Continue to Site

Welcome to

Welcome to our site! is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

AS331 comparator has ESD diodes from each pin to Vcc and Gnd?

If it's a straight rip-off of LM331 then it may not have any ESD circuitry at all. Old standard linear bipolar parts just "took their lumps", lacking thin oxides and having large device sizes.

* in the absolute maximum input voltage .. they don´t refer to VCC, but to an absolute voltage of 40V.
* in the "functional block diagram" there are no diodes. (Although "functional" does not necessarily include "protection". And I personally see it as "simplified" schematic)
* it seems a purely bipolar circuit .. which is not that critical on ESD ...

.. this all makes me guess there are no ESD protection diodes at all. But the datasheet is not absolutely clear in this regard.
The guts look like a 1-channel LM139. Nothing but a bare lateral PNP base contact at the input pins (and a back diode to help with "soft ESD" hot carrier drift). But by their nature the LPNP base also has the fat tank-iso junction which is fortunate for negative-going ESD and somewhat robust (@60V or so breakover) positive avalanche.

You can expect Class 1 ESD ruggedness. Not much, but whaddyawantfernuthin' ?

LaTeX Commands Quick-Menu:

Similar threads

Part and Inventory Search

Welcome to