MAX1598 DS - Mouser Electronics

19-2584; Rev 0; 10/02

Low-Noise, Low-Dropout, 200mA

Linear Regulator

General Description

The MAX1598 low-noise, low-dropout linear regulator operates from a 2.5V to 6.5V input and delivers up to

200mA. Typical output noise is 30µV

RMS

, and typical dropout is only 236mV at 200mA. The output voltage is preset to voltages from 2.5V to 5V in 100mV increments.

Designed with an internal P-channel MOSFET pass transistor, the MAX1598 maintains a low 100µA supply current independent of the load current and dropout voltage. Other features include a 10nA logic-controlled shutdown mode, short-circuit and thermal-shutdown protection, and reverse battery protection. The device also includes an autodischarge function, which actively discharges the output voltage to ground when the device is placed in shutdown. The MAX1598 comes in a thin 5-pin SOT23 package.

Features

200mA Output Current

Low Output Noise: 30µV

RMS

Low 55mV Dropout at 50mA Output

Low 85µA No-Load Supply Current

Low 100µA Operating Supply Current,

Even in Dropout

Thermal-Overload and Short-Circuit Protection

Reverse Battery Protection

Output Current Limit

Preset Output Voltages

10nA Logic-Controlled Shutdown

Applications

Cellular, Cordless, and PCS Phones

PCMCIA Cards

Modems

Hand-Held Instruments

Palmtop Computers

Electronic Planners

Ordering Information

PART

MAX1598EZKxy-T*

TEMP RANGE PIN-PACKAGE

-40

°C to +85°C Thin SOT23-5

*xy is the output voltage code (see the Selector Guide at end of

data sheet).

Typical Operating Circuit

INPUT

2.5V TO 6.5V

C

IN

1

µF

IN

MAX1598

OUT

C

OUT

2.2

µF

ON

OFF

SHDN

C

BP

0.01

µF

BP

GND

OUTPUT

PRESET

2.5V TO 5V

200mA

TOP VIEW

Pin Configuration

IN 1

GND

2

MAX1598

5 OUT

SHDN

3

THIN SOT23-5

4 BP

________________________________________________________________ Maxim Integrated Products 1

For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

Low-Noise, Low-Dropout, 200mA

Linear Regulator

ABSOLUTE MAXIMUM RATINGS

IN to GND ....................................................................-7V to +7V

Output Short-Circuit Duration ............................................Infinite

SHDN to GND..............................................................-7V to +7V

SHDN to IN ...............................................................-7V to +0.3V

OUT, BP to GND ..........................................-0.3V to (V

IN

+ 0.3V)

Continuous Power Dissipation (T

A

= +70°C)

5-Pin Thin SOT23 (derate 9.1mW/°C above +70°C) ....727mW

Operating Temperature Range ...........................-40°C to +85°C

Junction Temperature ......................................................+150°C

θ

JB

(thin).........................................................................110°C/W

Storage Temperature.........................................-65°C to +150°C

Lead Temperature (soldering, 10s) .................................+300°C

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

ELECTRICAL CHARACTERISTICS

(V

IN

= (V

OUT(NOMINAL)

+ 0.5V) or 2.5V (whichever is greater), T

A

= -40°C to +85°C, unless otherwise noted. Typical values are at T

A

=

+25°C.) (Note 1)

PARAMETER

Input Voltage

SYMBOL

V

IN

CONDITIONS MIN

2.5

-1.4

TYP

Output Voltage Accuracy

I

OUT

= 0.1mA, T

A

= +25°C, V

OUT

≥ 2.5V

I

OU T

= 0.1m A to 120m A, T

A

= - 40° C to + 85°C ,

V

OUT

≥ 2.5V

-3

MAX UNITS

6.5

V

+1.4

%

+2

Maximum Output Current

Current Limit I

LIM

200

220 mA mA

Ground-Pin Current

Dropout Voltage (Note 2)

