Current input with higher capacity than DDC232

Patrick Sheridan

Other Parts Discussed in Thread: DDC232, DDC112

I'm looking for a chip that has functionality similar to the DDC232, namely:

Multichannel (>16), virtual-ground current integrators with integrated ADCs.

The problem is that the full scale range on the DDC232 is 350pC and with a minimum integration time of 50us, this corresponds to maximum current of 7uA. I'm looking for something that can handle ~70uA or more.

Any suggestions would be appreciated.

over 9 years ago

0 Adam Sidelsky over 9 years ago

TI__Guru 65430 points

Patrick,

Thanks for contacting TI. I am Adam Sidelsky, applications support for the DDC line of products.

At the moment the DDC232 range of 350pC is the maximum we have for >16 channel applications. We have the lower channel count DDC112 (2-channel) which allows for external integration capacitors and up to 1000pC range. Unfortunately this is still low for your request.

What is the application?

Regards,

-Adam

0 Patrick Sheridan over 9 years ago in reply to Adam Sidelsky

Prodigy 30 points

I would be using it for a memory array test and measurement tool. Do you know of any AFE's perhaps without the integrated ADC (i.e. analog output) that would offer this functionality? Or perhaps a multichannel current shunt AFE? Thanks, Patrick

0 Adam Sidelsky over 9 years ago in reply to Patrick Sheridan

TI__Guru 65430 points

Unfortunately I'm not aware of those devices. I can ask if someone here has a recommendation.

0 Eduardo Bartolome over 9 years ago in reply to Adam Sidelsky

TI__Expert 4680 points

Hi,

I am not familiar either with other devices, but I have seen folks use a resistor divider at the inputs. This, besides increasing the footprint, does degrade noise and linearity but if there is room in the performance to accept some degradation...

Regards,

Edu

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Current input with higher capacity than DDC232