Features

Fast charge of nickel cadmium
or nickel-metal hydride batteries

Direct LED output displays
charge status

Fast-charge termination by -
V,
maximum voltage, maximum
temperature, and maximum
time

Internal band-gap voltage reference

Optional top-off charge

Selectable pulse trickle charge
rates

Low-power mode

8-pin 300-mil DIP or 150-mil
SOIC

General Description
The bq2002E and bq2002G Fast-
Charge ICs are low-cost CMOS battery-
charge controllers providing reliable
charge termination for both NiCd
and NiMH battery applications. Controlling
a current-limited or constant-
current supply allows the
bq2002E/G to be the basis for a costeffective
stand-alone or system-integrated
charger. The bq2002E/G integrates
fast charge with optional top-off
and pulsed- trickle control in a single
IC for charging one or more NiCd or
NiMH battery cells.
Fast charge is initiated on application
of the charging supply or battery replacement.
For safety, fast charge is
inhibited if the battery temperature
and voltage are outside configured
limits.
Fast charge is terminated by any of
the following:

Peak voltage detection (PVD)

Negative delta voltage (-
V)

Maximum voltage

Maximum temperature

Maximum time
After fast charge, the bq2002E/G optionally
tops-off and pulse-trickles the
battery per the pre-configured limits.
Fast charge may be inhibited using
the INH pin. The bq2002E/G may
also be placed in low-standby-power
mode to reduce system power consumption.
The bq2002E differs from the
bq2002G only in that a slightly different
set of fast-charge and top-off
time limits is available. All differences
between the two ICs are illustrated
in Table 1.