LTC3400-1

FEATURES

■

■

■

■

■

■

■

■

■

■

Up to 92% Efficiency

Generates 3.3V at 100mA from a Single AA Cell

Low Start-Up Voltage: 0.85V

V

OUT

Connected to V

IN

in Shutdown

Internal Synchronous Rectifier

2.5V to 5V Output Range

Automatic Burst Mode

®

Operation

Logic Controlled Shutdown (< 1µA)

Antiringing Control Minimizes EMI

Tiny External Components

■ Low Profile (1mm) SOT-23 Package

U

APPLICATIO S

■

■

■

■

■

■

■

Pagers

MP3 Players

Digital Cameras

LCD Bias Supplies

Handheld Instruments

Wireless Handsets

GPS Receivers

600mA, 1.2MHz Micropower

Synchronous Boost Converter in ThinSOT

U

DESCRIPTIO

The LTC

®

3400-1 is a synchronous, fixed frequency, stepup DC/DC converter delivering high efficiency in a 6-lead

ThinSOT™ package. Capable of supplying 3.3V at 100mA from a single AA cell input, the device contains an internal

NMOS switch and PMOS synchronous rectifier.

A switching frequency of 1.2MHz minimizes solution footprint by allowing the use of tiny, low profile inductors and ceramic capacitors. The current mode PWM design is internally compensated, reducing external parts count.

The LTC3400-1 features automatic shifting to power saving Burst Mode operation at light loads. In shutdown, V

OUT and V

IN are connected, which allows the input battery to be used for backup power. The LTC3400-1 features low shutdown current of under 1µA.

The LTC3400-1 is offered in the low profile (1mm)

SOT-23 package.

, LTC, LT and Burst Mode are registered trademarks of Linear Technology Corporation.

ThinSOT is a trademark of Linear Technology Corporation.

US Patent Numbers 5,481,178; 6,580,258; 6,304,066; 6,127,815; 6,498,466; 6,611,131.

TYPICAL APPLICATIO

U

Single Cell to 3.3V Synchronous Boost Converter

4.7µH

+

SINGLE

AA CELL

4.7µF

OFF ON

V

IN

SW

V

OUT

LTC3400-1

SHDN

GND

FB

1.02M

1%

604k

1%

V

OUT

3.3V

100mA

4.7µF

34001 F01

Efficiency

100

90

80

V

IN

= 2.4V

V

IN

= 1.5V

70

60

50

40

0.1

FIGURE 1 CIRCUIT

WITH OPTIONAL SCHOTTKY DIODE

(SEE APPLICATIONS INFORMATION)

1 10 100

LOAD CURRENT (mA)

1000

34001 F01a

34001f

1

LTC3400-1

W W W U

ABSOLUTE AXI U RATI GS

(Note 1)

V

IN

Voltage ................................................. – 0.3V to 6V

SW Voltage

DC .......................................................... – 0.3V to 6V

Pulsed (<100ns) ...................................... – 0.3V to 7V

SHDN, FB Voltage ....................................... – 0.3V to 6V

V

OUT

........................................................... – 0.3V to 6V

Operating Temperature Range (Note 2) .. – 30°C to 85°C

Storage Temperature Range ................... – 65°C to 125°

Lead Temperature (Soldering, 10 sec).................. 300°C

U W

PACKAGE/ORDER I FOR ATIO

U

TOP VIEW

SW 1

GND 2

FB 3

6 V

IN

5 V

OUT

4 SHDN

S6 PACKAGE

6-LEAD PLASTIC TSOT-23

T

JMAX

= 125°C, θ

JC

= 102°C/W

ORDER PART

NUMBER

LTC3400ES6-1

S6 PART MARKING

LTBJM

Consult LTC Marketing for parts specified with wider operating temperature ranges.

ELECTRICAL CHARACTERISTICS

temperature range, otherwise specifications are at T

A

The

●

denotes the specifications which apply over the full operating

= 25°C. V

IN

= 1.2V, V

OUT

= 3.3V, unless otherwise specified.

