Features
Safe charge of Li-Ion battery
packs
Pulse-width modulation control
for current and voltage regulation
Programmable high-side/low-side
current-sense
Fast charge terminated by selectable
minimum current; safety
backup termination at maximum
time
Pre-charge qualification detects
shorted or damaged cells and
conditions battery
Charging continuously qualified
by temperature and voltage limits
Direct LED control outputs to
display charge status and fault
conditions

General Description
The bq2954 Li-Ion Charge-Management
IC uses a flexible pulse-width
modulation regulator to control voltage
and current during charging.
The regulator frequency is set by an
external capacitor for design flexibility.
The switch-mode design minimizes
power dissipation.
For safety, the bq2954 inhibits fast
charging until the battery voltage
and temperature are within configured
limits. If the battery voltage is
less than the low-voltage threshold,
the bq2954 provides low-current
conditioning of the battery.
For charge qualifiction, the bq2954
uses an external thermistor to measure
battery temperature. Charging
begins when power is applied or the
battery is inserted
The bq2954 charges a battery in two
phases. First a constant-current
phase replenishes approximately
70% of battery capacity. Then a voltage-
regulation phase completes the
battery charge.
The bq2954 provides status indications
of all charger states and faults
for accurate determination of the
battery and charge-system conditions.