SLUSEM9A September 2022 – June 2024 UCC21755-Q1
PRODUCTION DATA
To increase the IGBT gate drive current, a noninverting current buffer (such as the NPN/PNP buffer shown in Figure 8-13) can be used. Inverting types are not compatible with the desaturation fault protection circuitry and must be avoided. The MJD44H11/MJD45H11 pair is appropriate for peak currents up to 15 A, the D44VH10/ D45VH10 pair is up to 20-A peak.
In the case of an overcurrent detection, the soft turn-off (STO) is activated. External components must be added to implement STO instead of normal turn-off speed when an external buffer is used. CSTO sets the timing for soft turn-off and RSTO limits the inrush current to below the current rating of the internal FET (10A). RSTO should be at least (VDD-VEE)/10. The soft turn-off timing is determined by the internal current source of 400 mA and the capacitor CSTO. CSTO is calculated using Equation 11.