Datasheet

TPS54327

SLVSAG1B –DECEMBER 2010–REVISED JUNE 2013

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cycle begins. In subsequent switching cycles, the on-time is set to a fixed value and the current is monitored in

the same manner. If the over current condition exists for 7 consecutive switching cycles, the internal OCL

threshold is set to a lower level, reducing the available output current. When a switching cycle occurs where the

switch current is not above the lower OCL threshold, the counter is reset and the OCL limit is returned to the

higher value.

There are some important considerations for this type of over-current protection. The load current one half of the

peak-to-peak inductor current higher than the over-current threshold. Also when the current is being limited, the

output voltage tends to fall as the demanded load current may be higher than the current available from the

converter. This may cause the output voltage to fall. When the over current condition is removed, the output

voltage will return to the regulated value. This protection is non-latching.

UVLO Protection

Undervoltage lock out protection (UVLO) monitors the voltage of the V

REG5

pin. When the V

REG5

voltage is lower

than UVLO threshold voltage, the TPS54327 is shut off. This is protection is non-latching.

Thermal Shutdown

TPS54327 monitors the temperature of itself. If the temperature exceeds the threshold value (typically 165°C),

the device is shut off. This is non-latch protection.

Product Folder Links: TPS54327