Line Regulation

Load Regulation

Output Voltage Noise

I

Q

∆V

LNR

∆V

LDR e n

No load

I

OUT

= 150mA

I

OUT

= 1mA

I

OUT

= 50mA

I

OUT

= 200mA

V

IN

= 2.5V or (V

OUT

+ 0.1V) to 6.5V,

I

OUT

= 1mA

I

OUT

= 0.1mA to 120mA, C

OUT

= 1µF f = 10Hz to 100kHz,

C

BP

= 0.01µF

C

OUT

= 10µF

C

OUT

= 100µF

-0.15

458

85

100

1.1

55

236

0

0.01

30

20

180

120

+0.15

0.04

µA mV

%/V

%/mA

µV

RMS

SHUTDOWN

SHDN Input Threshold

V

IH

V

IL

V

IN

= 2.5V to 5.5V

V

IN

= 2.5V to 5.5V

2.0

0.4

1

V

SHDN Input Bias Current

Shutdown Supply Current

Shutdown Exit Delay

I

SHDN

V

SHDN

= V

IN

I

Q(SHDN)

V

OUT

= 0V

C

BP

= 0.1µF

C

OUT

= 1µF, no load

(Note 3)

T

A

= +25°C

T

A

= +85°C

T

A

= +25°C

T

A

= +85°C

T

A

= +25°C

T

A

= -40°C to +85°C

0.01

0.5

0.01

0.2

30

1

150

300

µA

µA

µs

Resistance Shutdown Discharge 300

2 _______________________________________________________________________________________

Low-Noise, Low-Dropout, 200mA

Linear Regulator

ELECTRICAL CHARACTERISTICS (continued)

(V

IN

= (V

OUT(NOMINAL)

+ 0.5V) or 2.5V (whichever is greater), T

A

= -40°C to +85°C, unless otherwise noted. Typical values are at T

A

=

+25°C.) (Note 1)

PARAMETER

THERMAL PROTECTION

Thermal-Shutdown Temperature

Thermal-Shutdown Hysteresis

SYMBOL

T

SHDN

∆T

SHDN

CONDITIONS MIN TYP

155

15

MAX UNITS

Note 1: Limits are 100% production tested at T

A

= +25°C. Limits over the operating temperature range are guaranteed through correlation using guaranteed by design (GBD) methods.

Note 2: The dropout voltage is defined as V

IN

- V

OUT

, when V

OUT is 100mV below the value of V

OUT for V

IN

= V

OUT

+ 0.5V.

Note 3: Time needed for V

OUT to reach 95% of final value.

°C

°C

__________________________________________Typical Operating Characteristics

(V

IN

= (V

OUT(NOMINAL)

+ 0.5V) or 2.5V (whichever is greater), C

IN

= 1µF, C

OUT

= 2.2µF, C

BP

= 0.01µF, T

A

= +25°C, unless otherwise noted.)

OUTPUT VOLTAGE vs. LOAD CURRENT

(MAX1598EZK25)

OUTPUT VOLTAGE vs. LOAD CURRENT

(MAX1598EZK50)

GROUND-PIN CURRENT vs. LOAD CURRENT

2.60

2.55

2.50

2.45

2.40

5.2

5.1

5.0

4.9

4.8

110

105

100

95

90

85

80

75

70

65

60

MAX1598EZK25

MAX1598EZK50

0 50 100

LOAD CURRENT (mA)

150 200 0 50 100

LOAD CURRENT (mA)

150 200 0 50 100

LOAD CURRENT (mA)

150 200

120

GROUND-PIN CURRENT vs. INPUT VOLTAGE

(MAX1598EZK25)

I

LOAD

= 50mA

100

120

GROUND-PIN CURRENT vs. INPUT VOLTAGE

(MAX1598EZK50)

I

LOAD

= 50mA

100

6

5

OUTPUT VOLTAGE vs. INPUT VOLTAGE

NO LOAD

MAX1598EZK50

80

80 4

NO LOAD

NO LOAD

60

60 3

40

20

0

0 1 2 3 4

INPUT VOLTAGE (V)

5 6

40

20

0

0 1 2 3 4

INPUT VOLTAGE (V)

5 6

2

1

0

0 1

MAX1598EZK25

2 3 4

INPUT VOLTAGE (V)

5 6

_______________________________________________________________________________________

3

Low-Noise, Low-Dropout, 200mA

Linear Regulator

Typical Operating Characteristics (continued)

(V

IN

= (V

OUT(NOMINAL)

+ 0.5V) or 2.5V (whichever is greater), C

IN

= 1µF, C

OUT

= 2.2µF, C

BP

= 0.01µF, T

A

= +25°C, unless otherwise noted.)

