TPS53211_15 Datasheet, PDF (10/22 Pages) Texas Instruments – Single-Phase PWM Controller with Light-Load Efficiency Optimization

TPS53211
SLUSAA9A – SEPTEMBER 2011 – REVISED NOVEMBER 2012
www.ti.com
The TPS53211 has thermal compensation to adjust the OCP threshold in order to reduce the influence of
inductor DCR variation due to temperature change. The OCP level has a change rate of 0.35%/°C.
Overvoltage and Undervoltage Protection
The TPS53211 monitors the VSEN pin voltage to detect the overvoltage and undervoltage conditions. A resistor
divider with the same ratio as on the FB input is recommended for the VSEN input. The overvoltage and
undervoltage thresholds are set to ±13% of V_OUT.
When the VSEN voltage is greater than 113% of the reference, the overvoltage protection is activated. The high-
side MOSFET turns off and the low-side MOSFET turns on. Normal operation can be restored only by cycling the
VCC pin voltage.
When the VSEN voltage is lower than 87% of the reference voltage, the undervoltage protection is triggered and
the PGOOD signal goes low. After 80 µs, the controller is latched off with both the upper and lower MOSFETs
turned off.
After both the undervoltage and overvoltage events, the device is latched off. Normal operation can be restored
only by cycling the VCC pin voltage.
Power Good
The TPS53211 monitors the output voltage through the VSEN. During start up, the power good signal delay after
the reference begins to rise is 1560 clock cycles. After this delay, if the output voltage is within ±9.5% of the
target value, PGOOD signal goes high.
At steady state, if the VSEN voltage is within 113% and 87% of the reference voltage, the power good signal
remains high. If VSEN voltage is outside of this limit, PGOOD pin is pulled low by the internal open drain output.
The PGOOD output is an open drain and requires an external pull-up resistor.
Over-Temperature Protection
The TPS53211 continuously monitors the die temperature. If the die temperature exceeds the threshold value
(140˚C typical), the device shuts off. When the device temperature lowers to 40˚C below the over-temperature
threshold, it restarts and return to normal operation.
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