ICS1722
QuickSaver® Charge Controller for Nickel-Cadmium
and Nickel-Metal Hydride Batteries
General Description
The
ICS1722
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
ICS1722
employs a four stage charge sequence that provides a complete
recharge without overcharging. The controller has nine user-
selectable charge rates and six user-selectable auxiliary modes
available for customized charging systems.
The
ICS1722
monitors for the presence of a battery and begins
charging when a battery is installed. The
ICS1722
is for
applications where temperature sensing is not required by the
charge controller.
Features
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Charge termination methods include:
-
Voltage slope
-
Charge timers
Four stage charge sequence:
-
Soft start charge
-
Fast charge
-
Topping charge
-
Maintenance charge
Reverse-pulse charging available in all charge stages
Nine programmable charge rates between 15 minutes (4C)
and four hours (C/4)
Continuous polling mode for battery detection
Six auxiliary modes include:
-
Discharge-before-charge
-
Ten hour C/10 conditioning charge
-
Direct to C/40 maintenance charge
-
Charging system test provided through controller
Adjustable open circuit (no battery) voltage reference
Applications
Battery charging systems for:
- Portable consumer electronics
- Power tools
- Audio/video equipment
- Communications equipment
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Block Diagram
RESET
OPEN CIRCUIT
REFERENCE
0.5V
VOLTAGE
SENSE
MODE SELECT
CHARGE
SELECT
RC
RAM
ROM
OUTPUT
CONTROL
MICROCODE CONTROL
POLLING
MODE LED
CHARGE
MODE LED
ADC
PROCESSOR
MAINTENANCE
MODE LED
CHARGE
CONTROL
DISCHARGE
CONTROL
OSCILLATOR