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searching better leakage current than ADG701

Hello,

I am searching for a replacement for the ADG701.
There are two relevant points:

1.) Better or equal leakage current.

2.) More than one switch in the package.

It will be used switching gain resistors in a photodiode TIA. See the picture!

I need a flat on resistance which wont disturb the lower 100k and a low leakage for the 10M resistor.

I have done tests with the ADG701 and we are not allowed to get worse with leakage!

I assume that we have some problems with leakage temp drift, so I need a better part.

The ADG701 datasheet has only typical 10pA, but says nothing about min/max oder full temp.

You have several switches which are equal to typ 10pA, but these devices show relatively large currents in the min/max or full temp statement.

I would like to have 2, 3 or 4 switches in one case. So I found the ADG711.

Please tell me, is the leakage better, worse or equall?

I have red that all leakage comes from the ESD diodes on source and drain.
So I assume, that devices made for lower currents have smaller diodes and therefore have lower leakage currents.

True?

Getting better leakage values is more important than the number of switches in one package!

Thanks a lot!

Regards, Kai Toennies

  • Hi Kai Toennies,

    I'm confused, you mentioned 100k and 10M resistor above but looking at your schematic, I don't see any 100k and 10M? I can see 470k and 15M though. Please clarify.

     

    For ADG701 replacement, yes the ADG711 will be suitable for your application requirement: equal leakage current and more than one switch in a package. The ADG711 is a quad SPST switch with low Ron = 2.5 ohms at 5V supply, and has 10pA typ and up to 200pA max of leakage current only.

     

    For leakage, I would not say that it all came from the ESD diodes, it does contribute but leakage is mostly caused by the parasitic in the switch itself.

     

    Let me know if this help.

     

    Best Regards,

    May

  • Hi May,

    Thank you for your assistance!

    The resistor values are not fixed yet. I won't go lower than 100k and I hope not to get larger than 10M, but would like to be able to work with 20M as well.

    That is why I am looking for a switch with better leakage than ADG701.

    Could you provide min max leakage for the ADG701?

    Best Regards,

    Kai

  • Hi Kai,

    The ADG701 was first released way back 1998 and the min and max specs were not characterized before. So unfortunately, the data you are asking for is not available.

    The ADG711 on the other hand, has leakage current min and max specs as low as 10pA typ and up to 200pA and is more suitable for your application requirement: equal leakage current and more than one switch in a package. The ADG711 is also a quad SPST switch with low Ron = 2.5 ohms at 5V supply and is available in 16 ld SOIC and 16 ld TSSOP package.

    Let me know if this helps.

    Best Regards,

    May