MIN PARAMETER

Minimum Start-Up Voltage

Minimum Operating Voltage

Output Voltage Adjust Range

Feedback Voltage

Feedback Input Current

Quiescent Current (Burst Mode Operation)

Quiescent Current (Shutdown)

Quiescent Current (Active)

NMOS Switch Leakage

PMOS Switch Leakage

NMOS Switch On Resistance

PMOS Switch On Resistance

CONDITIONS

I

LOAD

= 1mA

SHDN = V

IN

(Note 4)

V

FB

= 1.25V (Note 3)

V

FB

= 1.4V (Note 5)

V

SHDN

= 0V, Not Including Switch Leakage, V

IN

= V

OUT

Measured On V

OUT

V

SW

= 5V

V

SW

= 0V (Note 3)

V

OUT

= 3.3V

V

OUT

= 5V

V

OUT

= 3.3V

V

OUT

= 5V

●

2.5

1.192

TYP

0.85

0.5

30

1

500

5

MAX

1

0.65

5

1.268

NMOS Current Limit

Burst Mode Operation Current Threshold

Current Limit Delay to Output

Max Duty Cycle

Switching Frequency

(Note 3)

(Note 3)

V

FB

= 1.15V

●

●

600

80

0.95

0.85

1

300

0.1

0.1

0.35

0.20

1.23

1

19

0.01

0.45

0.30

850

3

40

87

1.2

1.2

1.5

1.5

SHDN Input High

SHDN Input Low

SHDN Input Current V

SHDN

= 5.5V

0.01

0.35

1

Ω

Ω mA mA ns

%

MHz

MHz

V

V

µA

UNITS

V

V

V

V nA

µA

µA

µA

µA

µA

Ω

Ω

Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired.

Note 2: The LTC3400-1 is guaranteed to meet performance specifications from 0°C to 70°C. Specifications over the – 30°C to 85°C operating temperature range are assured by design, characterization and correlation with statistical process controls.

Note 3: Specification is guaranteed by design and not 100% tested in production.

Note 4: Minimum V

IN

operation after start-up is only limited by the battery’s ability to provide the necessary power as it enters a deeply discharged state.

Note 5: Burst Mode operation I

Q

is measured at V

OUT

. Multiply this value by V

OUT

/V

IN

to get the equivalent input (battery) current.

34001f

2

LTC3400-1

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TYPICAL PERFOR A CE CHARACTERISTICS

20

Output Load Burst Mode Threshold vs V

IN

L = 4.7µH

T

A

= 25°C

V

OUT

= 3.3V

V

OUT

= 5V

10

0

0.9

1.5

2.1

2.7

V

IN

(V)

3.3

3.9

4.5

3400 G01

No Load Battery Current vs V

BATT

1000

V

OUT

= 3.3V

T

A

= 25°C

100

10

0.9

1.2

1.5

1.8

2.1

2.4

BATTERY VOLTAGE (V)

2.7

3.0

3400 G04

SW Pin Fixed Frequency,

Continuous Inductor Current

Operation

V

OUT

vs Temperature

3.36

FIGURE 1 CIRCUIT

I

O

= 10mA

3.34

3.32

3.30

3.28

3.26

3.24

–60

–30

0 30 60

TEMPERATURE (°C)

90 120

3400 G02

1.01

Normalized Oscillator Frequency vs Temperature

1.00

0.99

0.98

0.97

0.96

0.95

–50 –30 –10 10

30

50

TEMPERATURE (°C)

70 90

3400 G05

Fixed Frequency and Burst Mode

Operation

V

SW

1V/DIV

Minimum Start-Up Voltage vs Load Current

1.4

T

A

= 25°C

1.3

1.2

1.1

1.0

0.9

0.8

0.1

1 10

I

OUT

(mA) CURRENT SOURCE LOAD

100

3400 G03

SW Pin Antiringing Operation

0V

I

V

IN

= 1.3V

V

OUT

OUT

= 3.3V

= 10mA

L = 6.8µH

C

OUT

= 4.7µF

100ns/DIV

V

OUT

Transient Response

3400 G06

V

SW

1V/DIV

0V

V

IN

= 1.3V

V

OUT

= 3.3V

I

OUT

= 50mA

L = 6.8µH

C

OUT

= 4.7µF

100ns/DIV

3400 G07

V

OUT(AC)

