Pin Description

Pin

Name

Functional Description

1

VO1

150 mA, LDO1 output pin.

2

EN5

LDO5 enable input.

3

EN4

LDO4 enable input.

4

EN3

LDO3 enable input.

5

RST

Externally pulled high, open drain output to processor/memory reset.

6

IRQ

Externally pulled high, open drain output to processor interrupt indicating KYBD has gone

high.

7

PS_HOLD

Input from the processor to the LP3927. A HIGH indicates a steady supply of power is

granted. Refer to ’Application Hints’ section for more detail.

8

KYBD

An active high input signal indicating the keyboard “On/Off” button has been asserted. Refer

to ’Application Hints’ section for more detail.

9

D_GND

Digital ground, used primarily for the digital and DAC circuits.

10

VEXT

Active low input indicating a battery charger insertion Refer to ’Application Hints’ section for

more detail.

11

BYP

Reference bypass pin.

12

TEST_MODE

Pin used for production testing, factory use only. This pin should be grounded in applications.

13

LED_EN

LED driver enable input.

14

LED

LED driver, drain connection of the LED drive MOSFET.

15

LED_PGM

LED drive current programming pin.

16

OP_AMP_OUT

Operational amplifier output pin.

17

IN−

− input of the Op-Amp.

18

IN+

+ input of the Op-Amp.

19

OP_AMP_V

DD

Power supply pin for Op-Amp.

20

A_GND2

Ground for analog.

21

VO5

200 mA, LDO5 output pin.

22

V

DD3

Input power pin for LDO5. V

23

VO4

150 mA, LDO4 output pin.

24

V

DD2

Input power pin for LDO3 and LDO4. V

25

VO3

100 mA, LDO3 output pin.

26

A_GND1

Ground for analog.

27

VO2

200 mA, LDO2 output pin.

28

V

DD1

Input power pin for LDO1 and LDO2. V

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