2.60

OUTPUT VOLTAGE vs. TEMPERATURE

(MAX1598EZK25)

I

LOAD

= 50mA

2.55

2.50

2.45

2.40

-40 -20 0 20 40

TEMPERATURE (

°C)

60 80 100

DROPOUT VOLTAGE vs. LOAD CURRENT

(MAX1598EZK25)

300

T

A

= +25

°C

250

200

T

A

= +85

°C

150

100

T

A

= -40

°C

50

0

0

10

40 60 120

LOAD CURRENT (mA)

160

OUTPUT NOISE SPECTRAL DENSITY vs. FREQUENCY

C

BP

= 0.01

µF

I

LOAD

= 10mA

200

1

0.1

0.01

0

C

OUT

= 1

µF

C

OUT

= 10

µF

1 10

FREQUENCY (kHz)

100 1000

5.2

OUTPUT VOLTAGE vs. TEMPERATURE

(MAX1598EZK50)

I

LOAD

= 50mA

5.1

5.0

4.9

4.8

-40 -20 0 20 40

TEMPERATURE (

°C)

60 80 100

DROPOUT VOLTAGE vs. LOAD CURRENT

(MAX1598EZK50)

300

250

200

150

100

50

0

0

T

A

= +85

°C

T

A

= +25

°C

T

A

= -40

°C

40 80 120

LOAD CURRENT (mA)

160 200

OUTPUT NOISE vs. BP CAPACITANCE

60

50

40

30

80

70

20

10

0

0.001

C

OUT

= 10

µF

I

LOAD

= 10mA f = 10Hz to 100kHz

MAX1598EZK50

MAX1598EZK30

MAX1598EZK25

0.01

BP CAPACITANCE (

µF)

0.1

60

50

40

30

20

GROUND-PIN CURRENT vs. TEMPERATURE

200

180

160

140

120

100

80

60

40

20

0

-40 -20

MAX1598EZK50

0 20

I

LOAD

= 50mA

MAX1598EZK25

40 60 80 100

TEMPERATURE (

°C)

POWER-SUPPLY REJECTION RATIO vs. FREQUENCY

70

C

OUT

= 10

µF

C

OUT

= 1

µF

10

0

0.01

I

LOAD

C

BP

= 50mA

= 0.1

µF

0.1

1 10

FREQUENCY (kHz)

100 1000

OUTPUT NOISE vs. LOAD CURRENT

60

50

40

30

MAX1598EZK50

MAX1598EZK30

20

MAX1598EZK25

10

0

1

C

C

OUT

BP

= 10

µF

= 0.01

µF f = 10Hz to 100kHz

10 100

LOAD CURRENT (mA)

1000

4 _______________________________________________________________________________________

Low-Noise, Low-Dropout, 200mA

Linear Regulator

Typical Operating Characteristics (continued)

(V

IN

= (V

OUT(NOMINAL)

+ 0.5V) or 2.5V (whichever is greater), C

IN

= 1µF, C

OUT

= 2.2µF, C

BP

= 0.01µF, T

A

= +25°C, unless otherwise noted.)