100mV/DIV

I

OUT

60mA

10µA

V

IN

= 1.3V

V

OUT

= 3.3V

10ms/DIV

I

OUT

= 60mA TO 10µA

L = 6.8µH

C

OUT

= 4.7µF

3400 G08

V

OUT(AC)

100mV/DIV

I

OUT

100mA

40mA

V

IN

= 1.3V

V

OUT

= 3.3V

100µs/DIV

I

OUT

= 40mA TO 100mA

L = 6.8µH

C

OUT

= 4.7µF

3400 G09

34001f

3

LTC3400-1

U U U

PI FU CTIO S

SW (Pin 1): Switch Pin. Connect inductor between SW and V

IN

. Optional Schottky diode is connected between

SW and V

OUT

. Keep these PCB trace lengths as short and wide as possible to reduce EMI and voltage overshoot. If the inductor current falls to zero, or SHDN is low, an internal 100Ω antiringing switch is connected from SW to

V

IN

to minimize EMI.

GND (Pin 2): Signal and Power Ground. Provide a short direct PCB path between GND and the (–) side of the output capacitor(s).

FB (Pin 3): Feedback Input to the g m

Error Amplifier.

Connect resistor divider tap to this pin. The output voltage can be adjusted from 2.5V to 5V by:

V

OUT

= 1.23V • [1 + (R1/R2)]

SHDN (Pin 4): Logic Controlled Shutdown Input.

SHDN = High: Normal free running operation, 1.2MHz

typical operating frequency.

SHDN = Low: Shutdown, quiescent current < 1µA.

100Ω connected between SW and V

IN

. V

IN

is connected to V

OUT

through the internal P-channel MOSFET synchronous rectifier and external inductor.

Typically, SHDN should be connected to V

IN

through a 1M pull-up resistor.

V

OUT

(Pin 5): Output Voltage Sense Input and Drain of the

Internal Synchronous Rectifier MOSFET. Bias is derived from V

OUT

. PCB trace length from V

OUT

to the output filter capacitor(s) should be as short and wide as possible. V

OUT is connected to V

IN

in shutdown through the internal

P-channel MOSFET synchronous rectifier.

V

IN

(Pin 6): Battery Input Voltage. The device gets its start-up bias from V

IN

. Once V

OUT

exceeds V

IN

, bias comes from V

OUT

. Thus, once started, operation is completely independent from V

IN

. Operation is only limited by the output power level and the battery’s internal series resistance.

BLOCK DIAGRA

W

+

SINGLE

CELL

INPUT

6

V

IN

START-UP

OSC

C

IN

1µF

A

B

A/B

MUX

L1

4.7µH

V

OUT

GOOD

–

+

2.3V

1

SW

0.45Ω

OPTIONAL

SCHOTTKY

V

OUT

5

3.3V

OUTPUT

RAMP

GEN

1.2MHz

PWM

CONTROL

SLOPE

COMP

SHUTDOWN

SYNC

DRIVE

CONTROL

Σ

0.35Ω

CURRENT

SENSE

C

FF

(OPTIONAL)

R1

1.02M

1%

(EXTERNAL)

PWM

COMPARATOR

–

–

+ g m

ERROR

AMP

+

–

FB

3

C

OUT

4.7µF

SHDN

4

SLEEP

Burst Mode

OPERATION

CONTROL

SHUTDOWN

CONTROL

R

C

80k

C

C

150pF

C

P2

2.5pF

SHUTDOWN

2 GND

1.23V

REF

R2

604k

1%

(EXTERNAL)

34001 BD

34001f

4

LTC3400-1

OPERATIO

U

The LTC3400-1 is a1.2MHz, synchronous boost converter housed in a 6-lead ThinSOT package. Able to operate from an input voltage below 1V, the device features fixed frequency, current mode PWM control for exceptional line and load regulation. With its low R

DS(ON)

and gate charge internal MOSFET switches, the device maintains high efficiency over a wide range of load current. Detailed descriptions of the three distinct operating modes follow.

Operation can be best understood by referring to the Block

Diagram.

