SS6782G Datasheet, PDF (1/19 Pages) Silicon Standard Corp. – Charge Controller for Dual Batteries

SS6782G
Charge Controller for Dual Batteries
FEATURES
Quick and easy testing for production.
Sequential charging control of two
NiMH/NiCd Battery Packs.
Reliable sequential fast charge control of dual
NiMH and/or NiCd Battery Packs, even
with a fluctuating charging current.
Fast charge termination by: ∆T∆t, -∆V, 0∆V,
safety timer, maximum temperature,
or maximum voltage.
Linearly adjustable safety timer and ∆T∆t
detection slope line.
Selectable battery voltage protection range.
Selectable battery temperature protection mode.
Protection against battery voltage and battery
temperature faults.
Selectable LED display mode for battery status.
Five pulsed trickle charge modes.
Discharge-before-charge function available to
eliminate memory effect.
Choice of 20-pin DIP or 20-pin SOP packages.
APPLICATIONS
Dual-Battery Fast Chargers for:
Mobile Phones.
Notebook and Laptop Personal Computers.
Portable Power Tools and Toys.
Portable Communication Equipments.
Portable Video & Stereo Equipments.
1.55
100
Charge Current = 600mA
Cell Capacity = 550mA
NiMH Battery
1.45
80
Cell Voltage
1.35
60
1.25
40
Temperature
1.15
0
10
20
30
40
50
Charge Time (min.)
20
60
Fig. 1
Battery charging characteristics from an
SS6782G-controlled charger with a
fluctuating charging current.
DESCRIPTION
The SS6782G fast-charge controller is designed
for intelligent sequential charging of dual NiMH
and NiCd batteries without the risk of malfunction.
After powering on, the SS6782G charging sequence
gives priority to battery pack A, represented by
input signals at the ATS and ABV pins, over
battery pack B, represented by BTS and BBV
pin signals. The SS6782G automatically switches
to charging the standby battery pack after the
battery pack being charged finishes charging or
encounters a fault condition.
-∆ V (-0.25%) detection, 0∆V (peak voltage timer)
detection, and ∆T∆t detection are the primary
methods employed by the SS6782G 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.
Both ∆T∆t and -∆V detection methods have been
proved powerful in terminating fast charging for
NiMH and NiCd batteries. The SS6782G utilizes
the combination of these two methods to make
a reliable decision for ending fast charge and to
avoid issues caused by using -∆V detection
alone under certain conditions. Fig. 1 shows an
example of a charging curve of a battery charged by
a fluctuating current from a NiMH battery charger
which uses the SS6782G controller IC to achieve
optimal charging. The ∆T∆t or -∆V detection cir-
cuitry may be disabled independently for different
applications, such as system-integrated chargers,
chargers with varying charge current, or battery
packs lacking a temperature-sensing thermistor.
9/21/2005 Rev.3.01
www.SiliconStandard.com
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