L6376

Short circuit operation

11/18

8

Short circuit operation

In order to allow normal operation of the other inputs when one channel is in short cirtuit, an

innovative non dissipative over current protection (patent pending) is implemented in the

device.

In this way, the temperature of the device is kept enough low to prevent the intervention of

the thermal protection (in most of the cases) and so to avoid the shut down of the whole

device.

If a short circuit condition is present on one output, the current limiting circuit puts that

channel in linear mode — sourcing the ISC current (typically 800 mA) — for a time period

After that period, if the short circuit condition is still present the output is turned off for

OFF DELAY pin).

When also this period is expired:

●

if the short circuit condition is still present the output stays on for the tON period and the

sequence starts again;

●

if the short circuit condition is not present anymore the normal operation of the output is

resumed.

using external capacitors ranging from 50 pF to 15 nF (1.28

µs/pF).

The diagnostic output (DIAG) is active when the output is switched off, while it is not active

condition is present.

Figure 5.

Short circuit operation waveforms

OUTPUT

CURRENT

Time

DIAG

(active low)

Time

Short Circuit

Short Circuit

Isc

Iout

D94IN105