Datasheet

TRCKn

SW NODE

VOUT

COMP

ILIM

2.4 V

1.5 V

0.5 V

GND

VIN

GND

VOUT, REG

GND

t0 t1 t2 t3

(A)

(B)

(C)

(D)

TPS40140

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SLUS660H –SEPTEMBER 2005–REVISED JUNE 2013

High bandwidth current amplifiers, U2 and U21 can accept as an input voltage either the voltage drop

across dedicated precise current sense resistors, or inductor’s DCR voltage derived by an RC network, or

thermally compensated voltage derived from the inductor’s DCR. The wide range of current sense

arrangements ease the cost/complexity constrains and provides superior performance compared to

controllers utilizing the low-side MOSFET current sensing.

See the Inductor DCR Current Sense section for selecting the values of the RC network.

5.25 OVERCURRENT DETECTION AND HICCUP MODE

In order to reduce the input current and component dissipation during on overcurrent event, a hiccup

mode is implemented. Hiccup mode refers to a sequence of 7 soft-start cycles where no MOSFET

switching occurs and then a re-start is attempted. If the fault has cleared, the re-start results in returning to

normal operation and regulation. This is shown in Figure 5-9.

Figure 5-9. Hiccup Mode and Recovery

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