Under Sampling ADC

Aishik Acharya

Other Parts Discussed in Thread: ADC12040, ADC14L040, ADC14L020, ADC141S626, ADS850

Hi,

Can any one suggest me what will be the proper choice of ADCs for sub sampling of a 5MHz signal with 100KHz signal with 14 or higher bit resolution?

I have tried with ADC12040 but the converted signal is very jittery.

Please help.

over 9 years ago

0 Joshua Carnes over 9 years ago

TI__Expert 4340 points

Can you please be more specific about your performance requirements, and perhaps further quantify how the ADC12040 did not meet your requirments?

At this time, I might recommend the ADC14L020 or ADC14L040

Thanks, Josh

0 Aishik Acharya over 9 years ago in reply to Joshua Carnes

Prodigy 40 points

Thank you for the reply. Will ADC14L20 be capable of handling 100KHz clock signal with input signal of 5MHz?

0 Joshua Carnes over 9 years ago in reply to Aishik Acharya

TI__Expert 4340 points

Ah, I misunderstood your sampling rate requirement. No, the ADC14L020 cannot sample at 100kSPS.

It looks like the ADC141S626 could be a very good fit for you. Please have a look. It can sample at 100k, has >20MHz input BW, low power, and has an EVM option.

Regards, Josh

0 Aishik Acharya over 9 years ago in reply to Joshua Carnes

Prodigy 40 points

Thank you Josh. But I want to under-sample a 5MHz signal by a clock of 100KHz.. So my ADC must have some sample and hold circuit. I want a 14bit ADC like ADS850. But Evaluation boards are not available for that. So please can you suggest something like that?

Thanking you

Aishik

0 Joshua Carnes over 9 years ago in reply to Aishik Acharya

TI__Expert 4340 points

Aishik,
The ADC141S626 does sample at 100kSPS and it has a sample and hold circuit. Is the problem that the input clock to the device is a much higher frequency?
Your sampling rate requirement does put you in a tough spot because most devices with eval boards at that speed are precision products where the input clock to the device is not the same frequency as the sampling rate because the data is serialized at the output.
Regards, Josh

0 Aishik Acharya over 9 years ago in reply to Joshua Carnes

Prodigy 40 points

Hi Josh,

Sorry for the delay in reply as I was away. Is ADC141s626 capable of sampling a 5 MHz signal @100KHz clock. My target is undersample 5MHz with a clock of 100KHz.

0 Joshua Carnes over 9 years ago in reply to Aishik Acharya

TI__Expert 4340 points

The sampling rate range of the ADC141s626 is 50-250kHz and the input BW is ~26MHz.
Regards, Josh

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Under Sampling ADC