BQ294602 Datasheet, PDF (3/17 Pages) Texas Instruments – Single-Cell Protector for Li-Ion Batteries

bq294602, bq294604
www.ti.com
PIN FUNCTIONS
bq2946xy
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Thermal Pad
Pin Name
NC
V1
VSS
VSS
VDD
OUT
PWRPAD
SLUSAS0B – DECEMBER 2011 – REVISED MARCH 2012
Type I/O
—
IA
P
P
P
OA
—
Description
No Connection
Sense input for positive voltage of the cell
Electrically connected to IC ground and negative terminal of the
cell
Electrically connected to IC ground and negative terminal of the
cell
Power supply
Output drive for external N-Channel FET
VSS pin to be connected to the PWRPAD on the printed circuit
board for proper operation
PIN DETAILS
Description
The method of overvoltage detection is comparing the cell voltage to an overvoltage protection threshold voltage
V_OV. Once the cell voltage exceeds the programmed fixed value V_OV, the delay timer circuit is activated. This
delay (t_DELAY) is fixed for 4 s for the bq294602 device. When these conditions are satisfied, the OUT terminal is
transitioned to a high level. This output (OUT) is released to a low condition if the cell input (V1) is below the
OVP threshold minus the V_HYS.
VOV
VOV – VHYS
OUT (V)
t DELAY
Figure 1. Timing for Overvoltage Sensing
Sense Positive Input for V1
This is an input to sense single battery cell voltage. A series resistor and a capacitor across the cell is required
for noise filtering and stable voltage monitoring.
Output Drive, OUT
The gate of an external N-Channel MOSFET is connected to this terminal. This output transitions to a high level
when an overvoltage condition is detected and after the programmed delay timer. The out will reset to a low level
if the cell voltage falls below the V_OV threshold before the fixed delay timer expires.
Supply Input, VDD
This terminal is the unregulated input power source for the IC. A series resistor is connected to limit the current,
and a capacitor is connected to ground for noise filtering.
Thermal Pad, PWRPAD
For correct operation, the power pad (PWRPAD) is connected to the V_SS terminal on the printed circuit board.
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