Low Voltage Start-Up

The LTC3400-1 will start up at a typical V

IN

voltage of

0.85V or higher. The low voltage start-up circuitry controls the internal NMOS switch up to a maximum peak inductor current of 850mA (typ), with an approximate 1.5µs offtime during start-up, allowing the device to start up into an output load. Once V

OUT

exceeds 2.3V, the start-up circuitry is disabled and normal fixed frequency PWM operation is initiated. In this mode, the LTC3400-1 operates independent of V

IN

, allowing extended operating time as the battery can droop to several tenths of a volt without affecting output voltage regulation. The limiting factor for the application becomes the ability of the battery to supply sufficient energy to the output.

Low Noise Fixed Frequency Operation

Oscillator: The frequency of operation is internally set to

1.2MHz.

Error Amp: The error amplifier is an internally compensated transconductance type (current output) with a transconductance (g m

) = 33 microsiemens. The internal 1.23V reference voltage is compared to the voltage at the FB pin to generate an error signal at the output of the error amplifier. A voltage divider from V

OUT

to ground programs the output voltage via FB from 2.5V to 5V using the equation:

V

OUT

= 1.23V • [1 + (R1/R2)]

Current Sensing: A signal representing NMOS switch current is summed with the slope compensator. The summed signal is compared to the error amplifier output to provide a peak current control command for the PWM.

Peak switch current is limited to approximately 850mA independent of input or output voltage. The current signal is blanked for 40ns to enhance noise rejection.

Zero Current Comparator: The zero current comparator monitors the inductor current to the output and shuts off the synchronous rectifier once this current reduces to approximately 20mA. This prevents the inductor current from reversing in polarity improving efficiency at light loads.

Antiringing Control: The antiringing control circuitry prevents high frequency ringing of the SW pin as the inductor current goes to zero by damping the resonant circuit formed by L and C

SW

(capacitance on SW pin).

Burst Mode Operation

Portable devices frequently spend extended time in low power or standby mode, only switching to high power drain when specific functions are enabled. In order to improve battery life in these types of products, high power converter efficiency needs to be maintained over a wide output power range. In addition to its high efficiency at moderate and heavy loads, the LTC3400-1 includes automatic Burst Mode operation that improves efficiency of the power converter at light loads. Burst mode operation is initiated if the output load current falls below an internally programmed threshold (see Typical Performance graph, Output Load Burst Mode Threshold vs V

IN

).

Once initiated, the Burst Mode operation circuitry shuts down most of the device, only keeping alive the circuitry required to monitor the output voltage. This is referred to as the sleep state. In sleep, the LTC3400-1 draws only

19µA from the output capacitor, greatly enhancing efficiency. When the output voltage has drooped approximately 1% from nominal, the LTC3400-1 wakes up and commences normal PWM operation. The output capacitor recharges and causes the LTC3400-1 to reenter sleep if the output load remains less than the sleep threshold. The frequency of this intermittent PWM or burst operation is proportional to load current; that is, as the load current drops further below the burst threshold, the LTC3400-1 turns on less frequently. When the load current increases

34001f

5

LTC3400-1

OPERATIO

U

above the burst threshold, the LTC3400-1 will resume continuous PWM operation seamlessly. Referring to the

Block Diagram, an optional capacitor (C

FF

) between V

OUT and FB in some circumstances can reduce the peak-topeak V

OUT

ripple and input quiescent current during Burst

Mode operation. Typical values for C

FF

range from 15pF to

220pF.

U U W

APPLICATIO S I FOR ATIO

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PCB LAYOUT GUIDELINES

The high speed operation of the LTC3400-1 demands careful attention to board layout. You will not get advertised performance with careless layout. Figure 1 shows the recommended component placement. A large ground pin copper area will help to lower the chip temperature. A multilayer board with a separate ground plane is ideal, but not absolutely necessary.

will allow greater output current capability by reducing the inductor ripple current. Increasing the inductance above

10µH will increase size while providing little improvement in output current capability.

The approximate output current capability of the LTC3400-1 versus inductance value is given in the equation below and illustrated graphically in Figure 2.

