Philips Semiconductors

Product data

NE57610

Li-ion battery charger control

with adjustable thresholds

2002 Nov 05

4

PIN DESCRIPTION

PIN

SYMBOL

I/O

DESCRIPTION

1

ON/OFF

I

ON/OFF:

When LOW, the charger operates. When HIGH, it inhibits all functions of the charger.

2

RESET

I

RESET:

In a LOW state all charger functions are enabled. When the pin is brought HIGH, all of the charger

functions are inhibited and when brought to a LOW state again, all of the timers are initialized and the start-up

functions are enabled.

3

TP1

O

Test Point 1:

This pin is the output of the center counter of the pre-charger timer counter. This pin will slowly

toggle between a HIGH state and a LOW state during the pre-charge period.

4

TP2

O

Test Point 2:

This pin is the output of the center counter in the high-rate charger counter. This pin will slowly

toggle between a HIGH state and a LOW state during the high-rate charging period.

5

O

Reference voltage:

This is an output of a temperature stabilized 1.2 V reference. It is used in the bias of the

thermocouple and for adjustment of the ADJ1–ADJ4 pins.

6

GND1

–

Ground.

7

GND2

–

Ground.

8

ADJ1

I

Overcurrent threshold adjustment pin:

This pin is internally set to 1.16 V. The overvoltage trip point is set

too high at this voltage to become active. This is useful where the input power source is a current-limited wall

transformer. It may be adjusted by referring to ‘Use of the ADJ1–ADJ4 pins’.

9

ADJ2

I

Charge termination current threshold adjustment pin:

At the top-of-charge, when the charge current falls

below this level, the charging cycle is terminated. This pin is internally set to 62 mV. It may be adjusted by

referring to ‘Use of the ADJ1–ADJ4 Pins’.

10

ADJ3

I

Pre-charge current adjustment pin:

This adjusts the amount of current entering the battery during the

pre-charge period. It is internally set to 120 mV. It may be adjusted by referring to ‘Use of the ADJ1–ADJ4 Pins’.

11

ADJ4

I

High-rate current adjustment pin:

This pin controls the amount of charge current during the high-rate of

charge period. The pin is internally set to 89 mV. It may be adjusted by referring to ‘Use of the ADJ1–ADJ4

Pins’.

12

TEMP

I

Battery temperature sensing pin:

This pin inhibits the charging process if the voltage presented to this pin

falls outside an acceptable temperature range. The external voltage is created by resistor network that includes

a thermocouple.

13

BAT1

I

Battery voltage sensing pin:

This pin senses the battery voltage.

14

BAT2

I

Battery voltage and current sensing pin:

This pin senses battery voltage but also is one of the two leads

for sensing charging current. (CS is the other current sensing pin.)

15

CS

I

Current sensing pin:

This pin is one of the two current sensing pins. (BAT2 is the other pin.)

16

COMP

I

Current regulation amplifier compensation pin:

It is recommended that around 100 pF be connected

between this pin and the DRV pin. This capacitor improves the phase margin of the system.

17

DRV

O

External PNP transistor base drive pin:

This pin directly drives the base of an external PNP bipolar

transistor.

18

I

The positive voltage supply pin.

19

ADJ5

I

Full charge termination voltage adjust pin:

This pin, when grounded will increase the termination voltage

by 15 mV.

20

VINOK

I

Input voltage overvoltage indicator:

This pin is LOW if the input voltage is over the maximum input voltage.

The pin is HIGH when the input voltage is not above the maximum input voltage.

21

G_LED

O

Green LED driver pin.

This is an open collector output which is connected to a green LED though a series

resistor to limit the current to less than 20 mA to the input voltage.

22

R_LED

O

Red LED driver pin.

This is an open collector output which is connected to a red LED though a series resistor

to limit the current to less than 20 mA to the input voltage.

23

OSC1

O

Oscillator out pin:

This pin is connected through a timing resistor to the OSC2 pin to set the frequency of the

oscillator and the period of the timers.

24

OSC2

I

Oscillator in pin:

This pin is connected through a timing resistor to the OSC1 pin and a timing capacitor to