

A

= +85°C

1.2

1.8

2.3

2.8

3.3

3.8

4.3

4.8

INPUT VOLTAGE (V)

Figure 10. ADP1612 Switch Current Limit vs. Input Voltage, V

OUT

= 5 V

2.0

ADP1612

1.8

1.6

T

A

= +25°C

1.4

T

A

= –40°C

1.2

T

A

= +85°C

1.0

1.8

2.3

2.8

3.3

3.8

4.3

4.8

5.3

INPUT VOLTAGE (V)

Figure 11. ADP1612 Switch Current Limit vs. Input Voltage, V

OUT

= 8 V

1.6

ADP1612

1.4

T

A

= –40°C

T

A

= +25°C

1.2

T

A

= +85°C

1.0

0.8

1.8

2.3

2.8

3.3

3.8

4.3

4.8

5.3

INPUT VOLTAGE (V)

Figure 12. ADP1612 Switch Current Limit vs. Input Voltage, V

OUT

= 15 V

ADP1612/ADP1613

3.4

ADP1613

3.2

3.0

2.8

2.6

2.4

2.2

T

A

= +85°C

T

A

= +25°C

T

A

= –40°C

2.0

2.5

3.0

3.5

4.0

4.5

INPUT VOLTAGE (V)

Figure 13. ADP1613 Switch Current Limit vs. Input Voltage, V

OUT

= 5 V

2.6

ADP1613

2.4

T

A

= +25°C

2.2

T

A

= –40°C

2.0

T

A

= +85°C

1.8

2.5

3.0

3.5

4.0

4.5

5.0

5.5

INPUT VOLTAGE (V)

Figure 14. ADP1613 Switch Current Limit vs. Input Voltage, V

OUT

= 8 V

2.2

2.0

2.6

ADP1613

2.4

T

A

= –40°C

1.8

T

A

= +25°C

1.6

T

A

= +85°C

1.4

2.5

3.0

3.5

4.0

4.5

INPUT VOLTAGE (V)

5.0

5.5

Figure 15. ADP1613 Switch Current Limit vs. Input Voltage, V

OUT

= 15 V

Rev. D | Page 7 of 28

ADP1612/ADP1613

800

ADP1612/ADP1613

550

500

450

750

700

650

600

T

A

= +125°C

T

A

= +25°C

T

A

= –40°C

400

1.8

2.3

2.8

3.3

3.8

4.3

4.8

5.3

INPUT VOLTAGE (V)

Figure 16. ADP1612/ADP1613 Quiescent Current vs. Input Voltage,

Nonswitching, f

SW

= 650 kHz

800

ADP1612/ADP1613

750

700

T

A

= +125°C

650

600

550

T

A

= +25°C

T

A

= –40°C

500

1.8

2.3

2.8

3.3

3.8

4.3

4.8

5.3

INPUT VOLTAGE (V)

Figure 17. ADP1612/ADP1613 Quiescent Current vs. Input Voltage,

Nonswitching, f

SW

= 1.3 MHz

3.5

ADP1612/ADP1613

3.0

T

A

= +25°C

2.5

T

A

= +125°C

2.0

T

A

= –40°C

1.5

1.0

1.8

2.3

2.8

3.3

3.8

4.3

4.8

5.3

INPUT VOLTAGE (V)

Figure 18. ADP1612/ADP1613 Quiescent Current vs. Input Voltage,

Switching, f

SW

= 650 kHz

Rev. D | Page 8 of 28

Data Sheet

6

ADP1612/ADP1613

5

T

A

= +25°C

4

T

A

= +125°C

T

A

= –40°C

3

2

1

1.8

2.3

2.8

3.3

3.8

4.3

4.8

5.3

INPUT VOLTAGE (V)

Figure 19. ADP1612/ADP1613 Quiescent Current vs. Input Voltage,

Switching, f

SW

= 1.3 MHz

190

170

150

130

110

250

230

210

I

SW

= 1A

T

A

= +30°C

T

A

= +85°C

ADP1612/ADP1613

90

T

A

= –40°C

70

1.8

2.3

2.8

3.3

3.8

INPUT VOLTAGE (V)

4.3

4.8

5.3

Figure 20. ADP1612/ADP1613 On Resistance vs. Input Voltage

190

170

150

130

250

230

ADP1612/ADP1613

V

IN

= 1.8V

210

V

IN

= 2.5V

I

SW

= 1A

110

V

IN

= 3.6V

90

V

IN

= 5.5V

70

–40 –15 10 35

TEMPERATURE (°C)

60 85

Figure 21. ADP1612/ADP1613 On Resistance vs. Temperature

Data Sheet

660

ADP1612/ADP1613

650

640

630

620

T

A

= +125°C

610

600

T

A

= +25°C

590

T

A

= –40°C

580

1.8

2.3

2.8

3.3

3.8

4.3

4.8

5.3

INPUT VOLTAGE (V)

Figure 22. ADP1612/ADP1613 Frequency vs. Input Voltage, f

SW

= 650 kHz

1.32

1.30

ADP1612/ADP1613

1.28

1.26

1.24

1.22

1.20

T

A

= +25°C

T

A

= –40°C

1.18

T

A

= +125°C

1.16

1.14

1.8

2.3

2.8

3.3

3.8

4.3

4.8

5.3

INPUT VOLTAGE (V)

Figure 23. ADP1612/ADP1613 Frequency vs. Input Voltage, f

SW

= 1.3 MHz

5

4

7

ADP1612/ADP1613

6

T

A

= +125°C

3

2

T

A

= +25°C

1

T

A

= –40°C

0

0 0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

EN PIN VOLTAGE (V)

Figure 24. ADP1612/ADP1613 EN Pin Current vs. EN Pin Voltage

ADP1612/ADP1613

4.8

4.7

5.1

ADP1612/ADP1613

5.0

4.9

4.6

V

IN

= 5.5V

V

IN

= 3.6V

V

IN

= 1.8V

4.5

–40 –10 20 50

TEMPERATURE (°C)

80 110

Figure 25. ADP1612/ADP1613 SS Pin Current vs. Temperature

92.8

ADP1612/ADP1613

92.6

92.4

T

A

= +125°C

92.2

92.0

91.8

91.6

91.4

T

A

= +25°C

T

A

= –40°C

91.2

1.8

2.3

2.8

3.3

3.8

4.3

4.8

5.3

INPUT VOLTAGE (V)

Figure 26. ADP1612/ADP1613 Maximum Duty Cycle vs. Input Voltage, f

SW

= 650 kHz

93.4

93.2

ADP1612/ADP1613

T

A

= +25°C

93.0

T

A

= +125°C

92.8

92.6

92.4

92.2

T

A

= –40°C

92.0

91.8

91.6

1.8

2.3

2.8

3.3

3.8

4.3

4.8

5.3

INPUT VOLTAGE (V)

Figure 27. ADP1612/ADP1613 Maximum Duty Cycle vs. Input Voltage, f

SW

= 1.3 MHz

Rev. D | Page 9 of 28

ADP1612/ADP1613

T

OUTPUT VOLTAGE (5V/DIV)