OUTPUT NOISE 10Hz TO 100kHz

REGION OF STABLE C

OUT

ESR vs. LOAD CURRENT

100

V

OUT

50

µV/div

10

C

OUT

= 10

µF

1

0.1

STABLE REGION

C

OUT

= 2.2

µF

4V

3V

1ms/div

MAX1598EZK25, C

OUT

= 10

µF, I

LOAD

= 10mA, C

BP

= 0.1

µF

LINE-TRANSIENT RESPONSE

MAX1598-18

V

IN

3.01V

3.00V

2.99V

0.01

0 50 100

LOAD CURRENT (mA)

150 200

LOAD-TRANSIENT RESPONSE

NEAR DROPOUT

MAX1598-20

LOAD-TRANSIENT RESPONSE

MAX1598-19

V

OUT

3.01V

3.00V

2.99V

V

OUT

3.001V

3.000V

2.999V

100

µs/div

MAX1598EZK30, I

LOAD

= 50mA

MAX1598EZK25

SHUTDOWN EXIT DELAY

MAX1598-21

V

OUT

50mA

10

µs/div

MAX1598EZK30, V

C

IN

= 10

µF, I

LOAD

IN

= V

OUT

+ 0.5V,

= 0 TO 50mA

MAX1598EZK50

SHUTDOWN EXIT DELAY

MAX1598-22

I

LOAD

50mA

10

µs/div

MAX1598EZK30, V

C

IN

= 10

µF, I

LOAD

IN

= V

OUT

+ 0.1V,

= 0 TO 50mA

ENTERING SHUTDOWN

MAX1598-23

I

LOAD

V

SHDN

2V

0V

2V

1V

0V

C

BP

= 0.01

µF

C

BP

= 0.1

µF

V

SHDN

2V

0V

V

OUT

4V

2V

0V

C

BP

= 0.01

µF

C

BP

= 0.1

µF

V

SHDN

2V

0V

5V

V

OUT

0V

V

OUT

I

5

µs/div

LOAD

= 50mA

5

µs/div

I

LOAD

= 50mA

500

µs/div

NO LOAD

_______________________________________________________________________________________

5

Low-Noise, Low-Dropout, 200mA

Linear Regulator

______________________________________________________________Pin Description

PIN

1

2

3

4

5

NAME

IN

GND

SHDN

BP

OUT

FUNCTION

Regulator Input. Supply voltage can range from 2.5V to 6.5V. Bypass with a 1µF capacitor to GND

(see the Capacitor Selection and Regulator Stability section).

Ground. This pin also functions as a heatsink. Solder to a large pad or the circuit-board ground plane to maximize power dissipation.

Active-Low Shutdown Input. A logic low reduces the supply current to 10nA and causes the output voltage to discharge to GND. Connect to IN for normal operation.

Reference-Noise Bypass. Bypass with a low-leakage, 0.01µF ceramic capacitor for reduced noise at the output.

Regulator Output. Sources up to 200mA. Bypass with a 2.2µF (<0.2

Ω typical ESR) capacitor to GND.

Detailed Description

The MAX1598 is a low-noise, low-dropout, low-quiescent-current linear regulator designed primarily for battery-powered applications. The part is available with preset output voltages from 2.5V to 5V in 100mV increments. This device can supply loads up to 200mA. As illustrated in Figure 1, the MAX1598 consists of a 1.25V

reference, error amplifier, P-channel pass transistor, and internal feedback voltage-divider.

The 1.25V bandgap reference is connected to the error amplifier’s inverting input. The error amplifier compares this reference with the feedback voltage and amplifies the difference. If the feedback voltage is lower than the reference voltage, the pass-transistor gate is pulled lower, which allows more current to pass to the output and increases the output voltage. If the feedback voltage is too high, the pass-transistor gate is pulled up, allowing less current to pass to the output. The output voltage is fed back through an internal resistor voltagedivider connected to the OUT pin.

An external bypass capacitor connected to the BP pin reduces noise at the output. Additional blocks include a current limiter, reverse battery protection, thermal sensor, and shutdown logic. The MAX1598 also includes an autodischarge function, which actively discharges the output voltage to ground when the device is placed in shutdown mode.

