Current Protection

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TRIP

TRIP

V

( mV )

R

( k

)

( A )

m

=

W ´

(1)

1

2

2

IN

OUT

OUT

TRIP

RIPPLE

TRIP

OCP

DS ( on )

DS ( on )

IN

(V

V

) V

V

I

V

I

R

R

L

f

V

-

´

=

+

=

+

´

´ ´

(2)

Over/Under Voltage Protection

UVLO Protection

Thermal Shutdown

TPS53124

TPS53124 has cycle-by-cycle over current limiting control. The inductor current is monitored during the ‘OFF’

state and the controller keeps the OFF state during the inductor current is larger than the over-current trip level.

In order to provide both good accuracy and cost effective solution, TPS53124 supports temperature

The trip level should be in the range of 30 mV to 200 mV over all operational temperature. The inductor current is

that PGNDx should be connected to the source terminal of the bottom MOSFET.

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.

TPS53124 monitors a resistor divided feedback voltage to detect over and under voltage. When the feedback

voltage becomes higher than 115% of the target voltage, the OVP comparator output goes high and the circuit

latches as the high-side MOSFET driver OFF and the low-side MOSFET driver ON.

When the feedback voltage becomes lower than 70% of the target voltage, the UVP comparator output goes

high and an internal UVP delay counter begins counting. After 30

µs, TPS53124 latches OFF both top and

bottom MOSFET drivers, and shut off both drivers of another channel. This function is enabled approximately 2.0

ms.

TPS53124 has V5FILT Under Voltage Lock Out protection (UVLO). When the V5FILT voltage is lower than

UVLO threshold voltage TPS53124 is shut off. This is non-latch protection.

TPS53124 monitors the temperature of itself. If the temperature exceeds the threshold value (typically 150

°C),

the switchers will be shut off as both DRVH and DRVL at low, the output discharge function enabled. Then

TPS53124 is shut off. This is non-latch protection.

10

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