1
Features
➤ Fast charge of nickel cadmium
or nickel-metal hydride batter-
ies
➤ Direct LED output displays
charge status
➤ Fast-charge termination by -∆V,
maximum voltage, maximum
temperature, and maximum
time
➤ Internal band-gap voltage ref-
erence
➤ Optional top-off charge
➤ Selectable pulse trickle charge
rates
➤ Low-power mode
➤ 8-pin 300-mil DIP or 150-mil
SOIC
General Description
The bq2002 and bq2002/F 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 bq2002/F to be the
basis for a cost-effective stand-alone or
system-integrated charger. The
bq2002/F integrates fast charge with
optional top-off and pulsed-trickle con-
trol 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 re-
placement. 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:
c110 Peak voltage detection (PVD)
c110 Negative delta voltage (-∆V)
c110 Maximum voltage
c110 Maximum temperature
c110 Maximum time
After fast charge, the bq2002/F op-
tionally tops-off and pulse-trickles the
battery per the pre-configured limits.
Fast charge may be inhibited using
the INH pin. The bq2002/F may also
be placed in low-standby-power mode
to reduce system power consumption.
The bq2002F differs from the
bq2002 only in that a slightly differ-
ent set of fast-charge and top-off
time limits is available. All differ-
ences between the two ICs are illus-
trated in Table 1.
NiCd/NiMH Fast-Charge Management ICs
bq2002/F
TM Timer mode select input
LED Charging status output
BAT Battery voltage input
V
SS
System ground
1
PN-200201.eps
8-Pin DIP or
Narrow SOIC
2
3
4
8
7
6
5
TM
LED
BAT
V
SS
CC
INH
V
CC
TS
TS Temperature sense input
V
CC
Supply voltage input
INH Charge inhibit input
CC Charge control output
Pin Connections Pin Names
bq2002/F Selection Guide
Part No. TCO HTF LTF -∆V PVD Fast Charge tMTO Top-Off Maintenance
bq2002 0.5 ∗ VCC None None
✔ C/2 160 C/32 C/64
✔ 1C 80 C/16 C/64
✔ 2C 40 None C/32
bq2002F 0.5 ∗ VCC None None
✔ C/2 160 C/32 C/64
✔ 1C 100 C/16 C/64
✔ 2C 55 None C/32
SLUS131–JANUARY 1999 D