INDUCTOR CURRENT

(200mA/DIV)

V

IN

= 5V

V

OUT

= 12V

I

LOAD

= 20mA

L = 6.8µH f

SW

= 1.3MHz

C

OUT

= 10µF

SWITCH VOLTAGE (10V/DIV)

TIME (400ns/DIV)

Figure 28. ADP1612/ADP1613 Switching Waveform in Discontinuous

Conduction Mode

T

OUTPUT VOLTAGE (5V/DIV)

INDUCTOR CURRENT

(500mA/DIV)

I

V

IN

= 5V

V

OUT

LOAD

= 12V

= 200mA

L = 6.8µH f

SW

C

= 1.3MHz

OUT

= 10µF

SWITCH VOLTAGE (10V/DIV)

TIME (400ns/DIV)

Figure 29. ADP1612/ADP1613 Switching Waveform in Continuous

Conduction Mode

T

OUTPUT VOLTAGE (5V/DIV)

V

IN

= 5V

V

OUT

= 12V

I

LOAD

= 250mA

L = 6.8µH f

SW

= 1.3MHz

SWITCH VOLTAGE (10V/DIV)

INDUCTOR CURRENT (2A/DIV)

EN PIN VOLTAGE (5V/DIV)

TIME (20ms/DIV)

Figure 30. ADP1612/ADP1613 Start-Up from V

IN

, C

SS

=33 nF

Data Sheet

T

OUTPUT VOLTAGE (5V/DIV)

SWITCH VOLTAGE (10V/DIV)

V

IN

= 5V

V

OUT

= 12V

I

LOAD

= 250mA

L = 6.8µH f

SW

= 1.3MHz

INDUCTOR CURRENT (2A/DIV)

EN PIN VOLTAGE (5V/DIV)

TIME (20ms/DIV)

Figure 31. ADP1612/ADP1613 Start-Up from V

IN

, C

SS

=100 nF

T

OUTPUT VOLTAGE (5V/DIV)

SWITCH VOLTAGE (10V/DIV)

V

IN

= 5V

V

OUT

= 12V

I

LOAD

= 250mA

L = 6.8µH f

SW

= 1.3MHz

INDUCTOR CURRENT (500mA/DIV)

EN PIN VOLTAGE (5V/DIV)

TIME (400µs/DIV)

Figure 32. ADP1612/ADP1613 Start-Up from Shutdown, C

SS

= 33 nF

T

OUTPUT VOLTAGE (5V/DIV)

SWITCH VOLTAGE (10V/DIV)

V

IN

= 5V

V

OUT

= 12V

I

LOAD

= 250mA

L = 6.8µH f

SW

= 1.3MHz

INDUCTOR CURRENT (500mA/DIV)

EN PIN VOLTAGE (5V/DIV)

TIME (400µs/DIV)

Figure 33. ADP1612/ADP1613 Start-Up from Shutdown, C

SS

= 100 nF

Rev. D | Page 10 of 28

Data Sheet

THEORY OF OPERATION

V

IN

L1

ADP1612/ADP1613

C

IN

VIN

6

>1.6V

<0.3V

7

FREQ

5

SW

D1

V

IN

D

COMPARATOR

+

+

A

CURRENT

SENSING

C

OUT

V

OUT

V

OUT

PWM

COMPARATOR D

REF

R1

FB

2

ERROR

AMPLIFIER

OSCILLATOR

R2

R

COMP

C

COMP

COMP

1 S

R

5µA

V

BG

V

SS

5µA

UVLO

COMPARATOR

V

IN

UVLO

REF

TSD

COMPARATOR

T

SENSE

Q

DRIVER

N1

SS

8

T

REF

RESET

BG BAND GAP

SOFT

START

C

SS

AGND

1.1MΩ

ADP1612/AD1613

AGND

EN

3

>1.6V

<0.3V

4

GND

Figure 34. Block Diagram with Step-Up Regulator Application Circuit

The ADP1612/ADP1613 current-mode step-up switching converters boost a 1.8 V to 5.5 V input voltage to an output voltage as high as 20 V. The internal switch allows a high output current, and the high 650 kHz/1.3 MHz switching frequency allows for the use of tiny external components.

The switch current is monitored on a pulse-by-pulse basis to limit it to 1.4 A typical (ADP1612) or 2.0 A typical (ADP1613).

CURRENT-MODE PWM OPERATION

The ADP1612/ADP1613 utilize a current-mode PWM control scheme to regulate the output voltage over all load conditions.

The output voltage is monitored at FB through a resistive voltage divider. The voltage at FB is compared to the internal 1.235 V reference by the internal transconductance error amplifier to create an error voltage at COMP. The switch current is internally measured and added to the stabilizing ramp. The resulting sum is compared to the error voltage at COMP to control the PWM modulator. This current-mode regulation system allows fast transient response, while maintaining a stable output voltage.

By selecting the proper resistor-capacitor network from COMP to GND, the regulator response is optimized for a wide range of input voltages, output voltages, and load conditions.

FREQUENCY SELECTION

The frequency of the ADP1612/ADP1613 is pin-selectable to operate at either 650 kHz to optimize the regulator for high efficiency or at 1.3 MHz for use with small external components.

If FREQ is left floating, the part defaults to 650 kHz. Connect

FREQ to GND for 650 kHz operation or connect FREQ to VIN for 1.3 MHz operation. When connected to VIN for 1.3 MHz operation, an additional 5 μA, typical, of quiescent current is active. This current is turned off when the part is shutdown.

SOFT START

To prevent input inrush current to the converter when the part is enabled, connect a capacitor from SS to GND to set the soft start period. Once the ADP1612/ADP1613 are turned on, SS sources

5 µA, typical, to the soft start capacitor (C

SS

) until it reaches

1.2 V at startup. As the soft start capacitor charges, it limits the peak current allowed by the part. By slowly charging the soft start capacitor, the input current ramps slowly to prevent it from overshooting excessively at startup. When the ADP1612/

ADP1613 are in shutdown mode (EN ≤ 0.3 V), a thermal shutdown event occurs, or the input voltage is below the falling undervoltage lockout voltage, SS is internally shorted to GND to discharge the soft start capacitor.

Rev. D | Page 11 of 28

ADP1612/ADP1613

THERMAL SHUTDOWN (TSD)

The ADP1612/ADP1613 include TSD protection. If the die temperature exceeds 150°C (typical), TSD turns off the NMOS power device, significantly reducing power dissipation in the device and preventing output voltage regulation. The NMOS power device remains off until the die temperature reduces to

130°C (typical). The soft start capacitor is discharged during

TSD to ensure low output voltage overshoot and inrush currents when regulation resumes.

UNDERVOLTAGE LOCKOUT (UVLO)

If the input voltage is below the UVLO threshold, the ADP1612/

ADP1613 automatically turn off the power switch and place the part into a low power consumption mode. This prevents potentially erratic operation at low input voltages and prevents the power device from turning on when the control circuitry cannot operate it. The UVLO levels have ~100 mV of hysteresis to ensure glitch free startup.

