bq24700, bq24701

NOTEBOOK PC BATTERY CHARGE CONTROLLER

AND SELECTOR WITH DPM

SLUS452B – APRIL 2001 – REVISED NOVEMBER 2002

10

POST OFFICE BOX 655303

Terminal Functions

TERMINAL

I/O

DESCRIPTION

NAME

NO.

I/O

DESCRIPTION

ACDET

1

I

AC or adapter power detection

ACDRV

24

O

AC or adapter power source selection output

ACN

11

I

Negative differential input

ACP

12

I

Positive differential input

ACPRES

2

O

AC power indicator

ACSEL

3

I

AC adapter power select

ACSET

6

I

Adapter current programming voltage

ALARM

19

O

Depleted battery alarm output

BATDEP

4

I

Depleted battery level

BATDRV

23

O

Battery power source select output

BATP

13

I

Battery charge regulation voltage measurement input to the battery-voltage gm amplifier

BATSET

9

I

External override to an internal 0.5% precision reference

COMP

10

O

Inverting input to the PWM comparator

ENABLE

8

I

Charge enable

GND

17

O

Supply return and ground reference

IBAT

14

O

Battery current differential amplifier output

PWM

21

O

Gate drive output

SRN

15

I

Negative differential battery current sense amplifier input

SRP

16

I

Positive differential battery current sense amplifier input

SRSET

5

I

Battery charge current programming voltage

VCC

22

I

Operational supply voltage

VHSP

20

O

Voltage source to drive gates of the external MOSFETs

VREF

7

O

Precision voltage 5-V,

±0.6% reference

VS

18

I

System (load) voltage input pin

pin assignments

ACDET: AC or adapter power detection. This input pin is used to determine the presence of the ac adapter.

When the voltage level on the ACDET pin is less than 1.20 V, the bq24700/bq24701 is in sleep mode, the PWM

control is disabled, the BATDRV is driven low and the ACDRV is driven high. This feature can be used to

automatically select battery as the system’s power source.

ACDRV: AC or adapter power source select output. This pin drives an external P-channel MOSFET used to

switch to the ac wall-adapter as the system’s power source. When the ACSEL pin is high while the voltage on

when the ACDET is less than 1.20 V.

ACN, ACP: Negative and positive differential inputs, respectively for ac-to-dc adapter current sense resistor.

ACPRES: This open-drain output pin is used to indicate the presence of ac power. A logic high indicates there

is a valid ac input. A low indicates the loss of ac power. ACPRES is high when the voltage level on the ACDET

pin is greater than 1.20 V.

ACSEL: AC adapter power select. This input selects either the ac adapter or the battery as the power source.

A logic high selects ac power, while a logic low selects the battery.