STHV748 output protection.

serghei · ‎2016-04-26

Posted on April 27, 2016 at 08:30

Hi! In my project I use STHV748. Pulser works with cable (50 Ohm) >10m long. To protect IC outputs from overvoltage I use next schematic. It is right? Can you recomend another variant?

#sthv748-output-protection

ricciardo.antonio · ‎2016-06-29

Posted on June 29, 2016 at 13:37

Hello, Serghei,

So the first suggestion in a way to protect the IC from overvoltage and surge currents reflected by cable could be to use the STHV748

S

instead of STHV748 first generation of ST pulser.

STHV748S is self-protected by current reflection load thanks to a new HV diodes network integrated on each XDCR output, basically we have improved the internal ESD network to withstand and make robust the pulser for this overvoltage phenomena.

STHV748S is pin compatible one-to-one with STHV748 even for truth table keeping the same functions.

With regards your selection for external protection SM6T100A/CA, for sure it can be useful to clamp and take surge current away through external SM6T but in my opinion it's critical the speed (Time to respond) of this part, because likely the ESD diodes integrated are more fast to intervene respect SM6T diodes. Alternative for SM6T you should consider more fast BAV23 series to connect to XDCR#.

Please let us know your thoughts

Best

Antonio Ricciardo

ayarema · ‎2017-11-16

Posted on November 17, 2017 at 04:45

When will the STHV748S be available for order? No distributor has any stock at this point.