ZHCSDD8D October 2014 – December 2019 TPS1H100-Q1
PRODUCTION DATA.
In many conditions, such as the negative ISO pulse, or the loss of battery with an inductive load, a negative potential on the device GND pin may damage the MCU I/O pins [more likely, the internal circuitry connected to the pins]. Therefore, the serial resistors between MCU and HSD are required.
Also, for proper protection against loss of GND, TI recommends 4.7 kΩ when using 3.3-V MCU I/Os; 10 kΩ is for 5-V applications.