L6725 - L6725A

Device description

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5.9

Hiccup mode

the OCH comparator triggers an over current the high-side MOSFET(s) is immediately turned

OFF (after the masking time and the internal delay) and returned on at the next pwm cycle. The

because during the masking time the peak-current-protection is disabled. In case of very hard

is very helpful in this case to limit the current. If during the off-time the OCL comparator triggers

an over current, the high-side MOSFET(s) is not turned on until the current is over the valley-

current-limit. This implies that, if it is necessary, some pulses of the high-side MOSFET(s) will

be skipped, guaranteeing a maximum current due to the following formula:

5.10

Thermal shutdown

When the junction temperature reaches 150°C ±10°C the device enters in thermal shutdown.

Both MOSFETs are turned OFF and the soft-start capacitor is rapidly discharged with an

internal switch. The device does not restart until the junction temperature goes down to 120°C

and, in any case, until the voltage at the soft-start pin reaches 500mV.

Figure 9.

Constant current and Hiccup Mode during an OCP.

VSS

VCOMP

MIN

ON

VALLEY

MAX

T

L

Vout

Vin

I

I

,

⋅

−

+

=

(1)