General Description

The MAX8563/MAX8564/MAX8564A ultra-low-output dual

and triple LDO controllers allow flexible and inexpensive

point-of-load voltage conversion in motherboards,

desknotes, notebooks, and other applications.

These parts feature a 0.5V reference voltage with ±1%

accuracy providing tight regulation of the output volt-

age. The MAX8563 has three n-channel MOSFET con-

troller outputs, and the MAX8564/MAX8564A has two

controller outputs.

Each controller output is adjustable from 0.5V to 3.3V

= 5V. Each output is independently enabled and asserts

a POK signal when the output reaches 94% of the set

value. Each output is protected against a soft short-circuit

condition by an undervoltage comparator that disables

the output when it drops to under 80% of the set voltage

for more than 50µs. For a catastrophic short condition, the

regulators are shut down immediately if the output drops

below 60% of the set voltage.

The MAX8563 is available in a 16-pin QSOP

package, and the MAX8564/MAX8564A are available

Applications

Features

♦ MAX8563: 3 Outputs

♦ MAX8564/MAX8564A: 2 Outputs

♦ ±1% Feedback Regulation

♦ Adjustable Output Voltage Down to 0.5V

♦ Can Use Ceramic Output Capacitors

♦ Wide Supply Voltage Range Permits Operation

from 5V or 12V Rails

♦ Individual Enable Control and POK Signal Allows

Sequencing

♦ Overload Protection Against Soft Short-Circuit

Condition

♦ Undervoltage Short-Circuit Protection

♦ Drive n-Channel MOSFETs

±1%, Ultra-Low Output Voltage, Dual and Triple

Linear n-FET Controllers

________________________________________________________________ Maxim Integrated Products

1

Ordering Information

19-3290; Rev 2; 6/06

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

PART

TEMP RANGE

PIN-

PACKAGE

PKG

CODE

MAX8563EEE

-40°C to +85°C

16 QSOP

E16-1

MAX8564EUB

-40°C to +85°C

10 µMAX

U10-2

MAX8564AEUB+

-40°C to +85°C

10 µMAX

U10-2

OFF

ON

OFF

ON

OFF

ON

DRV1

FB1

EN1

POK1

GND

N.C.

DRV3

FB3

DRV2

FB2

EN2

POK2

N.C.

POK3

EN3

MAX8563

1.8V

±5% IN

C1

C5

R2

R1

C4

OUT1

1.5V/1.5A

R3

Q1

POK1

3.3V

±5% IN

OUT3

2.5V/2A*

C9

C10

C8

Q3

R8

R7

R9

R6

R5

R4

C6

C2

C3

C7

Q2

OUT2

1.05V/3A

POK2

POK3

1.2V

±5% IN

Typical Operating Circuit

Pin Configurations appear at end of data sheet.

µMAX is a registered trademark of Maxim Integrated Products, Inc.

+Denotes lead-free package.

Motherboards

Dual/Triple Power Supplies

Desknotes and Notebooks

Graphic Cards

Ultra-Low-Dropout

Voltage Regulators

Low-Voltage DSP, µP, and

Microcontroller Power

Supplies