IN

SHDN

REVERSE

BATTERY

PROTECTION

MAX1598

SHUTDOWN

AND

POWER-ON

CONTROL

ERROR

AMP

MOS DRIVER

WITH I

LIMIT

P

OUT

N

THERMAL

SENSOR

1.25V

REF

GND

Figure 1. Functional Diagram

6 _______________________________________________________________________________________

BP

Low-Noise, Low-Dropout, 200mA

Linear Regulator

Output Voltage

The MAX1598 is supplied with factory-set output voltages from 2.5V to 5V in 100mV increments. Except for the

MAX1598EZK29 and the MAX1598EZK32 (which have an output voltage preset at 2.84V and 3.15V, respectively), the two-digit suffix allows the customer to choose the output voltage in 100mV increments. For example, the

MAX1598EZK33 has a preset output voltage of 3.3V (see the Selector Guide).

Internal P-Channel Pass Transistor

The MAX1598 features a 1.1

Ω typical P-channel MOSFET pass transistor. This provides several advantages over similar designs using PNP pass transistors, including longer battery life. The P-channel MOSFET requires no base drive, which reduces quiescent current considerably. PNP-based regulators waste considerable current in dropout when the pass transistor saturates. They also use high base-drive currents under large loads. The

MAX1598 does not suffer these problems and consumes only 100µA of quiescent current whether in dropout, lightload, or heavy-load applications (see the Typical

Operating Characteristics).

Current Limit

The MAX1598 includes a current limiter, which monitors and controls the pass transistor’s gate voltage, limiting the output current to 458mA. For design purposes, consider the current limit to be 220mA minimum to 1.1A maximum.

The output can be shorted to ground indefinitely without damaging the part.

Thermal-Overload Protection

Thermal-overload protection limits total power dissipation in the MAX1598. When the junction temperature exceeds T

J

= +155°C, the thermal sensor signals the shutdown logic, turning off the pass transistor and allowing the IC to cool. The thermal sensor turns the pass transistor on again after the IC’s junction temperature cools by 15°C, resulting in a pulsed output during continuous thermal-overload conditions.

Thermal-overload protection is designed to protect the

MAX1598 in the event of fault conditions. For continual operation, do not exceed the absolute maximum junction-temperature rating of T

J

= +150°C.

Operating Region and Power Dissipation

The MAX1598 maximum power dissipation depends on the thermal resistance of the case and circuit board, the temperature difference between the die junction and ambient air, and the rate of air flow. The power dissipation across the device is P = I

OUT

(V

IN

- V

OUT

). The maximum power dissipation is:

P

MAX

= (T

J

- T

A

) / (

θ

JB

+

θ

BA

) where T

J

- T

A is the temperature difference between the

MAX1598 die junction and the surrounding air,

θ

JB

(or

θ

JC

) is the thermal resistance of the package, and

θ

BA is the thermal resistance through the PC board, copper traces, and other materials to the surrounding air.

The GND pin of the MAX1598 performs the dual functions of providing an electrical connection to ground and channeling heat away. Connect the GND pin to ground using a large pad or ground plane.

Reverse Battery Protection

The MAX1598 has a unique protection scheme that limits the reverse supply current to 1mA when either V

IN or

V

SHDN falls below ground. Their circuitry monitors the polarity of these two pins and disconnects the internal circuitry and parasitic diodes when the battery is reversed. This feature prevents device damage.

Noise Reduction

An external 0.01µF bypass capacitor at BP, in conjunction with an internal 200k

Ω resistor, creates an 80Hz lowpass filter for noise reduction. The MAX1598 exhibits

30µV

RMS of output voltage noise with C

BP

= 0.01µF and

C

OUT

= 10µF. This is negligible in most applications.

Startup time is minimized by a power-on circuit that precharges the bypass capacitor. The Typical Operating

Characteristics section shows graphs of Noise vs. BP

Capacitance, Noise vs. Load Current, and Output Noise

Spectral Density.

____________Applications Information

Capacitor Selection and

Regulator Stability

Under normal conditions, use a 1µF capacitor on the

MAX1598 input and a 2.2µF to 10µF capacitor on the output. Larger input capacitor values and lower ESRs provide better supply-noise rejection and line-transient response. Reduce noise and improve load-transient response, stability, and power-supply rejection by using large output capacitors. For stable operation over the full temperature range and with load currents up to 200mA, a

2.2µF (min) ceramic capacitor is recommended.

