OPA4197: External Current source design recommendations

Sahil Nayak

Part Number: OPA4197

Hi TI Team,

We are planning to use an ADC for RTD PT1000 measurements with external current source.

Please suggest ways to design a precision current source or let us know if any ready made small size and low cost solution is available.

Thanks & Regards,
Sahil Nayak

0 Art Kay 8 months ago

Sahil,

RTD to Voltage Reference Design Using Instrumentation Amplifier and Current Reference shows an example of REF200 (integrated current reference) driving an RTD. REF200 is the "ready made" option.
Low Level (5 µA) V-to-I Converter shows a high accuracy current source. May be overkill for your purposes.
MAKE A PRECISION CURRENT SOURCE OR CURRENT SINK is a simple current source using a voltage reference and op amp. This is really simple and would work for your application.
Precision Current Sources and Sinks Using Voltage References is a document that covers multiple different current sources. Good for higher current outputs but could work for your application.
“Improved” Howland current pump circuit is the Holland current pump. This is the most popular current source, and would work well in your application.

Best regards,

Art

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