Smart shutdown function

STIPN2M50-H

12/21

DocID030065 Rev 4

4

Smart shutdown function

The device integrates a comparator for fault sensing purposes. The comparator has an

input on pin (CIN) can be connected to an external shunt resistor for simple overcurrent

protection.

When the comparator triggers, the device is set to the shutdown state and both of its

outputs are set to the low level, causing the half-bridge to enter a tri-state.

In common overcurrent protection architectures, the comparator output is usually

connected to the shutdown input through an RC network so to provide a monostable circuit

which implements a protection time following to a fault condition.

Our smart shutdown architecture immediately turns off the output gate driver in case of

overcurrent through a preferential path for the fault signal which directly switches off the

outputs. The time delay between the fault and output shutdown no longer depends on the

RC values of the external network connected to the shutdown pin. At the same time, the

DMOS connected to the open-drain output (pin T/

SD

̅̅̅̅/OD) is turned on by the internal logic,

which holds it on until the shutdown voltage is well below the minimum value of logic input

threshold (Vil).

Besides, the smart shutdown function allows the real disable time to be increased while the

constant time of the external RC network remains as it is.