BQ24300 Datasheet, PDF (13/22 Pages) Texas Instruments – OVERVOLTAGE AND OVERCURRENT PROTECTION IC AND Li+ CHARGER FRONT-END PROTECTION IC

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bq24300
bq24304
SLUS764A – AUGUST 2007 – REVISED OCTOBER 2007
Thermal Protection
If the junction temperature of the device exceeds T_J(OFF), FET Q1 is turned off. The FET is turned back on when
the junction temperature falls below T_J(OFF) – T_J(OFF-HYS).
Enable Function
The IC has an enable pin which can be used to enable or disable the device. When the CE pin is driven high, the
internal FET is turned off. When the CE pin is low, the FET is turned on if other conditions are safe. The CE pin
has an internal pull-down resistor of 200 kΩ (typical) and can be left floating.
PGATE Pin
When used with an external P-Channel MOSFET, in addition to OVP, OCP and Battery-OVP, the device offers
protection against input reverse polarity up to –30V. When operating with normal polarity, the IC first turns on
due to current flow through the body-diode of the FET Q_EXT. The PGATE pin then goes low, turning ON Q_EXT.
For input voltages larger than V_GCLMP, the voltage on the PGATE pin is driven to V_IN – V_GCLMP. This ensures that
the gate to source voltage seen by Q_EXT does not exceed –V_GCLMP.
Copyright © 2007, Texas Instruments Incorporated
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