SLVSDZ9 May 2019 DRV8340-Q1
PRODUCTION DATA.
The goal of this example is to set the VDS monitor to trip at a current greater than 100 A. According to the CSD18536KCS 60 V N-Channel NexFET™ Power MOSFET data sheet, the RDS(on) value is 1.8 times higher at 175°C, and the maximum RDS(on) value at a VGS of 10 V is 1.6 mΩ. From these values, the approximate worst-case value of RDS(on) is 1.8 × 1.6 mΩ = 2.88 mΩ.
Using Equation 9 with a value of 2.88 mΩ for RDS(on) and a worst-case motor current of 100 A, Equation 10 shows the calculated the value of the VDS monitors.
For this example, the value of VDS_OCP was selected as 0.31 V.
The SPI devices allow for adjustment of the deglitch time for the VDS overcurrent monitor. The deglitch time can be set to 2 µs, 4 µs, 6 µs, 8 µs, 10 µs, 12 µs, 16 µs, or 20 µs.