Data Sheet

ENABLE/SHUTDOWN CONTROL

The EN input turns the ADP1612/ADP1613 regulator on or off. Drive EN low to turn off the regulator and reduce the input current to 0.01 µA, typical. Drive EN high to turn on the regulator.

When the step-up dc-to-dc switching converter is in shutdown mode (EN ≤ 0.3 V), there is a dc path from the input to the output through the inductor and output rectifier. This causes the output voltage to remain slightly below the input voltage by the forward voltage of the rectifier, preventing the output voltage from dropping

to ground when the regulator is shutdown. Figure 37 provides a

circuit modification to disconnect the output voltage from the input voltage at shutdown.

Regardless of the state of the EN pin, when a voltage is applied to

VIN of the ADP1612/ADP1613, a large current spike occurs due to the nonisolated path through the inductor and diode between

V

IN

and V

OUT

. The high current is a result of the output capacitor charging. The peak value is dependent on the inductor, output capacitor, and any load active on the output of the regulator.

Rev. D | Page 12 of 28

Data Sheet

APPLICATIONS INFORMATION

ADIsimPower DESIGN TOOL

The ADP1612/ADP1613 are supported by ADIsimPower design tool set. ADIsimPower is a collection of tools that produce complete power designs optimized for a specific design goal.

The tools enable the user to generate a full schematic, bill of materials, and calculate performance in minutes. ADIsimPower can optimize designs for cost, area, efficiency, and parts count while taking into consideration the operating conditions and limitations of the IC and all real external components. For more information about ADIsimPower design tools, refer to www.analog.com/ADIsimPower . The tool set is available from this website, and users can also request an unpopulated board through the tool.

SETTING THE OUTPUT VOLTAGE

The ADP1612/ADP1613 feature an adjustable output voltage range of V

IN

to 20 V. The output voltage is set by the resistor

voltage divider, R1 and R2, (see Figure 34) from the output

voltage (V

OUT

) to the 1.235 V feedback input at FB. Use the following equation to determine the output voltage:

V

OUT

= 1.235 × (1 + R1/R2) (1)

Choose R1 based on the following equation:

R1

=

R2

×

V

OUT

1

1 .

235

.

235

(2)

INDUCTOR SELECTION

The inductor is an essential part of the step-up switching converter. It stores energy during the on time of the power switch, and transfers that energy to the output through the output rectifier during the off time. To balance the tradeoffs between small inductor current ripple and efficiency, inductance values in the range of 4.7 µH to 22 µH are recommended.

In general, lower inductance values have higher saturation current and lower series resistance for a given physical size.

However, lower inductance results in a higher peak current that can lead to reduced efficiency and greater input and/or output ripple and noise. A peak-to-peak inductor ripple current close to 30% of the maximum dc input current typically yields an optimal compromise.

For determining the inductor ripple current in continuous operation, the input (V

IN

) and output (V

OUT

) voltages determine the switch duty cycle (D) by the following equation:

D

=

V

OUT

V

OUT

V

IN

(3)

ADP1612/ADP1613

Using the duty cycle and switching frequency, f

SW

, determine the on time by the following equation:

t

ON

=

D f

SW

(4)

The inductor ripple current (∆I

L

) in steady state is calculated by

I

L

=

V

IN

×

L t

ON

(5)

Solve for the inductance value (L) by the following equation:

L

=

V

IN

×

I

L t

ON

(6)

Ensure that the peak inductor current (the maximum input current plus half the inductor ripple current) is below the rated saturation current of the inductor. Likewise, make sure that the maximum rated rms current of the inductor is greater than the maximum dc input current to the regulator.

For CCM duty cycles greater than 50% that occur with input voltages less than one-half the output voltage, slope compensation is required to maintain stability of the current-mode regulator. For stable current-mode operation, ensure that the selected inductance is equal to or greater than the minimum calculated inductance, L

MIN

, for the application parameters in the following equation:

L

>

L

MIN

=

(

V

OUT

2 .

7

×

2

×

f

SW

V

IN

)

(7)

Inductors smaller than the 4.7 µH to 22 µH recommended range can be used as long as Equation 7 is satisfied for the given application. For input/output combinations that approach the

90% maximum duty cycle, doubling the inductor is recom-

mended to ensure stable operation. Table 5 suggests a series

of inductors for use with the ADP1612/ADP1613.

Table 5. Suggested Inductors

Manufacturer Part Series

Sumida CMD4D11

CDRH4D28CNP

Coilcraft

CDRH5D18NP

CDRH6D26HPNP

DO3308P

DO3316P

Toko

Würth

Elektronik

Dimensions

L × W × H (mm)

5.8 × 4.4 × 1.2

5.1 × 5.1 × 3.0

6.0 × 6.0 × 2.0

7.0 × 7.0 × 2.8

12.95 × 9.4 × 3.0

12.95 × 9.4 × 5.21

D52LC

D62LCB

D63LCB

WE-TPC

5.2 × 5.2 × 2.0

6.2 × 6.3 × 2.0

6.2 × 6.3 × 3.5

Assorted

WE-PD, PD2, PD3, PD4 Assorted

Rev. D | Page 13 of 28

ADP1612/ADP1613

CHOOSING THE INPUT AND OUTPUT CAPACITORS

The ADP1612/ADP1613 require input and output bypass capacitors to supply transient currents while maintaining constant input and output voltages. Use a low equivalent series resistance

(ESR), 10 µF or greater input capacitor to prevent noise at the

ADP1612/ADP1613 input. Place the capacitor between VIN and GND as close to the ADP1612/ADP1613 as possible.

Ceramic capacitors are preferred because of their low ESR characteristics. Alternatively, use a high value, medium ESR capacitor in parallel with a 0.1 µF low ESR capacitor as close to the ADP1612/ADP1613 as possible.

The output capacitor maintains the output voltage and supplies current to the load while the ADP1612/ADP1613 switch is on.

The value and characteristics of the output capacitor greatly affect the output voltage ripple and stability of the regulator. A low ESR ceramic dielectric capacitor is preferred. The output voltage ripple (∆V

OUT

) is calculated as follows:

V

OUT

=

Q

C

C

OUT

=

I

OUT

×

t

ON

C

OUT

(8) where:

Q

C

is the charge removed from the capacitor.

t

ON

is the on time of the switch.

C

OUT

is the output capacitance.

I

OUT

is the output load current.

t

ON

=

D f

SW

and

D

=

V

OUT

V

OUT

V

IN

(9)

(10)

Choose the output capacitor based on the following equation:

C

OUT

I

OUT f

SW

×

(

V

OUT

×

V

OUT

V

IN

× ∆

V

OUT

) (11)

Multilayer ceramic capacitors are recommended for this application.

DIODE SELECTION

The output rectifier conducts the inductor current to the output capacitor and load while the switch is off. For high efficiency, minimize the forward voltage drop of the diode. For this reason,

Schottky rectifiers are recommended. However, for high voltage, high temperature applications, where the Schottky rectifier reverse leakage current becomes significant and can degrade efficiency, use an ultrafast junction diode.

