BQ2005_13 Datasheet, PDF (2/18 Pages) Texas Instruments – Fast- Charge IC for Dual-Bat tery Packs

bq2005
Pin Descriptions
DISA
DCMDA Discharge-before-charge control input,
battery A
DVEN
DCMDA controls the discharge-before-charge
function of the bq2005. A negative-going
pulse on DCMDA initiates a discharge to
EDV followed by a charge if conditions allow.
By tying DCMDA to ground, automatic
discharge-before-charge is enabled on every
new charge cycle start.
-∆ V enable input
CHA,
CHB
FCCA,
FCCB
This input enables/disables -∆ V charge termi-
nation. If DVEN is high, the -∆ V test is en-
abled. If DVEN is low, -∆ V test is disabled.
The state of DVEN may be changed at any
time.
MODA,
MODB
TM1–
TM2
TCO
Timer mode inputs
TM1 and TM2 are three-state inputs that con-
figure the fast charge safety timer, -∆V hold-
off time, and that enhance/disable top-off.
See Table 2.
Temperature cutoff threshold input
VCC
Input to set maximum allowable battery _Vss
temperature. If the potential between TSA
and SNSA or TSB and SNSB is less than the
voltage at the TCO input, then fast charge or
top-off charge is terminated for the corre-
sponding battery pack.
TSA,
TSB
Temperature sense inputs
Input, referenced to SNSA or SNSB, respec-
tively, for an external thermistor monitoring
battery temperature.
BATA,
BATB
Voltage inputs
The battery voltage sense input, referenced to
SNSA,B, respectively. This is created by a
high-impedance resistor divider network con-
nected between the positive and the negative
terminals of the battery.
SNSA,
SNSB
Charging current sense inputs,
SNSA,B controls the switching of MODA,B
based on the voltage across an external
sense resistor in the current path of the bat-
tery. SNS is the reference potential for the
TS and BAT pins. If SNS is connected to
VSS, MOD switches high at the beginning of
charge and low at the end of charge.
Discharge control output
Push-pull output used to control an external
transistor to discharge battery A before
charging.
Charge status outputs
Push-pull outputs indicating charging status
for batteries A and B, respectively. See Fig-
ure 1 and Table 2.
Fast charge complete outputs
Open-drain outputs indicating fast charge
complete for batteries A and B, respectively.
See Figure 1 and Table 2.
Charge current control outputs
MODA,B is a push-pull output that is used to
control the charging current to the battery.
MODA,B switches high to enable charging
current to flow and low to inhibit charging
current flow to batteries A and B,
respectively.
VCC supply input
5.0 V, ±10% power input.
Ground
2