Triple-Output Power-Supply

Controller for Notebook Computers

_______________________________________________________________________________________

7

NAME

FUNCTION

ON3

Logic input to turn on +3.3V. Logic high turns on the regulator. Connect to VL for automatic start-up.

D1

#1 level-translator/comparator noninverting input. Inverting comparator input is internally connected to

1.650V. Controls Q1. Connect to GND if unused.

D2

1

2

D3

VH

Q3

Q2

3

4

5

Q1

#1 level-translator/comparator output. Sources 20µA from VH when D1 is high. Sinks 500µA to GND

when D1 is low, even with VH = 0V.

VPPA

0V, 5V, 12V, Hi-Z PCMCIA VPP output. Sources up to 60mA. Controlled by DA0 and DA1.

6

7

8

9

______________________________________________________________Pin Description

PIN

VDD

15V flyback input (feedback). A weak shunt regulator conducts 3mA to GND when VDD exceeds 19V.

Also the supply input to the VPP regulators.

10

VPPB

0V, 5V, 12V, Hi-Z PCMCIA VPP output. Sources up to 60mA. Controlled by DB0 and DB1.

11

GND

Low-current analog ground

12

Intel 82365 compatible PCMCIA VPP control inputs (see Table 1)

15-18

SYNC

14

REF

13

Oscillator frequency control and synchronization input: Connect to VL or to GND for f = 200kHz; connect

to REF for f = 300kHz. For external synchronization in the 240kHz to 350kHz range, a high-to-low transi-

tion causes the start of a new cycle.

DA1, DA0,

DB1, DB0

#2 level-translator/comparator output. Sources 20µA from VH when D2 is high. Sinks 500µA to GND

when D2 is low, even with VH = 0V.

#3 level-translator/comparator output. Sources 20µA from VH when D3 is high. Sinks 500µA to GND

when D3 is low, even with VH = 0V.

External supply input for level-translator/comparator. For N-channel FET drive, connect to VDD or external

+13V to +18V supply. For low-battery comparators, connect to +3.3V or +5V (or to VL/REF).

#3 level-translator/comparator noninverting input. Inverting comparator input is internally connected to

1.650V. Controls Q3. Connect to GND if unused.

#2 level-translator/comparator noninverting input. Inverting comparator input is internally connected to

1.650V. Controls Q2. Connect to GND if unused.

Logic input to turn on +5V. Logic high turns on the regulator. Connect to VL for automatic startup.

19

ON5

SS5

20

CS5

+5V-supply current-sense input. +100mV = current limit in buck mode, -100mV = current limit in flyback

mode (where the ±100mV are referenced to FB5).

21

DH5

+5V-supply external MOSFET high-side switch-drive output

22

+5V-supply soft-start control input. Ramp time to full current limit is 1ms/nF of capacitance to GND.

3.3V reference output. Sources up to 5mA for external loads. Bypass to GND with 1µF/mA load or

0.22µF minimum.

23

LX5

+5V-supply inductor connection