RCV420: I-V conversion

Prajwal Bhuse

Part Number: RCV420
Other Parts Discussed in Thread: TLV333

Tool/software:

Dear Team,

I'm designing a current to voltage converter. I'm having the attached one which was suggested by TI fellows but for now, I required few changes in the input as well as output

forum_5-9-24b_tlv333 - autosave 24-06-01 10_40 - autosave 24-07-08 14_04.TSC

the attached I-V converter having input current of 4-20mA and output voltage of 100mV-4.9v.

How can i achieve 1V output for 4mA and 4.9/5V for 20mA. 5V output voltage for 20mA input current is preferred.

Kindly check this and let me know.

Hoping to hear from you soon.

Thanks and Regards,

Mr. Prajwal P. Bhuse

29 days ago

+1 Luis Chioye 28 days ago

TI__Guru 51266 points

Hi Mr. Prajwal,

Scaling the Rsense resistor to 250Ω will produce a 1V output for 4mA and 5V for 20mA. Therefore, the TLV333 will be set in the buffer configuration (non-inverting, unity gain) configuration.

Please note that any rail-to-rail input/output operational amplifier will still need a supply slightly larger than +5V to reach an exact/accurate 5V output.

The TLV333 output requires more than >30mV headroom from the positive and negative supply rails per the "Voltage output swing from rail" specification on page 8 of the data sheet. Using a V+ supply in the range of +5.1V < V+ < +5.5V will provide the expected results. At the OPA input, use a TVS diode with a working voltage of ~5.0V and a clamping voltage slightly above this voltage. I added a series resistor at the non-inverting op-amp input for protection.

See simulation and circuit below.

Thank you and Best Regards,

Luis

TINA Simulation file:

forum_7-5-24_tlv333.TSC