Data Sheet

Ensure that the diode is rated to handle the average output load current. Many diode manufacturers derate the current capability of the diode as a function of the duty cycle. Verify that the output diode is rated to handle the average output load current with the minimum duty cycle. The minimum duty cycle of the ADP1612/ADP1613 is

D

MIN

=

V

OUT

V

IN

(

MAX

)

V

OUT

(12) where V

IN(MAX)

is the maximum input voltage.

The following are suggested Schottky diode manufacturers:

• ON Semiconductor

• Diodes, Inc.

LOOP COMPENSATION

The ADP1612/ADP1613 use external components to compensate the regulator loop, allowing optimization of the loop dynamics for a given application.

The step-up converter produces an undesirable right-half plane zero in the regulation feedback loop. This requires compensating the regulator such that the crossover frequency occurs well below the frequency of the right-half plane zero. The right- half plane zero is determined by the following equation:

F

Z

(

RHP

)

=



V

IN

V

OUT



2

×

R

LOAD

2

π ×

L

(13) where:

F

Z

(RHP) is the right-half plane zero.

R

LOAD

is the equivalent load resistance or the output voltage divided by the load current.

To stabilize the regulator, ensure that the regulator crossover frequency is less than or equal to one-fifth of the right-half plane zero.

The regulator loop gain is

A

VL

=

V

FB

V

OUT

×

V

IN

V

OUT

×

G

MEA

×

R

OUT

||

Z

COMP

×

G

CS

×

Z

OUT

(14) where:

A

VL

is the loop gain.

V

FB

is the feedback regulation voltage, 1.235 V.

V

OUT

is the regulated output voltage.

V

IN

is the input voltage.

G

MEA

is the error amplifier transconductance gain.

R

OUT

is 125 MΩ.

Z

COMP

is the impedance of the series RC network from COMP to GND.

G

CS

is the current sense transconductance gain (the inductor current divided by the voltage at COMP), which is internally set by the ADP1612/ADP1613.

Z

OUT

is the impedance of the load in parallel with the output capacitor.

Rev. D | Page 14 of 28

Data Sheet

To determine the crossover frequency, it is important to note that, at that frequency, the compensation impedance (Z

COMP

) is dominated by a resistor, and the output impedance (Z

OUT

) is dominated by the impedance of an output capacitor. Therefore, when solving for the crossover frequency, the equation (by definition of the crossover frequency) is simplified to

A

VL

2

π ×

=

f

C

V

FB

V

OUT

1

×

C

×

OUT

V

IN

V

OUT

=

1

×

G

MEA

×

R

COMP

×

G

CS

×

(15)

f

where:

C

is the crossover frequency.

R

COMP

is the compensation resistor.

Solve for R

COMP

,

R

COMP

=

2

π ×

V

FB f

C

×

×

V

IN

C

OUT

×

G

×

(

MEA

V

OUT

×

G

CS

)

2

(16) where:

V

FB

= 1.235 V.

G

MEA

= 80 µA/V.

G

CS

= 13.4 A/V.

R

COMP

=

4746

×

f

C

×

C

OUT

V

IN

×

(

V

OUT

)

2

(17)

Once the compensation resistor is known, set the zero formed by the compensation capacitor and resistor to one-fourth of the crossover frequency, or

C

COMP

=

π ×

f

C

2

×

R

COMP

where C

COMP

is the compensation capacitor.

(18)

ERROR

AMPLIFIER

FB

2 g m

COMP

1

V

BG

R

COMP

C

COMP

C2

Figure 35. Compensation Components

ADP1612/ADP1613

The capacitor, C2, is chosen to cancel the zero introduced by output capacitance, ESR.

Solve for C2 as follows:

C2

=

ESR

×

C

OUT

R

COMP

(19)

For low ESR output capacitance such as with a ceramic capacitor, C2 is optional. For optimal transient performance,

R

COMP

and C

COMP

might need to be adjusted by observing the load transient response of the ADP1612/ADP1613. For most applications, the compensation resistor should be within the range of 4.7 kΩ to 100 kΩ and the compensation capacitor should be within the range of 100 pF to 3.3 nF.

SOFT START CAPACITOR

Upon startup (EN ≥ 1.6 V), the voltage at SS ramps up slowly by charging the soft start capacitor (C

SS

) with an internal 5 µA current source (I

SS

). As the soft start capacitor charges, it limits the peak current allowed by the part to prevent excessive overshoot at startup. The necessary soft start capacitor, C

SS

, for a specific overshoot and start-up time can be calculated for the maximum load condition when the part is at current limit by:

C

SS

=

I

SS

t

V

SS

(20) where:

I

SS

= 5 μA (typical).

V

SS

= 1.2 V.

Δt = startup time, at current limit.

If the applied load does not place the part at current limit, the necessary C

SS

will be smaller. A 33 nF soft start capacitor results in negligible input current overshoot at start up, and therefore is suitable for most applications. However, if an unusually large output capacitor is used, a longer soft start period is required to prevent input inrush current.

Conversely, if fast startup is a requirement, the soft start capacitor can be reduced or removed, allowing the

ADP1612/ADP1613 to start quickly, but allowing greater peak switch current.

Rev. D | Page 15 of 28

ADP1612/ADP1613

TYPICAL APPLICATION CIRCUITS

Both the ADP1612 and ADP1613 can be used in the application circuits in this section.

The ADP1612 is geared toward applications requiring input voltages as low as 1.8 V, where the ADP1613 is more suited for applications needing the output power capabilities of a 2.0 A

switch. The primary differences are shown in Table 6.

Table 6. ADP1612/ADP1613 Differences

Parameter ADP1612

Current Limit

Input Voltage Range

1.4 A

1.8 V to 5.5 V

ADP1613

2.0 A

2.5 V to 5.5 V

The Step-Up Regulator Circuit Examples section recommends

component values for several common input, output, and load

conditions. The equations in the Applications Information

section can be used to select components for alternate configurations.

STEP-UP REGULATOR

The circuit in Figure 36 shows the ADP1612/ADP1613 in a

basic step-up configuration.

L1

V

IN

C

IN

6

VIN

ADP1612/

ADP1613

SW

5

ON

OFF 3 EN

650kHz

(DEFAULT)

1.3MHz

7 FREQ

8

SS

C

SS

GND

4

FB 2

COMP

1

D1

R1

R2

V

OUT

R

COMP

C

COMP

C

OUT

Figure 36. Step-Up Regulator

The modified step-up circuit in Figure 37 incorporates true

shutdown capability advantageous for battery-powered applications requiring low standby current. Driving the EN pin below

0.3 V shuts down the ADP1612/ADP1613 and completely disconnects the input from the output.

L1

V

IN

NTGD1100L

Q1

A

R3

10kΩ

6

ADP1612/

ADP1613

VIN SW

5

Q1

B

OFF

ON

3

C

IN

1.3MHz

650kHz

(DEFAULT)

