ICS1700A

QuickSaver® Charge Controller for Nickel-Cadmium

and Nickel-Metal Hydride Batteries

General Description

The ICS1700A is a CMOS device designed for the intelligent

charge control of either nickel-cadmium (NiCd) or nickel-metal

hydride (NiMH) batteries. The controller uses a pulsed-current

charging technique together with voltage slope termination. The

ICS1700A employs a four stage charge sequence that provides a

complete recharge without overcharging. The controller has four

user-selectable charge rates available for customized charging

systems. The ICS1700A is a pin-for-pin replacement for the

original ICS1700 controller.

The ICS1700A monitors for the presence of a battery and begins

charging if a battery is installed within the first 10 seconds after a

reset. Voltage and temperature are measured to ensure a battery is

within fast charge conditions before charge is initiated.

Applications

Battery charging systems for:

-

Portable consumer electronics

-

Power tools

-

Audio/video equipment

-

Communications equipment

-

Wireless handsets

Features

•

Multiple charge termination methods include:

-

Voltage slope

-

Maximum temperature

-

Charge timer

•

Four stage charge sequence:

-

Soft start charge

-

Fast charge

-

Topping charge

-

Maintenance charge

•

Reverse-pulse charging available in all charge stages

•

Four programmable charge rates between 15 minutes (4C) and

two hours (C/2)

•

Out-of-temperature range detection

-

Hot battery: charger shutdown

-

Cold battery: low current charge

•

Ten second polling mode for battery detection

•

Battery fault with shutdown protection

Block Diagram

CHARGE

DISCHARGE

TEMPERATURE

SENSE

SELECT

CHARGE

VOLTAGE

SENSE

PROCESSOR

MICROCODE CONTROL

ADC

RAM

ROM

OUTPUT

CONTROL

RESET

2.0V

0.5V

HOT

COLD

CHARGE

MODE LED

CONTROL

CONTROL

POLLING/

FAULT LED

TEMPERATURE

STATUS LED

OSCILLATOR

RC