Smart shut down function

L6390

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Smart shut down function

L6390 integrates a comparator committed to the fault sensing function. The comparator has

input is available on pin 10. The comparator input can be connected to an external shunt

resistor in order to implement a simple over-current detection function. The output signal of

the comparator is fed to an integrated MOSFET with the open drain output available on pin

2, shared with the SD input. When the comparator triggers, the device is set in shut down

state and both its outputs are set to low level leaving the half-bridge in tri-state.

Figure 5.

Smart shut down timing waveforms

HIN/LIN

HVG/LVG

SD/OD

open drain gate

(internal)

upper

threshold

lower

threshold

comp

Vref

CP+

PROTECTION

Fast shut down:

the driver outputs are set in SD state

immediately after the comparator

triggering even if the SD signal

has not yet reach

the lower input threshold

real disable time

2

1

1

2

SD/OD

FROM/TO

CONTROLLER

SMART

SD

LOGIC

SHUT DOWN CIRCUIT

TIME CONSTANTS