7

8

EN

FREQ

C

SS

FB

SS COMP

GND

4

2

1

D1

R1

R2

R

COMP

C

COMP

V

OUT

C

OUT

Figure 37. Step-Up Regulator with True Shutdown

Rev. D | Page 16 of 28

STEP-UP REGULATOR CIRCUIT EXAMPLES

ADP1612 Step-Up Regulator

L1

4.7µH

D1

3A, 40V

V

OUT

= 5V V

IN

= 1.8V TO 4.2V

C

IN

10µF

OFF

ON

6

3

VIN SW

EN

ADP1612

FB

7

FREQ

5

2

COMP

1

8 SS

C

SS

33nF

GND

4

R1

30kΩ

R2

10kΩ

R

COMP

6.8kΩ

C

COMP

3300pF

C

OUT

10µF

L1: DO3316P-472ML

D1: MBRA340T3G

R1: RC0805FR-0730KL

R2: CRCW080510K0FKEA

R

COMP

: RC0805JR-076K8L

C

COMP

: ECJ-2VB1H332K

C

IN

: GRM21BR61C106KE15L

C

OUT

: GRM32DR71E106KA12L

C

SS

: ECJ-2VB1H333K

Figure 38. ADP1612 Step-Up Regulator Configuration

V

OUT

= 5 V, f

SW

= 650 kHz

100

90 f

V

OUT

= 5V

SW

= 650kHz

T

A

= 25°C

80

70

ADP1612

60

50

40

30

1

V

IN

= 1.8V

V

IN

= 2.7V

V

IN

= 3.3V

V

IN

= 4.2V

10 100

LOAD CURRENT (mA)

1k

Figure 39. ADP1612 Efficiency vs. Load Current

V

OUT

= 5 V, f

SW

= 650 kHz

10k

T

OUTPUT VOLTAGE (50mV/DIV)

AC-COUPLED f

V

OUT

= 5V

SW

= 650kHz

LOAD CURRENT (50mA/DIV)

Data Sheet

TIME (100µs/DIV)

Figure 40. ADP1612 50 mA to 150 mA Load Transient (V

IN

= 3.3 V)

V

OUT

= 5 V, f

SW

= 650 kHz

Data Sheet

L1

4.7µH

V

IN

= 1.8V TO 4.2V

C

IN

10µF

OFF

ON

6

3

VIN SW

ADP1612

EN

FB

7

FREQ

5

2

COMP

1

8

SS

C

SS

33nF

GND

4

D1

3A, 40V

V

OUT

= 5V

R1

30kΩ

R2

10kΩ

R

COMP

12kΩ

C

COMP

1200pF

C

OUT

10µF

L1: DO3316P-472ML

D1: MBRA340T3G

R1: RC0805FR-0730KL

R2: CRCW080510K0FKEA

R

COMP

: RC0805JR-0712KL

C

COMP

: ECJ-2VB1H122K

C

IN

: GRM21BR61C106KE15L

C

OUT

: GRM32DR71E106KA12L

C

SS

: ECJ-2VB1H333K

Figure 41. ADP1612 Step-Up Regulator Configuration

V

OUT

= 5 V, f

SW

= 1.3 MHz

100

90

V

OUT

= 5V f

SW

= 1.3MHz

T

A

= 25°C

80

ADP1612

70

60

50

40

30

1

V

IN

= 1.8V

V

IN

= 2.7V

V

IN

= 3.3V

V

IN

= 4.2V

10 100

LOAD CURRENT (mA)

1k

Figure 42. ADP1612 Efficiency vs. Load Current

V

OUT

= 5 V, f

SW

= 1.3 MHz

10k

T

OUTPUT VOLTAGE (50mV/DIV)

AC-COUPLED f

V

OUT

= 5V

SW

= 1.3MHz

LOAD CURRENT (50mA/DIV)

ADP1612/ADP1613

L1

10µH

V

IN

= 2.7V TO 5V

C

IN

10µF

OFF

ON

6

3

VIN SW

EN

ADP1612

FB

7

FREQ

5

2

COMP

1

8

SS

C

SS

33nF

GND

4

D1

2A, 20V

V

OUT

= 12V

R1

86.6kΩ

R2

10kΩ

R

COMP

22kΩ

C

COMP

1800pF

C

OUT

10µF

L1: DO3316P-103ML

D1: DFLS220L-7

R1: ERJ-6ENF8662V

R2: CRCW080510K0FKEA

R

COMP

: RC0805JR-0722KL

C

COMP

: ECJ-2VB1H182K

C

IN

: GRM21BR61C106KE15L

C

OUT

: GRM32DR71E106KA12L

C

SS

: ECJ-2VB1H333K

Figure 44. ADP1612 Step-Up Regulator Configuration

V

OUT

= 12 V, f

SW

= 650 kHz

100

90

V

OUT

= 12V f

SW

= 650kHz

T

A

= 25°C

ADP1612

80

70

60

50

40

1

V

IN

= 2.7V

V

IN

= 3.3V

V

IN

= 4.2V

V

IN

= 5.0V

10 100

LOAD CURRENT (mA)

Figure 45. ADP1612 Efficiency vs. Load Current

V

OUT

= 12 V, f

SW

= 650 kHz

1k

T

OUTPUT VOLTAGE (100mV/DIV)

AC-COUPLED f

V

OUT

= 12V

SW

= 650kHz

LOAD CURRENT (50mA/DIV)

TIME (100µs/DIV)

Figure 43. ADP1612 50 mA to 150 mA Load Transient (V

IN

= 3.3 V)

V

OUT

= 5 V, f

SW

= 1.3 MHz

TIME (100µs/DIV)

Figure 46. ADP1612 50 mA to 150 mA Load Transient (V

IN

= 3.3 V)

V

OUT

= 12 V, f

SW

= 650 kHz

Rev. D | Page 17 of 28

ADP1612/ADP1613

L1

6.8µH

V

IN

= 2.7V TO 5V

C

IN

10µF

OFF

ON

6

3

VIN SW

ADP1612

EN

5

FB 2

7

FREQ

COMP

1

8

SS

C

SS

33nF

GND

4

D1

2A, 20V

V

OUT

= 12V

R1

86.6kΩ

C

OUT

10µF

R2

10kΩ

R

COMP

18kΩ

C

COMP

680pF

L1: DO3316P-682ML

D1: DFLS220L-7

R1: ERJ-6ENF8662V

R2: CRCW080510K0FKEA

R

COMP

: RC0805JR-0718KL

C

COMP

: CC0805KRX7R9BB681

C

IN

: GRM21BR61C106KE15L

C

OUT

: GRM32DR71E106KA12L

C

SS

: ECJ-2VB1H333K

Figure 47. ADP1612 Step-Up Regulator Configuration

V

OUT

= 12 V, f

SW

= 1.3 MHz

100

90 f

V

OUT

= 12V

SW

= 1.3MHz

T

A

= 25°C

80

ADP1612

70

60

50

40

30

1

V

IN

= 2.7V

V

IN

= 3.3V

V

IN

= 4.2V

V

IN

= 5.0V

10 100

LOAD CURRENT (mA)

Figure 48. ADP1612 Efficiency vs. Load Current

V

OUT

= 12 V, f

SW

= 1.3 MHz

1k

T

OUTPUT VOLTAGE (100mV/DIV)

AC-COUPLED

V

OUT

= 12V f

SW

= 1.3MHz

LOAD CURRENT (50mA/DIV)

