SLVS503F November 2003 – February 2020 TPS2490 , TPS2491
PRODUCTION DATA.
Gate voltage overstress and abnormally large fault current spikes can be caused by large gate capacitance. TI recommends an external gate clamp Zener diode to assist the internal Zener if the total gate capacitance of Q1 exceeds about 4000 pF. When gate capacitor dv/dt control is used, TI recommends a 1-kΩ resistor in series with CG. If the series R-C combination is used for MOSFETs with CISS less than 3000 pF, then a Zener is not necessary.