TRIP

TRIP

TRIP

V

(mV)

R

(k )

I

( A)

=

(

)

IN

O

O

TRIP

OCL

DS(ON)

sw

IN

V

V

V

V

= I

R

2

L1

V

æ

ö

-

-

·

·

ç

÷

ç

÷

·

· ¦

è

ø

TPS53114

www.ti.com

SLVS887C – APRIL 2009 – REVISED AUGUST 2014

Feature Description (continued)

8.3.9 Over Current Protection

TPS53114 has a cycle-by-cycle over current limit feature. The over current limits the inductor valley current by

inductor current is larger than the over current limit (OCL), the TPS53114 delays the start of the next switching

provide an accuracy and cost effective solution without external devices. To program the OCL, the TRIP pin

should be connected to GND through a trip voltage setting resistor, according to Equation 1 and Equation 2.

(1)

(2)

The trip voltage should be between 30 mV to 200 mV over all operational temperature, including the

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 TPS53114 will shut down.

8.3.10 Over/under Voltage Protection

TPS53114 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, TPS53114 latches OFF both top and bottom MOSFET drivers. This function is enabled

8.3.11 UVLO Protection

TPS53114 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.

8.3.12 Thermal Shutdown

The TPS53114 includes an over temperature protection shut-down feature. If the TPS53114 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

8.4.1 Operation

The TPS53114 has two operating modes. The TPS53114 is in shut down mode when the EN pin is low. When

the EN pin is pulled high, the TPS53114 enters the normal operating mode.

Copyright © 2009–2014, Texas Instruments Incorporated

Submit Documentation Feedback

11

Product Folder Links: TPS53114