Datasheet

TPS2560
TPS2561
www.ti.com SLVS930A –DECEMBER 2009– REVISED FEBRUARY 2012
FAULTx RESPONSE
The FAULTx open-drain outputs are asserted (active low) on an individual channel during an overcurrent or
overtemperature condition. The TPS2560/61 asserts the FAULTx signal until the fault condition is removed and
the device resumes normal operation on that channel. The TPS2560/61 is designed to eliminate false FAULTx
reporting by using an internal delay "deglitch" circuit (9-ms typ) for overcurrent conditions without the need for
external circuitry. This ensures that FAULTx is not accidentally asserted due to normal operation such as starting
into a heavy capacitive load. The deglitch circuitry delays entering and leaving current-limited induced fault
conditions. The FAULTx signal is not deglitched when the MOSFET is disabled due to an overtemperature
condition but is deglitched after the device has cooled and begins to turn on. This unidrectional deglitch prevents
FAULTx oscillation during an overtemperature event.
UNDERVOLTAGE LOCKOUT (UVLO)
The undervoltage lockout (UVLO) circuit disables the power switch until the input voltage reaches the UVLO
turn-on threshold. Built-in hysteresis prevents unwanted on/off cycling due to input voltage droop during turn on.
ENABLE (ENx OR ENx)
The logic enables control the power switches and device supply current. The supply current is reduced to less
than 2-μA when a logic high is present on ENx or when a logic low is present on ENx. A logic low input on ENx
or a logic high input on ENx enables the driver, control circuits, and power switches. The enable inputs are
compatible with both TTL and CMOS logic levels.
THERMAL SENSE
The TPS2560/61 self protects by using two independent thermal sensing circuits that monitor the operating
temperature of the power switch and disable operation if the temperature exceeds recommended operating
conditions. Each channel of the TPS2560/61 operates in constant-current mode during an overcurrent conditions,
which increases the voltage drop across the power switch. The power dissipation in the package is proportional
to the voltage drop across the power switch, which increases the junction temperature during an overcurrent
condition. The first thermal sensor (OTSD) turns off the individual power switch channel when the die
temperature exceeds 135°C (min) and the channel is in current limit. Hysteresis is built into the thermal sensor,
and the switch turns on after the device has cooled approximately 20°C.
The TPS2560/61 also has a second ambient thermal sensor (OTSD2). The ambient thermal sensor turns off both
power switch channels when the die temperature exceeds 155°C (min) regardless of whether the power switch
channels are in current limit and will turn on the power switches after the device has cooled approximately 20°C.
The TPS2560/61 continues to cycle off and on until the fault is removed.
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Product Folder Link(s): TPS2560 TPS2561