ZHCSMR1C october 2019 – september 2021 UCC5870-Q1
PRODUCTION DATA
Integrated diodes prevent the OUTH and CLAMP outputs from exceeding VCC2. The short circuit clamping function clamps the voltages at the driver output (OUTH) and active Miller clamp (CLAMP) outputs to be slightly higher than VCC2 during power switch short circuit conditions. The clamped gate voltage limits the short circuit current and prevents the IGBT/MOSFET gate from overvoltage breakdown or degradation. The internal diodes conduct up to 500 mA current for a duration of 10us, and a continuous current of 20mA. Use external Schottky diodes to improve current conduction capability, if needed.
While VCC2 is unpowered, the gate of the external power switch is held off with an active pulldown circuit. If the OUTL suddenly rises due to ramping VCC2 during power up, the active pulldown function pulls the IGBT/MOSFET gate to the low state and maintains the OUTL voltage below VOUTSD. See Figure 7-12 for a drawing of the clamping circuits.