VNB14NV04, VND14NV04, VND14NV04-1, VNS14NV04

Protection features

Doc ID 7393 Rev 9

9/31

3

Protection features

During normal operation, the input pin is electrically connected to the gate of the internal

power MOSFET through a low impedance path.

The device then behaves like a standard power MOSFET and can be used as a switch from

DC up to 50 KHz. The only difference from the user’s standpoint is that a small DC current

The device integrates:

●

Overvoltage clamp protection: internally set at 45 V, along with the rugged avalanche

characteristics of the Power MOSFET stage give this device unrivalled ruggedness and

energy handling capability. This feature is mainly important when driving inductive

loads.

●

voltages. When the current limiter is active, the device operates in the linear region, so

power dissipation may exceed the capability of the heatsink. Both case and junction

temperatures increase, and if this phase lasts long enough, junction temperature may

●

Over temperature and short circuit protection: these are based on sensing the chip

temperature and are not dependent on the input voltage. The location of the sensing

element on the chip in the power stage area ensures fast, accurate detection of the

junction temperature. Over temperature cutout occurs in the range 150 to 190 °C, a

typical value being 170 °C. The device is automatically restarted when the chip

temperature falls of about 15 °C below shutdown temperature.

●

device tries to sink a diagnostic current Igf through the input pin in order to indicate fault

condition. If driven from a low impedance source, this current may be used in order to

warn the control circuit of a device shutdown. If the drive impedance is high enough so

This will not however affect the device operation: no requirement is put on the current

capability of the input pin driver except to be able to supply the normal operation drive

Additional features of this device are ESD protection according to the Human Body model

and the ability to be driven from a TTL Logic circuit.