HSP051-4M10 on STM32MP257-DK board?

[HMüll.4]

Hi,

just a quick question to understand the hardware of the STM32MP257 development kit board: there are several ESD-protection components of type HSP051-4M10 used.

What is the exact purpose of them, are they there

a) because the DK-board is intended to be touched by users and therefore there is some higher danger these users kill that board with some electrostatic discharge when touching it

b) because this type of device is recommended to be used in general due to some components being unusual sensitive against ESD (for an example, at the RasPi I think no such protection is used)

c) something else?

Thanks for sheding some light on this :)

 

[Peter BENSCH]

Short answer: a) and b)

In detail: it is always advisable to protect signal lines leading to the outside against ESD, because normal electronic devices have no explicit ESD protection. There are of course exceptions, e.g. specially designed RS-485 transceivers.

The Raspberry Pi was originally developed for teaching at schools and universities. If no ESD protection is provided in the Raspi (I didn't checked it), this can be described as extremely careless and by no means a reference for a reliable industrial design.

Regards
/Peter