420mA current output using XTR111 with offfset input voltages

[PRIYADHARSHINI PALANISAMY]

Here i have enclosed my schematic..please verify it .please suggest me if any correction is required
vin=0.5-4v
I out=4-20mA

 

[FvM]

R4 is almost useless and should be omitted.

The new input range 0.5 - 4 V requires an offset of opposite direction which can't be achieved with the previously discussed circuit. Instead a three resistor voltage divider from 3V and input voltage to the Vin pin may be used. The dimensioning depends on the allowed input load, a buffer amplifier may be necessary.

 

[PRIYADHARSHINI PALANISAMY]

Here i have enclosed my schematic..please verify it .please suggest me if any correction is required
vin=0.5-4v
I out=4-20mA

sorry ..not 0.5-4v
its 0.5-2v

 

[Gorgon]

You are shorting the 3V output to ground(pin5). Remove the GND connection and move the capacitor(C2) to 'REGF' that is the 3V regulator output.
I don't know why you have added R2(0ohm), you can just short pin 4 and 5 to get 3V.

R8 must be removed if you want to distribute your 4-20mA to anywhere. As it is now you are measuring a voltage on the output, so it's Vout not Iout.

 

[PRIYADHARSHINI PALANISAMY]

Thanks
now i have upDated my schematic according to ur suggession.

 

[FvM]

R4 is still useless.

 

[PRIYADHARSHINI PALANISAMY]

Hi,

i have designed the circuit according to your suggestion.it works properly...
i had tried to design 4mA output for 0.4v and 20mA for 2v
so i removed the offset resistor...and placed Rset as 1k
but i get 5.30mA for 0.4v and 21.3mA for 2v
i forgot to solder the 11 th pin(thermal pad to gnd)
is this the reason for wrong output?
or any other issues are there?
thanks in advance