General Description

The MAX8737 dual high-power linear regulator con-

trollers use external n-channel MOSFETs to generate

two independent low-voltage supplies for notebook

computers. The MAX8737 delivers low output voltages

from 0.5V to 2.5V (±5mV no-load accuracy). The exter-

nal components allow scalable current design with

loads up to 5A with excellent load regulation (1%). The

regulator operates from a low input voltage, which also

reduces the power dissipation in the external n-channel

MOSFET. The controller powers the external MOSFET

gate driver from the standard 5V system supply.

The MAX8737 includes current and thermal limits to

prevent damage to the linear regulator. The MAX8737

uses an external resistive divider to fold back the cur-

rent limit, reducing the overall power dissipation. The

MAX8737 uses an external resistive-divider in series

with the current-sense input (CS_), providing foldback

current-limit protection, and effectively reducing the

short-circuit power dissipation.

An output undervoltage timeout is available for low-cost

applications that omit the current-sense resistor. The

output undervoltage (UVP) timing depends on the mag-

shuts down the LDO if the output voltage drops out of

regulation. The controller uses an adjustable reference

input (REFIN_) to set the nominal output voltage

bility independent of the output voltage.

Each linear regulator features an adjustable soft-start

function, and generates a delayed power-good

(PGOOD) signal that signals when the linear regulator

is in regulation. The MAX8737 is a low-cost solution

requiring few external components and is available in a

small, 4mm x 4mm, 16-pin thin QFN package.

Applications

Notebook and Desktop Computers

Point-of-Load Regulators

Low-Voltage Bias Supplies

Servers

Features

♦ Low-Cost Dual Linear Regulators

♦ Output Voltage Accuracy ±5mV

♦ Independent 0.5V to 2.5V Reference Inputs

♦ Foldback Current-Limit Protection

♦ Output Undervoltage-Lockout Protection

♦ Thermal Limit (Internal Sensor)

♦ 1.0V to 5.5V Input Supply Voltage (External FET

Drain)

♦ 5V Bias Supply Voltage

♦ Independent Power-Good Open-Drain Outputs

♦ Independent Enable Inputs

♦ Soft-Shutdown Output Discharge

♦ Low Supply Current (0.5mA)

♦ 5µA (max) Shutdown Supply Current

Dual, Low-Voltage Linear Regulator Controllers

with External MOSFETs

________________________________________________________________ Maxim Integrated Products

1

16

12

34

12

11

10

9

15

14

13

5

6

7

8

DRV1

GND

N.C.

DRV2

PGOOD2

PGOOD1

EN2

EN1

TOP VIEW

MAX8737

4mm x 4mm TQFN

Pin Configuration

19-3705; Rev 0; 5/05

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at

1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

EVALUATION

KIT

AVAILABLE

Ordering Information

PART

TEMP RANGE PIN-PACKAGE

MAX8737ETE

-40°C to +85°C 16 Thin QFN-EP* 4mm x 4mm

MAX8737ETE+ -40°C to +85°C 16 Thin QFN-EP* 4mm x 4mm

*EP = Exposed pad.