ICS1708

QuickSaver® Charge Control IC for Nickel-Cadmium

and Nickel-Metal Hydride Batteries

General Description

The ICS1708 is a low cost 8 pin CMOS control IC for the intelligent charging of either nickel-cadmium (NiCd) or nickel-metal hydride

(NiMH) batteries. The ICS1708 uses a pulsed-current charging technique together with multiple voltage slope termination methods. The

ICS1708 employs a four stage charge sequence that provides a complete recharge without overcharging. The controller has three (3) user

selectable charge rates, user accessible clock, and two (2) charge status output pins. On power-up, the ICS1708 monitors for the presence of

a battery and begins charging. The ICS1708 is for applications where battery temperature protection is not required of the charge controller.

Applications

Embedded and charger stands for: Portable consumer products, Power tools, Audio/video products, Communications products, RC toys,

and Wireless products

Features

•

Charge termination methods include: Voltage slope (+

•

Four stage charge sequence:

•

Three (3) user selectable charge rates: 15 minutes (4C), 60 minutes (1C), 150 minutes (C/2.5)

•

Continuous polling mode for battery detection

•

Adjustable open circuit (no battery) voltage reference

•

Peak battery performance and extended cycle life

•

Improved battery efficiency and reliability

•

Lower internal resistance build-up

•

Lower capacity fade

Block Diagram

CURRENT

SOURCE

BATTERY

VOLTAGE

SENSE

OPEN CIRCUIT

REFERENCE

VOLTAGE

PROCESSOR

MICROCODE CONTROL

ADC

RAM

ROM

OUTPUT

CONTROL

0.5V

FAST

CHARGE

CHARGE

COMPLETE

RC (CLOCK)

OSCILLATOR