TIME (100µs/DIV)

Figure 49. ADP1612 50 mA to 150 mA Load Transient (V

IN

= 3.3 V)

V

OUT

= 12 V, f

SW

= 1.3 MHz

Data Sheet

L1

15µH

V

IN

= 2.7V TO 5V

C

IN

10µF

OFF

ON

6

3

VIN SW

EN

ADP1612

FB

7

FREQ

5

2

COMP

1

8

SS

C

SS

33nF

GND

4

D1

2A, 20V

V

OUT

= 15V

R1

1

10kΩ

R2

10kΩ

R

COMP

22kΩ

C

COMP

1800pF

C

OUT

10µF

L1: DO3316P-153ML

D1: DFLS220L-7

R1: ERJ-6ENF1103V

R2: CRCW080510K0FKEA

R

COMP

: RC0805JR-0722KL

C

COMP

: ECJ-2VB1H182K

C

IN

: GRM21BR61C106KE15L

C

OUT

: GRM32DR71E106KA12L

C

SS

: ECJ-2VB1H333K

Figure 50. ADP1612 Step-Up Regulator Configuration

V

OUT

= 15 V, f

SW

= 650 kHz

100

90

V

OUT

= 15V f

SW

= 650kHz

T

A

= 25°C

ADP1612

80

70

60

50

40

1

V

IN

= 2.7V

V

IN

= 3.3V

V

IN

= 4.2V

V

IN

= 5.0V

10 100

LOAD CURRENT (mA)

Figure 51. ADP1612 Efficiency vs. Load Current

V

OUT

= 15 V, f

SW

= 650 kHz

1k

T

OUTPUT VOLTAGE (200mV/DIV)

AC-COUPLED f

V

OUT

= 15V

SW

= 650kHz

LOAD CURRENT (50mA/DIV)

TIME (100µs/DIV)

Figure 52. ADP1612 50 mA to 150 mA Load Transient (V

IN

= 3.3 V)

V

OUT

= 15 V, f

SW

= 650 kHz

Rev. D | Page 18 of 28

Data Sheet

L1

10µH

V

IN

= 2.7V TO 5V

C

IN

10µF

OFF

ON

6

3

VIN

SW

ADP1612

EN

FB

5

2

7 FREQ

COMP 1

8 SS

C

SS

33nF

GND

4

D1

2A, 20V

V

OUT

= 15V

R1

1

10kΩ

R2

10kΩ

R

COMP

10kΩ

C

COMP

1800pF

C

OUT

10µF

L1: DO3316P-103ML

D1: DFLS220L-7

R1: ERJ-6ENF1103V

R2: CRCW080510K0FKEA

R

COMP

: RC0805JR-0710KL

C

COMP

: ECJ-2VB1H182K

C

IN

: GRM21BR61C106KE15L

C

OUT

: GRM32DR71E106KA12L

C

SS

: ECJ-2VB1H333K

Figure 53. ADP1612 Step-Up Regulator Configuration

V

OUT

=15 V, f

SW

= 1.3 MHz

100

90

V

OUT

= 15V f

SW

= 1.3MHz

T

A

= 25°C

80

70

ADP1612

60

50

40

30

1

V

IN

= 2.7V

V

IN

= 3.3V

V

IN

= 4.2V

V

IN

= 5.0V

10 100

LOAD CURRENT (mA)

Figure 54. ADP1612 Efficiency vs. Load Current

V

OUT

=15 V, f

SW

= 1.3 MHz

1k

T

OUTPUT VOLTAGE (200mV/DIV)

AC-COUPLED f

V

OUT

= 15V

SW

= 1.3MHz

LOAD CURRENT (50mA/DIV)

ADP1612/ADP1613

ADP1613 Step-Up Regulator

L1

10µH

V

IN

= 2.7V TO 5V

C

IN

10µF

OFF

ON

6

3

VIN SW

EN

ADP1613

FB

7

FREQ

5

2

COMP

1

8

SS

C

SS

33nF

GND

4

D1

3A, 40V

V

OUT

= 12V

R1

86.6kΩ

R2

10kΩ

R

COMP

12kΩ

C

COMP

2200pF

C

OUT

10µF

L1: DO3316P-103ML

D1: MBRA340T3G

R1: ERJ-6ENF8662V

R2: CRCW080510K0FKEA

R

COMP

: RC0805JR-0712KL

C

COMP

: ECJ-2VB1H222K

C

IN

: GRM21BR61C106KE15L

C

OUT

: GRM32DR71E106KA12L

C

SS

: ECJ-2VB1H333K

Figure 56. ADP1613 Step-Up Regulator Configuration

V

OUT

= 12 V, f

SW

= 650 kHz

100

90

V

OUT

= 12V f

SW

= 650kHz

T

A

= 25°C

80

ADP1613

70

60

50

40

30

1

V

IN

= 2.7V

V

IN

= 3.3V

V

IN

= 4.2V

V

IN

= 5.0V

10 100

LOAD CURRENT (mA)

Figure 57. ADP1613 Efficiency vs. Load Current

V

OUT

= 12 V, f

SW

= 650 kHz

1k

T

OUTPUT VOLTAGE (200mV/DIV)

AC-COUPLED f

V

OUT

= 12V

SW

= 650kHz

LOAD CURRENT (50mA/DIV)

TIME (100µs/DIV)

Figure 55. ADP1612 50 mA to 150 mA Load Transient (V

IN

= 3.3 V)

V

OUT

=15 V, f

SW

= 1.3 MHz

Rev. D | Page 19 of 28

TIME (100µs/DIV)

Figure 58. ADP1613 50 mA to 150 mA Load Transient (V

IN

= 5 V)

V

OUT

= 12 V, f

SW

= 650 kHz

ADP1612/ADP1613

L1

6.8µH

V

IN

= 2.7V TO 5V

C

IN

10µF

OFF

ON

6

3

VIN

SW

ADP1613

EN

FB

5

2

7 FREQ

COMP 1

8 SS

C

SS

33nF

GND

4

D1

3A, 40V

V

OUT

= 12V

R1

86.6kΩ

R2

10kΩ

R

COMP

10kΩ

C

COMP

1000pF

C

OUT

10µF

L1: DO3316P-682ML

D1: MBRA340T3G

R1: ERJ-6ENF8662V

R2: CRCW080510K0FKEA

R

COMP

: RC0805JR-0710KL

C

COMP

: ECJ-2VB1H102K

C

IN

: GRM21BR61C106KE15L

C

OUT

: GRM32DR71E106KA12L

C

SS

: ECJ-2VB1H333K

Figure 59. ADP1613 Step-Up Regulator Configuration

V

OUT

= 12 V, f

SW

= 1.3 MHz

100

90 f

V

OUT

= 12V

SW

= 1.3MHz

T

A

= 25°C

80

ADP1613

70

60

50

40

30

1

V

IN

= 2.7V

V

IN

= 3.3V

V

IN

= 4.2V

V

IN

= 5.0V

10 100

LOAD CURRENT (mA)

Figure 60. ADP1613 Efficiency vs. Load Current

V

OUT

= 12 V, f

SW

= 1.3 MHz

1k

T

OUTPUT VOLTAGE (100mV/DIV)

