SC1406

© 1999 SEMTECH CORP.

652 MITCHELL ROAD

NEWBURY PARK CA 91320

PORTABLE PENTIUM

POWER SUPPLY CONTROLLER

PRELIMINARY - August 27, 1999

2

Pentium is a registered trademark of Intel Corporation

PIN DESCRIPTION:

Pin

Pin Name

Pin Function

1

HYS

Core comparator hysteresis settling.

2

CLSET

Current limit setting pin.

3

VCOUT

Voltage clamp output.

4

VCIN

Voltage clamp input.

5

VCBYP

Voltage clamp bypass pin.

6

VID4

VID most significant bit input.

7

VID3

VID input

8

VID2

VID input

9

VID1

VID input

10

VID0

VID least significant bit input.

11

BASE25

2.5V Linear regulator drive.

12

FB25

2.5V Linear regulator output feedback.

13

BASE15

1.5V Linear regulator drive.

14

FB15

1.5V Linear regulator output feedback.

15

EN

Enables the IC when high. This is capable of accepting 5.0V signal level.

16

PWRGD

When the main converter output is within +10% of the VID DAC setting, this signal is

driven high to VCC level. Internal pull-down 100K.

17

LBIN

Low battery input. This pin is used to set the minimum voltage to the converter.

When the input to this pin is less than 1.225V, the converter is held in an Under-Voltage-

Lock-Out mode regardless of the status of EN.

18

SSLR

Linear regulators soft start. During power-up, the external soft-start capacitor (1200pF,

typ) is charged by an internal 1µA current source to set the ramp up time of the linear

regulator outputs, 1.5V and 2.5V. This ramp up time is typically 2ms, 6ms max. This is

discharged when BIASEN (internal signal) is low.

19

SSCORE

Main controller output soft start. During power-up, the external Soft-Start capacitor

(1800pF, typ) is charged by an internal 1µA current source to set the ramp up time of the

main converter output. This ramp up time is typically 3ms, 6ms max. This is discharged

when BIASEN is low. Core soft start current tolerance tracks the LDO soft start current to

within 10%.

20

CORE

Converter output feedback.

21

DAC

VID digital to analog output.

22

GND

Ground

23

CO

Comparator output. Main regulator controller output. Internal pull-down 100K.

24

VCC

Supply voltage.

25

CMP

Core comparator input pin.

26

CMPREF

Core comparator reference input pin.

27

CL

Current limit input pin.

28

CLREF

Current limit reference input pin.