BQ2004 Datasheet, PDF (1/15 Pages) Texas Instruments – Fast-Charge IC

bq2004
Fast-Charge IC
Features
➤ Fast charge and conditioning of
nickel cadmium or nickel-metal
hydride batteries
➤ Hysteretic PWM switch-mode
current regulation or gated con-
trol of an external regulator
➤ Easily integrated into systems or
used as a stand-alone charger
➤ Pre-charge qualification of tem-
perature and voltage
➤ Configurable, direct LED outputs
display battery and charge status
➤ Fast-charge termination by ∆ tem-
perature/∆ time, peak volume de-
tection, -∆V, maximum voltage,
maximum temperature, and maxi-
mum time
➤ Optional top-off charge and
pulsed current maintenance
charging
➤ Logic-level controlled low-power
mode (< 5µA standby current)
General Description
The bq2004 Fast Charge IC pro-
vides comprehensive fast charge con-
trol functions together with high-speed
switching power control circuitry on a
monolithic CMOS device.
Integration of closed-loop current
control circuitry allows the bq2004
to be the basis of a cost-effective so-
lution for stand-alone and system-
integrated chargers for batteries of
one or more cells.
Switch-activated discharge-before-
charge allows bq2004-based chargers
to support battery conditioning and
capacity determination.
High-efficiency power conversion is
accomplished using the bq2004 as a
hysteretic PWM controller for
switch-mode regulation of the charg-
ing current. The bq2004 may alterna-
tively be used to gate an externally
regulated charging current.
Fast charge may begin on applica-
tion of the charging supply, replace-
ment of the battery, or switch de-
pression. For safety, fast charge is
inhibited unless/until the battery
temperature and voltage are within
configured limits.
Temperature, voltage, and time are
monitored throughout fast charge.
Fast charge is terminated by any of
the following:
n Rate of temperature time
(∆ T/∆ t)
n Peak voltage detection (PVD)
n Negative delta voltage (-∆ V)
n Maximum voltage
n Maximum temperature
n Maximum time
After fast charge, optional top-off
and pulsed current maintenance
phases are available.
Pin Connections
DCMD
1
DSEL
2
VSEL
3
TM1
4
TM2
5
TCO
6
TS
7
BAT
8
16
INH
15
DIS
14
MOD
13
VCC
12
VSS
11
LED2
10
LED1
9
SNS
16-Pin Narrow DIP
or Narrow SOIC
PN2004E01.eps
SLUS063A–FEBRUARY 2001 G
Pin Names
DCMD
DSEL
VSEL
TM1
TM2
TCO
TS
BAT
Discharge command
Display select
Voltage termination
select
Timer mode select 1
Timer mode select 2
Temperature cutoff
Temperature sense
Battery voltage
SNS
LED1
LED2
VSS
VCC
MOD
DIS
INH
Sense resistor input
Charge status output 1
Charge status output 2
System ground
5.0V ±10% power
Charge current control
Discharge control
output
Charge inhibit input
1