V

IN

1 SW V

IN

6

2 GND V

OUT

5

3 FB SHDN 4

(OPTIONAL)

SHDN

V

OUT

34001 F02

RECOMMENDED COMPONENT PLACEMENT. TRACES

CARRYING HIGH CURRENT ARE DIRECT. TRACE AREA AT

FB PIN IS SMALL. LEAD LENGTH TO BATTERY IS SHORT

180

V

IN

=1.2V

160

140

120

110

V

OUT

= 3V

V

OUT

= 3.3V

V

OUT

= 3.6V

V

OUT

= 5V

80

60

3 5 7 9 11 13 15 17 19

INDUCTANCE (µH)

21 23

34001 F03

Figure 2. Maximum Output Current vs

Inductance Based On 90% Efficiency

Figure 1. Recommended Component Placement for Single Layer Board

COMPONENT SELECTION

Inductor Selection

The LTC3400-1 can utilize small surface mount and chip inductors due to its fast 1.2MHz switching frequency. A minimum inductance value of 3.3µH is necessary for 3.6V

and lower voltage applications and 4.7µH for output voltages greater than 3.6V. Larger values of inductance

I

OUT MAX )

= η

•

⎛

I

P

–

V

IN

• D

2

⎞

⎠

•

(

1 – D

) where:

η = estimated efficiency

I

P

= peak current limit value (0.6A)

V

IN

= input (battery) voltage

D = steady-state duty ratio = (V

OUT

– V

IN

)/V

OUT f = switching frequency (1.2MHz typical)

L = inductance value

34001f

6

LTC3400-1

U U W

APPLICATIO S I FOR ATIO

U

The inductor current ripple is typically set for 20% to 40% of the maximum inductor current (I

P

). High frequency ferrite core inductor materials reduce frequency dependent power losses compared to cheaper powdered iron types, improving efficiency. The inductor should have low

ESR (series resistance of the windings) to reduce the I

2

R power losses, and must be able to handle the peak inductor current without saturating. Molded chokes and some chip inductors usually do not have enough core to support the peak inductor currents of 850mA seen on the

LTC3400-1. To minimize radiated noise, use a toroid, pot core or shielded bobbin inductor. See Table 1 for some suggested components and suppliers.

Table 1. Recommended Inductors

PART

L

(µH)

CDRH5D18-4R1

CDRH5D18-100

CDRH3D16-4R7

CDRH3D16-6R8

4.1

10

4.7

CR43-4R7

CR43-100

4.7

10

CMD4D06-4R7MC 4.7

CMD4D06-3R3MC 3.3

DS1608-472

DS1608-103

DO1608C-472

D52LC-4R7M

D52LC-100M

4.7

10

4.7

4.7

10

60

75

90

84

137

MAX

DCR

mΩ

57

124

105

170

109

182

216

174

HEIGHT

(mm)

3.5

3.5

0.8

0.8

2.0

2.0

1.8

1.8

2.9

2.9

2.9

2.0

2.0

LQH3C4R7M24 4.7

195 2.2

VENDOR

Sumida

(847) 956-0666 www.sumida.com

Coilcraft

(847) 639-6400 www.coilcraft.com

Toko

(408) 432-8282 www.tokoam.com

Murata www.murata.com

Output and Input Capacitor Selection

Low ESR (equivalent series resistance) capacitors should be used to minimize the output voltage ripple. Multilayer ceramic capacitors are an excellent choice as they have extremely low ESR and are available in small footprints. A

2.2µF to 10µF output capacitor is sufficient for most applications. Larger values up to 22µF may be used to obtain extremely low output voltage ripple and improve transient response. An additional phase lead capacitor may be required with output capacitors larger than 10µF to maintain acceptable phase margin. X5R and X7R dielectric materials are preferred for their ability to maintain capacitance over wide voltage and temperature ranges.

Low ESR input capacitors reduce input switching noise and reduce the peak current drawn from the battery. It follows that ceramic capacitors are also a good choice for input decoupling and should be located as close as possible to the device. A 4.7µF input capacitor is sufficient for virtually any application. Larger values may be used without limitations. Table 2 shows a list of several ceramic capacitor manufacturers. Consult the manufacturers directly for detailed information on their entire selection of ceramic parts.