Note that some ceramic dielectrics exhibit large capacitance and ESR variation with temperature. With dielectrics such as Z5U and Y5V, it may be necessary to increase the capacitance by a factor of 2 or more to ensure stability at temperatures below -10°C. With X7R or

X5R dielectrics, 2.2µF should be sufficient at all operating temperatures. A graph of the Region of Stable C

OUT

ESR vs. Load Current is shown in the Typical Operating

Characteristics.

_______________________________________________________________________________________ 7

Low-Noise, Low-Dropout, 200mA

Linear Regulator

Use a 0.01µF bypass capacitor at BP for low output voltage noise. Increasing the capacitance slightly decreases output noise but increases startup time. Values above

0.1µF provide no performance advantage and are not recommended (see the Shutdown Exit Delay graphs in the

Typical Operating Characteristics).

PSRR and Operation from Sources

Other than Batteries

The MAX1598 are designed to deliver low dropout voltages and low quiescent currents in battery-powered systems. Power-supply rejection is 63dB at low frequencies and rolls off above 10kHz. See the Power-

Supply Rejection Ratio Frequency graph in the Typical

Operating Characteristics.

When operating from sources other than batteries, improved supply-noise rejection and transient response can be achieved by increasing the values of the input and output bypass capacitors, and through passive filtering techniques. The Typical Operating Charac-

teristics show the MAX1598’s line- and load-transient responses.

Load-Transient Considerations

The MAX1598 load-transient response graphs (see the

Typical Operating Characteristics) show two components of the output response: a DC shift from the output impedance due to the load current change, and the transient response. Typical transient for a step change in the load current from 0 to 50mA is 12mV. Increasing the output capacitor’s value and decreasing the ESR attenuates the overshoot.

Input-Output (Dropout) Voltage

The regulator’s minimum input-output voltage differential (or dropout voltage) determines the lowest usable supply voltage. In battery-powered systems, this determines the useful end-of-life battery voltage. Because the MAX1598 uses a P-channel MOSFET pass transistor, their dropout voltage is a function of drain-to-source on-resistance (R

DS(ON)

) multiplied by the load current

(see the Typical Operating Characteristics).

___________________Chip Information

TRANSISTOR COUNT: 247

SUBSTRATE CONNECTED TO GND

_ Selector Guide

OUTPUT VOLTAGE

(xy) CODE

SOT TOP

MARK

PRESET OUTPUT

VOLTAGE (V)

THIN SOT23

MAX1598EZK25-T

MAX1598EZK28-T

MAX1598EZK29-T

MAX1598EZK30-T

MAX1598EZK32-T

MAX1598EZK33-T

MAX1598EZK36-T

MAX1598EZK50-T

Other xy**

2.50

2.80

2.84

3.00

3.15

3.30

3.60

5.00

x.y0

**Other xy between 2.5V and 5V are available in 100mV increments.

Contact factory for other versions. Minimum order quantity is 25,000 units.

MAX1598

THIN

ADRM

ADRJ

ADRN

ADRO

ADRP

ADRQ

ADRR

ADRS

8 _______________________________________________________________________________________

Low-Noise, Low-Dropout, 200mA

Linear Regulator

Package Information

(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages.)

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________ 9

© 2002 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

Mouser Electronics

Authorized Distributor

Click to View Pricing, Inventory, Delivery & Lifecycle Information:

Maxim Integrated

:

MAX1598EZK25-T MAX1598EZK28-T MAX1598EZK29-T MAX1598EZK30-T MAX1598EZK32-T MAX1598EZK33-

T MAX1598EZK36-T MAX1598EZK50-T MAX1598EZK25+T MAX1598EZK28+T MAX1598EZK29+T

MAX1598EZK30+T MAX1598EZK32+T MAX1598EZK33+T MAX1598EZK36+T MAX1598EZK50+T

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