BQ2003_12 Datasheet, PDF (2/18 Pages) Texas Instruments – Fast-Charge IC

bq2003
Pin Descriptions
TCO
CCMD,
DCMD
DVEN
TM1–
TM2
TS
BAT
Vss
SNS
Charge initiation and discharge-before-
charge control inputs
These two inputs control the conditions that
begin a new charge cycle and enable
discharge-before-charge. See Table 1.
-∆V enable input
This input enales/disables -∆V charge termina-
tion. If DVEN is high, the -∆V test is enabled.
If DVEN is low, -∆V test is disabled. The state
of DVEN may be changed at any time.
Timer mode inputs
MCV
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 sense input
Input, referenced to SNS, for an external
thermistor monitoring battery temperature.
Single-cell voltage input
The battery voltage sense input, referenced
to SNS. This is created by a high-impedance
resistor divider network connected between
the positive and the negative terminals of
the battery.
Ground
Charging current sense input
SNS controls the switching of MOD based on
the voltage across an external sense resistor
in the current path of the battery. 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.
TEMP
CHG
MOD
DIS
VCC
Temperature cutoff threshold input
Input to set maximum allowable battery
temperature. If the potential between TS
and SNS is less than the voltage at the TCO
input, then fast charge or top-off charge is
terminated.
Maximum-Cell-Voltage threshold input
Input to set maximum single-cell equivalent
voltage. If the voltage between BAT and SNS
is greater than or equal to the voltage at the
MCV input, then fast charge or top-off charge
is inhibited.
Note: For valid device operation, the
voltage level on MCV must not exceed
0.6 ∗ VCC.
Temperature status output
Push-pull output indicating temperature
status. TEMP is low if the voltage at the TS
pin is not within the allowed range to start
fast charge.
Charging status output
Push-pull output indicating charging status.
See Figure 1.
Current-switching control output
MOD is a push/pull output that is used to
control the charging current to the battery.
MOD switches high to enable charging cur-
rent flow and low to inhibit charging current
flow.
Discharge FET control output
Push-pull output used to control an external
transistor to discharge the battery before
charging.
VCC supply input
5.0 V, ±10% power input.
2