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.