LA5724MC

No.A2021-4/6

Protection Circuit Functional Descriptions

Overcurrent protection function

The overcurrent protection function detects, on a pulse-by-pulse basis, the output transistor current and turns off that

output transistor current if it exceeds 0.7A in a pulse-by-pulse manner.

Short circuit protection function

This IC prevents the current from increasing when the outputs are shorted by setting the switching frequency to

30kHz if the VOS pin voltage falls below 0.8V.

Note : At startup, since the switching frequency will be 30kHz while the VOS pin voltage is 0.8Vor lower, the

current capacity is reduced. If the load is applied at startup and the applications has trouble starting, increase

the value of the inductor to resolve this problem.

Timing Chart

Limit current

Inductor current

SWOUT voltage

0V

0.8V

1.23V

30kHz

160kHz

VIN voltage

SWOUT voltage

VOS voltage