FEATURING

Extended

Commercial

Temperature

Range

–20°C

to 70°C

for Portable

Handheld

Equipment

1

GENERAL DESCRIPTION

The ML4880 Portable PC and PCMCIA Power Controller

is a complete solution for DC/DC power conversion for

portable computing systems with single or multiple

PCMCIA slots.

The device provides two synchronous buck controllers to

implement mixed voltage systems and a flyback controller

architecture enables generation of high currents (150mA

or more per slot) on the 12V bus for multiple slot PCMCIA

applications.

Each regulator can be independently switched off to fully

isolate the load from the power supply. The PFM

architecture will automatically adjust switching frequency

at light loads in order to maintain power conversion

efficiencies in excess of 90% over a wide output power

range.

(* Indicates Part is End Of Life as of July 1, 2000)

FEATURES

s

Regulation to

±3% maximum: provides 2% PCMCIA

switch matrix margin

s

Two synchronous buck controllers for 3.3/3V, 5V

generation, and a flyback for high current, 12V

generation from 5.5V to 18V input

s

Regulator power conversion efficiencies > 90%

s

Pulse frequency modulation for high efficiency

operation

s

Independent regulator shutdown for full load isolation

s

Adjustable current limit

s

Wide input voltage range (5.5V to 18V)

July 2000

Portable PC/PCMCIA Power Controller

BLOCK DIAGRAM

P DRV A

N DRV A

VOUT A

2.5 – 3.5V

+

–

ISENSE A

VFB A

N DRV C

ISENSE C

PWR GND C

VFB C

VOUT C

6V – 15V

+

–

17

3

21

12

10

16

6

TO SYSTEM

POWER

MANAGEMENT

GND

VIN

SHDN C

SHDN B

SHDN A

BIAS

CIRCUITS

18

11

7

13

14

4

9

VIN

5.5 – 18V

P DRV B

N DRV B

VOUT B

4.5 – 5.0V

+

–

ISENSE B

VFB B

19

20

5

8

VIN

VIN

SHUTDOWN

LOGIC

GND

15

GATE

CLAMP

24

CLAMP

23

PWR GND A

22

PWR GND B

GATE

CLAMP

CLAMP

CLAMP A

2

CLAMP B

1