TPS53127_15 Datasheet, PDF (12/30 Pages) Texas Instruments – TPS53127 Dual Synchronous Step-Down Controller For Low Voltage Power Rails

TPS53127
SLVSA93A – MARCH 2010 – REVISED AUGUST 2014
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Feature Description (continued)
The trip voltage should be between 30 mV to 300 mV over all operational temperature, including the 4000-
ppm/°C temperature slope compensation for the temperature dependency of the R_DS(ON).
If the load current exceeds the over current limit, the voltage will begin to drop. If the over current conditions
continues the output voltage will fall below the under voltage protection threshold and the TPS53127 will shut
down.
In an over current condition, the current to the load exceeds the current to the output capacitor; thus the output
voltage tends to fall off. Eventually, it will end up with crossing the under voltage protection threshold and
shutdown.
8.3.9 Over/Under Voltage Protection
TPS53127 monitors a resistor divided feedback voltage to detect over and under voltage. If the feedback voltage
is higher than 115% of the reference voltage, the OVP comparator output goes high and the circuit latches the
high-side MOSFET driver OFF and the low-side MOSFET driver ON.
When the feedback voltage is lower than 70% of the reference voltage, the UVP comparator output goes high
and an internal UVP delay counter begins counting. After 30 μs, TPS53127 latches OFF both top and bottom
MOSFET drivers. This function is enabled approximately 1.7 x T_SS after power-on. The OVP and UVP latch off is
reset when EN goes low level.
8.3.10 UVLO Protection
TPS53127 has V5FILT under voltage lock out protection (UVLO) that monitors the voltage of V5FILT pin.
When the V5FILT voltage is lower than UVLO threshold voltage, the device is shut off. All output drivers are OFF
and output discharge is ON. The UVLO is non-latch protection.
8.3.11 Thermal Shutdown
The TPS53127 includes an over temperature protection shut-down feature. If the TPS53127 die temperature
exceeds the OTP threshold (typically 150°C), both the high-side and low-side drivers are shut off, the output
voltage discharge function is enabled and then the device is shut off until the die temperature drops. Thermal
shutdown is a non-latch protection.
8.4 Device Functional Modes
The TPS53127 has two operating modes. The TPS53127 is in shut down mode when the EN1 and EN2 pins are
low. When the EN1 and EN2 pins is pulled high, the TPS53127 enters the normal operating mode.
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