Table 2. Capacitor Vendor Information

SUPPLIER

AVX

Murata

Taiyo Yuden

PHONE

(803) 448-9411

(714) 852-2001

(408) 573-4150

WEBSITE

www.avxcorp.com

www.murata.com

www.t-yuden.com

Output Diode

Use a Schottky diode such as an MBR0520L, PMEG2010EA,

1N5817 or equivalent if the converter output voltage is 4.5V

or greater. The Schottky diode carries the output current for the time it takes for the synchronous rectifier to turn on. Do not use ordinary rectifier diodes, since the slow recovery times will compromise efficiency. A Schottky diode is also strongly recommended for output voltages below 4.5V, and will increase converter efficiency by 2% to 3%.

34001f

7

LTC3400-1

U

TYPICAL APPLICATIO S

Single Cell to 3.3V Synchronous Boost Converter with Load Disconnect in Shutdown

+

SINGLE

AA CELL

OFF ON

C1

4.7µF

L1

4.7µH

D1

6

1

V

IN

SW

V

OUT

5

4

LTC3400-1

SHDN FB

3

GND

2

D1: PHILLIPS PMEG2010EA

L1: SUMIDA CDRH2D18/HP-4R7

R3

510k

R3

510k

C2

4.7µF

M1

Si2305DS

Q1

2N3904

R1

1.02M

1%

V

OUT

3.3V

100mA

R2

604k

1%

34001 TA01a

8

34001f

U

TYPICAL APPLICATIO S

Single Lithium Cell to 5V, 250mA

2Ω

1nF

L1

4.7µH

+

LITHIUM

CELL

C1

4.7µF

6

V

IN

1

SW

V

OUT

5

OFF ON

LTC3400-1

4

SHDN

GND

2

FB

D1: PHILIPS PMEG2010EA

L1: SUMIDA CDRH2D18/HP-4R7

C1, C2: TAIYO YUDEN JMK212BJ475MG

3

D1

C2

4.7µF

R1

1.02M

1%

R2

332k

1%

34001 TA02a

OPTIONAL

SNUBBER

C3

100pF

LTC3400-1

3.6V to 5V Efficiency

100

90

LTC3400-1

C

O

= 4.7µF

L = 4.7µH

80

70

60

50

0.1

1 10

LOAD CURRENT (mA)

100 1000

34001 TA02b

34001f

9

LTC3400-1

U

TYPICAL APPLICATIO S

Single Cell AA Cell to ±3V Synchronous Boost Converter

+

SINGLE

AA CELL

C1

4.7µF

OFF ON

L1

4.7µH

6

V

IN

1

SW

V

OUT

5

LTC3400-1

4

SHDN

GND

2

FB

3

C3

1µF

R1

1.02M

1%

R2

715k

1%

D1, D2: ZETEX FMND7000 DUAL DIODE

L1: SUMIDA CDRH2D18/HP-4R7

D1 D2

C2

4.7µF

V

OUT1

3V

90mA

C4

10µF

34001 TA03a

V

OUT2

–3V

10mA

10

34001f

PACKAGE DESCRIPTIO

U

S6 Package

6-Lead Plastic TSOT-23

(Reference LTC DWG # 05-08-1636)

3.85 MAX 2.62 REF

0.62

MAX

0.95

REF

1.22 REF

1.4 MIN

2.80 BSC

1.50 – 1.75

(NOTE 4)

2.90 BSC

(NOTE 4)

PIN ONE ID

LTC3400-1

RECOMMENDED SOLDER PAD LAYOUT

PER IPC CALCULATOR

0.20 BSC

DATUM ‘A’

0.30 – 0.50 REF

0.09 – 0.20

(NOTE 3)

NOTE:

1. DIMENSIONS ARE IN MILLIMETERS

2. DRAWING NOT TO SCALE

3. DIMENSIONS ARE INCLUSIVE OF PLATING

4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR

5. MOLD FLASH SHALL NOT EXCEED 0.254mm

6. JEDEC PACKAGE REFERENCE IS MO-193

1.00 MAX

0.95 BSC

0.80 – 0.90

1.90 BSC

0.30 – 0.45

6 PLCS (NOTE 3)

0.01 – 0.10

S6 TSOT-23 0302

Information furnished by Linear Technology Corporation is believed to be accurate and reliable.

