STGAP1ASTR datasheet(30/70 Pages) STMICROELECTRONICS

30 / 70 page

Functional description

STGAP1AS

30/70

DocID029344 Rev 2

7.5

Thermal warning and shutdown protection

The device provides a thermal warning and a thermal shutdown protection.

When junction temperature reaches the TWN temperature threshold the TWN flag in the

STATUS1 register is forced high. The TWN flag is released as soon as the junction

temperature is lower than TWN - Thys.

When junction temperature reaches the TSD temperature threshold, the device is forced in

“safe state” and the TSD flag in the STATUS1 register is forced high. The device operation is

restored and the TSD flag is released as soon as the junction temperature is lower than

TSD - Thys.

7.6

Desaturation protection

This feature allows implementing an overload protection for the IGBT. The DESAT pin

monitors the VCE voltage of the IGBT while it is on, and if the protection threshold is

reached, the IGBT is turned off.

When the IGBT is off (GOFF output is activated) the DESAT pin is kept low internally and

the external blanking capacitor connected to the DESAT pin is discharged (the internal

current generator is fully switched off and the switch between DESAT and GNDISO pins is

turned on).

When the GON output is activated the switch between DESAT and GNDISO pins is turned

off and an internal programmable current generator (IDESAT) starts charging the external

blanking capacitor after a fixed blanking time tBLK.

If a desaturation event occurs the VCE voltage increases and the voltage at the DESAT pin

reaches the desaturation threshold VDESATth: the DESAT comparator output is set, the

device is forced in “safe state” and the DESAT flag is forced high and latched.

The DESAT comparator is not active when the external IGBT is off or after desaturation

detection (see Figure 11).

Both the VDESATth threshold and the IDESAT blanking current are programmable through the

SPI.

STGAP1ASTR Datasheet(PDF) 30 Page - STMicroelectronics