AC-COUPLED f

V

OUT

= 12V

SW

= 1.3MHz

LOAD CURRENT (50mA/DIV)

Data Sheet

L1

15µH

V

IN

= 3.3V TO 5.5V

C

IN

10µF

OFF

ON

6

3

VIN

SW

EN

ADP1613

FB

5

2

7 FREQ

COMP 1

8 SS

C

SS

33nF

GND

4

D1

3A, 40V

V

OUT

= 15V

R1

1

10kΩ

R2

10kΩ

R

COMP

10kΩ

C

COMP

1800pF

C

OUT

10µF

L1: DO3316P-153ML

D1: MBRA340T3G

R1: ERJ-6ENF1103V

R2: CRCW080510K0FKEA

R

COMP

: RC0805JR-0710KL

C

COMP

: ECJ-2VB1H182K

C

IN

: GRM21BR61C106KE15L

C

OUT

: GRM32DR71E106KA12L

C

SS

: ECJ-2VB1H333K

Figure 62. ADP1613 Step-Up Regulator Configuration

V

OUT

= 15 V, f

SW

= 650 kHz

100

90

V

OUT

= 15V f

SW

= 650kHz

T

A

= 25°C

80

ADP1613

70

60

50

40

30

1

V

IN

= 3.3V

V

IN

= 4.2V

V

IN

= 5.0V

V

IN

= 5.5V

10 100

LOAD CURRENT (mA)

Figure 63. ADP1613 Efficiency vs. Load Current

V

OUT

= 15 V, f

SW

= 650 kHz

1k

T

OUTPUT VOLTAGE (200mV/DIV)

AC-COUPLED f

V

OUT

= 15V

SW

= 650kHz

LOAD CURRENT (50mA/DIV)

TIME (100µs/DIV)

Figure 61. ADP1613 50 mA to 150 mA Load Transient (V

IN

= 5 V)

V

OUT

= 12 V, f

SW

= 1.3 MHz

TIME (100µs/DIV)

Figure 64. ADP1613 50 mA to 150 mA Load Transient (V

IN

= 5 V)

V

OUT

= 15 V, f

SW

= 650 kHz

Rev. D | Page 20 of 28

Data Sheet

L1

10µH

V

IN

= 3.3V TO 5.5V

C

IN

10µF

OFF

ON

6

3

VIN SW

ADP1613

EN

5

FB 2

7

FREQ

COMP

1

8

SS

C

SS

33nF

GND

4

D1

3A, 40V

V

OUT

= 15V

R1

1

10kΩ

C

OUT

10µF

R2

10kΩ

R

COMP

8.2kΩ

C

COMP

1200pF

L1: DO3316P-103ML

D1: MBRA340T3G

R1: ERJ-6ENF1103V

R2: CRCW080510K0FKEA

R

COMP

: RC0805JR-078K2L

C

COMP

: ECJ-2VB1H122K

C

IN

: GRM21BR61C106KE15L

C

OUT

: GRM32DR71E106KA12L

C

SS

: ECJ-2VB1H333K

Figure 65. ADP1613 Step-Up Regulator Configuration

V

OUT

= 15 V, f

SW

= 1.3 MHz

70

60

50

100

90 f

V

OUT

= 15V

SW

= 1.3MHz

T

A

= 25°C

80

ADP1613

40

30

20

1

V

IN

= 3.3V

V

IN

= 4.2V

V

IN

= 5.0V

V

IN

= 5.5V

10 100

LOAD CURRENT (mA)

Figure 66. ADP1613 Efficiency vs. Load Current

V

OUT

= 15 V, f

SW

= 1.3 MHz

1k

T

OUTPUT VOLTAGE (200mV/DIV)

AC-COUPLED f

V

OUT

= 15V

SW

= 1.3MHz

LOAD CURRENT (50mA/DIV)

ADP1612/ADP1613

L1

15µH

V

IN

= 3.3V TO 5.5V

C

IN

10µF

OFF

ON

6

3

VIN SW

EN

ADP1613

FB

7

FREQ

5

2

COMP

1

8

SS

C

SS

33nF

GND

4

D1

3A, 40V

V

OUT

= 20V

R1

150kΩ

R2

10kΩ

R

COMP

18kΩ

C

COMP

820pF

C

OUT

10µF

L1: DO3316P-153ML

D1: MBRA340T3G

R1: RC0805JR-07150KL

R2: CRCW080510K0FKEA

R

COMP

: RC0805JR-0718KL

C

COMP

: CC0805KRX7R9BB821

C

IN

: GRM21BR61C106KE15L

C

OUT

: GRM32DR71E106KA12L

C

SS

: ECJ-2VB1H333K

Figure 68. ADP1613 Step-Up Regulator Configuration

V

OUT

= 20 V, f

SW

= 650 kHz

100

90

V

OUT

= 20V f

SW

= 650kHz

T

A

= 25°C

80

ADP1613

70

60

50

40

30

1

V

IN

= 3.3V

V

IN

= 4.2V

V

IN

= 5.0V

V

IN

= 5.5V

10 100

LOAD CURRENT (mA)

Figure 69. ADP1613 Efficiency vs. Load Current

V

OUT

= 20 V, f

SW

= 650 kHz

1k

T

OUTPUT VOLTAGE (200mV/DIV)

AC-COUPLED f

V

OUT

= 20V

SW

= 650kHz

LOAD CURRENT (50mA/DIV)

TIME (100µs/DIV)

Figure 67. ADP1613 50 mA to 150 mA Load Transient (V

IN

= 5 V)

V

OUT

= 15 V, f

SW

= 1.3 MHz

TIME (100µs/DIV)

Figure 70. ADP1613 50 mA to 150 mA Load Transient (V

IN

= 5 V)

V

OUT

= 20 V, f

SW

= 650 kHz

Rev. D | Page 21 of 28

ADP1612/ADP1613

L1

10µH

V

IN

= 3.3V TO 5.5V

C

IN

10µF

OFF

ON

6

3

VIN SW

ADP1613

EN

5

FB 2

7

FREQ

COMP

1

8

SS

C

SS

33nF

GND

4

D1

3A, 40V

V

OUT

= 20V

R1

150kΩ

C

OUT

10µF

R2

10kΩ

R

COMP

8.2kΩ

C

COMP

1200pF

70

60

50

L1: DO3316P-103ML

D1: MBRA340T3G

R1: RC0805JR-07150KL

R2: CRCW080510K0FKEA

R

COMP

: RC0805JR-078K2L

C

COMP

: ECL-2VB1H122K

C

IN

: GRM21BR61C106KE15L

C

OUT

: GRM32DR71E106KA12L

C

SS

: ECJ-2VB1H333K

Figure 71. ADP1613 Step-Up Regulator Configuration

V

OUT

= 20 V, f

SW

= 1.3 MHz

100

90 f

V

OUT

= 20V

SW

= 1.3MHz

T

A

= 25°C

80

ADP1613

40

30

20

1

V

IN

= 3.3V

V

IN

= 4.2V

V

IN

= 5.0V

V

IN

= 5.5V

10 100

LOAD CURRENT (mA)

Figure 72. ADP1613 Efficiency vs. Load Current

V

OUT

= 20 V, f

SW

= 1.3 MHz

1k

T

OUTPUT VOLTAGE (200mV/DIV)

AC-COUPLED f

V

OUT

= 20V

SW

= 1.3MHz

LOAD CURRENT (50mA/DIV)

Data Sheet

SEPIC CONVERTER

The circuit in Figure 74 shows the ADP1612/ADP1613 in a

single-ended primary inductance converter (SEPIC) topology.

