5.5 V INPUT, 50 mA SYNCHRONOUS STEP-DOWN SWITCHING REGULATOR WITH 260 nA QUIESCENT CURRENT

S-85S0A Series

10

8. Automatic recovery type short-circuit protection function (Hiccup control)

The S-85S0A Series has a built-in automatic recovery type short-circuit protection function for Hiccup control.

Hiccup control is a method for periodically carrying out automatic recovery when the IC detects overcurrent and

stops the switching operation.

8. 1 When over load status is released

<1> Overcurrent detection

<3> 220

μs elapse

<4> Switching operation stop (for 9 ms typ.)

<5> Overload status release

<6> The IC restarts, soft-start function starts.

In this case, it is unnecessary to input an external reset signal for restart.

<1>

<5>

<2>

<4>

<6>

<3>

<7>

*1

220

s

9.0 ms typ.

1.0 ms typ.

0 A

0 V

0 V

Overload status

Normal load status

*1. Inductor current

Figure 4

8. 2 When over load status continues

<1> Overcurrent detection

<3> 220

μs elapse

<4> Switching operation stop (for 9 ms typ.)

<5> The IC restarts, soft-start function starts.

<6> The status returns to <2> when over load status continues after 1.25 ms typ. elapses.

<1>

<2>

<4>

<5>

<2>

<4>

<3>

<3>

<6>

*1

220

s

220

s

9.0 ms typ.

9.0 ms typ.

1.25 ms typ.

0 A

0 V

0 V

Overload status

*1. Inductor current

Figure 5