AIC1781A
Battery Charge Controller
FEATURES
DESCRIPTION
n
n
l Fast Charge Control of NiMH/NiCd Batteries,
The AIC1781A fast charge controller IC is
designed for intelligent charging of NiMH or NiCd
even with a Fluctuating Charging Current.
DT / Dt
- DV
,
l Fast Charge Termination by:
0DV
,
- DV
detection (peak
detection are the
batteries without the risk of overcharge.
, Safety Timer, Maximum Temperature,
0DV
Detection
(-0.25%),
Maximum Voltage.
l Linearly Adjustable
Safety Timer.
DT / Dt
voltage timer) and
DT / Dt
Detection Slope and
0DV
primary methods employed by the AIC1781A to
terminate fast charge. The fast charge can also be
cut off by maximum battery voltage and maximum
battery temperature detection along with the
safety timer to prevent charging under fault
conditions of the charging system or the battery
itself.
l Adjustable Peak Voltage Timer for
.
l Battery Voltage Protection Range Selectable.
l Selectable Battery Temperature Protection
Mode.
l Protection against Battery Voltage and Battery
Temperature Faults.
l Selectable LED Display Mode for Battery Status.
l Five Pulsed Trickle Charge Modes.
l Discharge-before-Charge Function Available for
Eliminating Memory Effect.
DT / Dt
- DV
detection methods have
Both
and
been proved powerful in terminating fast charging
for NiMH and NiCd batteries. The AIC1781A
utilizes the combination of these two methods to
achieve reliable decision of ending fast charge and
l Quick and Easy Testing for Production.
l 16-pin DIP or SO Packages.
- DV
prevent misacting caused by using
detection
APPLICATIONS
Battery Fast Chargers for:
n
alone under certain conditions. Fig. 1 shows an
example of charging curve of a battery charged by
a fluctuating current from a NiMH battery charger,
which uses the AIC1781A controller IC to achieve
optimal charging. This technique, in cooperating
l Mobile Phones.
l Notebook and Laptop Personal Computers.
l Portable Power Tools and Toys.
l Portable Communication Equipments.
l Portable Video & Stereo Equipments.
0DV
with the
detection (peak voltage timer), is
particularly suitable for NiMH batteries, whose
voltage drop is hardly significant yet temperature
100
1.55
Charge Current = 600 mA
Cell Capacity = 550 mA
NiMH Battery
DT / Dt
- DV
rises rapidly. The
or
detection
80
1.45
circuitry may be disabled independently for
different applications, such as system-integrated
chargers, chargers with varying charge current, or
battery packs lack of temperature sensing
thermistor.
Cell Voltage
60
1.35
40
1.25
Temperature
20
1.15
0
10
20
30
40
50
60
The safety timer period, mode of battery
temperature protection, battery voltage protection
range, pulsed trickle charge duty, and LED display
mode are all adjustable or selectable.
Charge Time (min.)
Fig. 1 Battery Charging Characteristics Resulting from
an AIC1781A-Controlled Charger with
Fluctuating Charging Current
a
Analog Integrations Corporation
4F, 9 Industry E. 9th Rd, Science-Based Industrial Park, Hsinchu, Taiwan
TEL: 886-3-5772500 FAX: 886-3-5772510 www.analog.com.tw
DS-1781AP-01 011604
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