This topology is useful for an unregulated input voltage, such as a battery-powered application in which the input voltage can vary between 2.7 V to 5 V and the regulated output voltage falls within the input voltage range.

The input and the output are dc isolated by a coupling capacitor

(C1). In steady state, the average voltage of C1 is the input voltage.

When the ADP1612/ADP1613 switch turns on and the diode turns off, the input voltage provides energy to L1 and C1 provides energy to L2. When the ADP1612/ADP1613 switch turns off and the diode turns on, the energy in L1 and L2 is released to charge the output capacitor (C

OUT

) and the coupling capacitor

(C1) and to supply current to the load.

L1

DO3316P

4.7µH

V

IN

= 2.0V TO 5.5V

6 VIN

ADP1612/

ADP1613

SW 5

OFF

ON

3

EN

C

IN

10µF

7 FREQ

FB 2

C1

10µF

MBRA210LT

2A, 10V

L2

DO3316P

4.7µH

R1

16.9kΩ

V

OUT

= 3.3V

C

SS

8

SS

GND

4

COMP

1

R

COMP

82kΩ

C

COMP

220pF

R2

10kΩ

C

OUT

10µF

Figure 74. SEPIC Converter

TFT LCD BIAS SUPPLY

Figure 75 shows a power supply circuit for TFT LCD module

applications. This circuit has +10 V, −5 V, and +22 V outputs.

The +10 V is generated in the step-up configuration. The −5 V and +22 V are generated by the charge-pump circuit. During the step-up operation, the SW node switches between +10 V and ground (neglecting the forward drop of the diode and on resistance of the switch). When the SW node is high, C5 charges up to +10 V. When the SW node is low, C5 holds its charge and forward-biases D8 to charge C6 to −10 V. The Zener diode (D9) clamps and regulates the output to −5 V.

The VGH output is generated in a similar manner by the chargepump capacitors, C1, C2, and C4. The output voltage is tripled and regulated down to 22 V by the Zener diode, D5.

TIME (100µs/DIV)

Figure 73. ADP1613 50 mA to 150 mA Load Transient (V

IN

= 5 V)

V

OUT

= 20 V, f

SW

= 1.3 MHz

Rev. D | Page 22 of 28

Data Sheet ADP1612/ADP1613

VGL

–5V

D9

BZT52C5VIS

R4

200Ω

C6

10µF

BAV99

D8

D7

DO3316P

4.7µH

V

IN

= 3.3V

C

IN

10µF

6 VIN

ADP1612/

ADP1613

SW 5

ON

OFF 3 EN

650kHz

(DEFAULT)

1.3MHz

7

FREQ

8 SS

C

SS

GND

4

FB 2

COMP 1

C5

10nF

C4

10nF

BAV99

D5

C1

10nF

D4

BAV99

D3

C3

10µF

C2

1µF

D2

R3

200Ω

D1

R

COMP

27kΩ

C

COMP

1200pF

R1

71.5kΩ

R2

10kΩ

V

OUT

= 10V

C

OUT

10µF

D5

BZT52C22

VGH

+22V

Figure 75. TFT LCD Bias Supply

Rev. D | Page 23 of 28

ADP1612/ADP1613

PCB LAYOUT GUIDELINES

Figure 76. Example Layout for ADP1612/ADP1613 Boost Application

(Top Layer)

Data Sheet

For high efficiency, good regulation, and stability, a well-designed printed circuit board layout is required.

Use the following guidelines when designing printed circuit

boards (also see Figure 34 for a block diagram and Figure 3

for a pin configuration).

• Keep the low ESR input capacitor, C

IN

(labeled as C7 in

Figure 76), close to VIN and GND. This minimizes noise

injected into the part from board parasitic inductance.

• Keep the high current path from C

IN

(labeled as C7 in

Figure 76) through the L1 inductor to SW and GND as

short as possible.

• Keep the high current path from VIN through L1, the rectifier (D1) and the output capacitor, C

OUT

(labeled as

C4 in Figure 76) as short as possible.

• Keep high current traces as short and as wide as possible.

• Place the feedback resistors as close to FB as possible to prevent noise pickup. Connect the ground of the feedback network directly to an AGND plane that makes a Kelvin connection to the GND pin.

• Place the compensation components as close as possible to

COMP. Connect the ground of the compensation network directly to an AGND plane that makes a Kelvin connection to the GND pin.

• Connect the softstart capacitor, C

SS

(labeled as C1 in

Figure 76) as close to the device as possible. Connect the

ground of the softstart capacitor to an AGND plane that makes a Kelvin connection to the GND pin.

• Avoid routing high impedance traces from the compensation and feedback resistors near any node connected to SW or near the inductor to prevent radiated noise injection.

Figure 77. Example Layout for ADP1612/ADP1613 Boost Application

(Bottom Layer)

Rev. D | Page 24 of 28

Data Sheet

OUTLINE DIMENSIONS

ADP1612/ADP1613

3.20

3.00

2.80

3.20

3.00

2.80

8 5 5.15

4.90

4.65

1

4

PIN 1

IDENTIFIER

0.65 BSC

0.95

0.85

0.75

0.15

0.05

COPLANARITY

0.10

0.40

0.25

1.10 MAX

15° MAX

0.23

0.09

0.80

0.55

0.40

COMPLIANT TO JEDEC STANDARDS MO-187-AA

Figure 78. 8-Lead Mini Small Outline Package [MSOP]

(RM-8)

Dimensions shown in millimeters

ORDERING GUIDE

Model

1

ADP1612ARMZ-R7

ADP1612-5-EVALZ

ADP1613ARMZ-R7

ADP1613-12-EVALZ

1 Z = RoHS Compliant Part.

Temperature Range Package Description

2

−40°C to +125°C

−40°C to +125°C

8-Lead Mini Small Outline Package [MSOP]

Evaluation Board, 5 V Output Voltage Configuration

Package Option

RM-8

8-Lead Mini Small Outline Package [MSOP]

Evaluation Board, 12 V Output Voltage Configuration

RM-8

Branding

L7Z

L96

Rev. D | Page 25 of 28

ADP1612/ADP1613

NOTES

Data Sheet

Rev. D | Page 26 of 28

Data Sheet

NOTES

ADP1612/ADP1613

Rev. D | Page 27 of 28

ADP1612/ADP1613

NOTES

Data Sheet

©2009–2012 Analog Devices, Inc. All rights reserved. Trademarks and

registered trademarks are the property of their respective owners.

D06772-0-11/12(D)

Rev. D | Page 28 of 28

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