BQ2031PN-A5 Datasheet, PDF (1/19 Pages) Texas Instruments – Lead-Acid Fast-Charge IC

bq2031
Lead-Acid Fast-Charge IC
Features
➤ Conforms to battery manufactur-
ers' charge recommendations for
cyclic and float charge
➤ Pin-selectable charge algorithms
- Two-Step Voltage with
temperature-compensated
constant-voltage maintenance
- Two-Step Current with
constant-rate pulsed current
maintenance
- Pulsed Current: hysteretic,
on-demand pulsed current
➤ Pin-selectable charge termination
by maximum voltage,∆²V, mini-
mum current, and maximum
time
➤ Pre-charge qualification detects
shorted, opened, or damaged cells
and conditions battery
➤ Charging continuously qualified by
temperature and voltage limits
➤ Internal temperature-compen-
sated voltage reference
➤ Pulse-width modulation control
- Ideal for high-efficiency
switch-mode power conversion
- Configurable for linear or
gated current use
➤ Direct LED control outputs dis-
play charge status and fault con-
ditions
General Description
The bq2031 Lead-Acid Fast Charge
IC is designed to optimize charging
of lead-acid chemistry batteries. A
flexible pulse-width modulation
regulator allows the bq2031 to con-
trol constant-voltage, constant-
current, or pulsed-current charging.
The regulator frequency is set by an
external capacitor for design flexi-
bility. The switch-mode design keeps
power dissipation to a minimum for
high charge current applications.
A charge cycle begins when power is
applied or the battery is replaced.
For safety, charging is inhibited un-
til the battery voltage is within con-
figured limits. If the battery voltage is
less than the low-voltage threshold,
the bq2031 provides trickle-current
charging until the voltage rises into
the allowed range or an internal
timer runs out and places the
bq2031 in a Fault condition. This
procedure prevents high-current
charging of cells that are possibly
damaged or reversed. Charging is
inhibited anytime the temperature
of the battery is outside the config-
urable, allowed range. All voltage
thresholds are temperature-
compensated.
The bq2031 terminates fast (bulk)
charging based on the following:
I Maximum voltage
I Second difference of cell voltage
(∆²V)
I Minimum current (in constant-
voltage charging)
I Maximum time-out (MTO)
After bulk charging, the bq2031 pro-
vides temperature-compensated
maintenance (float) charging to
maintain battery capacity.
Pin Connections
Pin Names
TMTO
1
FLOAT
2
BAT
3
VCOMP
4
ICOMP
5
IGSEL
6
SNS
7
TS
8
16
LED2/DSEL
15
LED1/TSEL
14
MOD
13
VCC
12
VSS
11
COM
10
LED3/QSEL
9
TPWM
16-Pin Narrow
DIP or SOIC
PN203101.eps
TMTO
FLOAT
BAT
VCOMP
ICOMP
IGSEL
SNS
TS
TPWM
Time-out timebase input
State control output
Battery voltage input
Voltage loop comp input
Current loop comp input
Current gain select input
Sense resistor input
Temperature sense input
Regulator timebase input
LED3/
QSEL
COM
VSS
VCC
MOD
LED1/
TSEL
LED2/
DSEL
Charge status output 3/
Charge algorithm select
input 1
Common LED output
System ground
5.0V± 10% power
Modulation control
output
Charge status output 1/
Charge algorithm select
input 2
Charge status output 2/
Display select input
SLUS156–JUNE 1999 E
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