However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.

34001f

11

LTC3400-1

TYPICAL APPLICATIO

U

Single AA Cell to 2.5V Synchronous Boost Converter

L1

3.3µH

D1

+

SINGLE

AA CELL

C1

4.7µF

6

V

IN

1

SW

V

OUT

5

OFF ON

D1: PHILIPS PMEG2010EA

L1: SUMIDA CDRH2D18/HP-3R7

4

LTC3400-1

SHDN

GND

FB

3

2

R1

1.02M

1%

R2

1M

1%

34001 TA04a

V

OUT

2.5V

130mA

C2

4.7µF

RELATED PARTS

PART NUMBER

LT1308A/LT1308B

LT1613

LT1615

LT

®

1618

LT1619

LTC1872

LT1930/LT1930A

LT1932

LT1946/LT1946A

LT1949

DESCRIPTION

High Efficiency Boost DC/DC Controller

ThinSOT Boost DC/DC Controller

COMMENTS

High Current, Micropower, Single Cell 600kHz DC/DC Converter 5V at 1A with Single Li-Ion Cell, V

OUT

to 34V

1.4MHz, Single Cell DC/DC Converter in ThinSOT V

IN

as Low as 1.1V, 3V at 30mA from Single Cell

Micropower Step-Up DC/DC Converter in ThinSOT

1.4MHz Step-Up DC/DC Converter with Current Limit

I

Q

= 20µA, 1µA Shutdown Current, V

IN

as Low as 1V

1.5A Switch, 1.6V to 18V Input Range,

Input or Output Current Limiting

1A Gate Drive, 1.1V to 20V Input, Separate V

CC

for Gate Drive

50kHz, 2.5V to 9.8V Input

1.2MHz/2.2MHz DC/DC Converters in ThinSOT

Constant Current Step-Up LED Driver

1.2MHz/2.7MHz Boost DC/DC Converters

600kHz, 1A Switch PWM DC/DC Converter

V

IN

= 2.6V to 16V, 5V at 450mA from 3.3V Input

Drives Up to Eight White LEDs, ThinSOT Package

1.5A, 36V Internal Switch, 8-Pin MSOP Package

1A, 0.5Ω, 30V Internal Switch, V

IN

as Low as 1.5V,

Low-Battery Detect Active in Shutdown

LTC3400/LTC3400B 600mA, 1.2MHz Synchronous Boost Converters in ThinSOT

LTC3401

LTC3402

LTC3421

LTC3423

LTC3424

LTC3425

LTC3429

1A, 3MHz Micropower Synchronous Boost Converter

2A, 3MHz Micropower Synchronous Boost Converter

3A, 3MHz Micropower Synchronous Boost Converter

1A, 3MHz Micropower Synchronous Boost Converter

2A, 3MHz Micropower Synchronous Boost Converter

5A, 8MHz, 4-Phase Micropower Synchronous Boost Converter

600mA, 500kHz Synchronous Boost Converter in ThinSOT

Up to 92% EFFiciency, 600mA Switch,

No Burst Option (LTC3400B)

1A Switch, Programmable Frequency, 10-Pin MSOP Package

2A Switch, Programmable Frequency, 10-Pin MSOP Package

Up to 96% Efficiency, 3A Switch, True Output Disconnect,

4mm x 4mm QFN Package

1A Switch, Separate Bias Pin for Low Output Voltages

2A Switch, Separate Bias Pin for Low Output Voltages

Up to 95% Efficiency, 5A Switch, True Output

Disconnect, I

Q

= 12µA, QFN Package

Up to 96% Efficiency, 600mA Switch, True Output

Disconnect, Soft Start

12

Linear Technology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

(408) 432-1900

●

FAX: (408) 434-0507

●

www.linear.com

34001f

LT/TP 0604 1K • PRINTED IN USA

© LINEAR TECHNOLOGY CORPORATION 2004