INA188: 4-20mA input with Active mode

Cyril Vidal

Prodigy 100 points

Part Number: INA188
Other Parts Discussed in Thread: LM7705

is it possible to use IN188 to make an active 4-20mA inout ?

And to only power supply it in 0V-24V .

See diagramm below :

over 4 years ago

0 kai klaas69 over 4 years ago

Guru 140200 points

Hi Cyril,

no, it will not work because in both cases the input signal would exceed the common mode input voltage range:

Kai

0 Cyril Vidal over 4 years ago in reply to kai klaas69

Prodigy 100 points

Hi,

I have to put an offset to work in this case ?

If yes, how can I make this offset ?

0 kai klaas69 over 4 years ago in reply to Cyril Vidal

Guru 140200 points

Hi Cyril,

your information is a bit confusing. Is it 4...20mA or +/-20mA or 0...20mA?

You will need to connect a negative supply voltage to the V- pin of INA188. Depending on your input signal current, a LM7705 might eventually be sufficient.

Kai

0 Cyril Vidal over 4 years ago in reply to kai klaas69

Prodigy 100 points

Hi,

it is for 0....20mA & 0---10V only.

but as VCM spécification is (VS-)+0.1V. I think i need a offset. isn't it ?

Thanks

0 kai klaas69 over 4 years ago in reply to Cyril Vidal

Guru 140200 points

Hi Cyril,

then a negative supply voltage of -1.5V could be used:

Kai

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INA188: 4-20mA input with Active mode