Datasheet

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UNDERVOLTAGE LOCKOUT
TPS65013
SLVS517A – AUGUST 2004 – REVISED JANUARY 2005
The undervoltage lockout circuit for the four regulators on TPS65013 prevents the device from malfunctioning at
low input voltages and from excessive discharge of the battery. Basically, it prevents the converter from turning
on the power switch or rectifier FET under undefined conditions. The undervoltage threshold voltage is set by
default to 2.75 V. After power up, the threshold voltage can be reprogrammed through the serial interface. The
undervoltage lockout comparator compares the voltage on the VCC pin with the UVLO threshold. When the VCC
voltage drops below this threshold, the TPS65013 sets the PWRFAIL pin low and after a time t
(UVLO)
disables the
voltage regulators in the sequence defined by PS_SEQ. The same procedure is followed when the TPS65013
detects that its junction temperature has exceeded the overtemperature threshold, typically 160 ° C, with a delay
t
(overtemp)
. The TPS65013 automatically restarts when the UVLO (or overtemperature) condition is no longer
present.
The battery charger circuit has a separate UVLO circuit with a threshold of typically 2.5 V, which is compared
with the voltage on AC and USB supply pins.
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