I would like to measure the voltage with a voltage divider.
I would like to bias (offset, subtract) 5V with the ADR5045BKSZ-REEL7 from a 6-16V Voltage Source.
My current scheme is this:
I have calcuted that the Total current should be betwwen 75uA (6V Input) and 820uA (16v) Input. Max Voltage Output is about 3.5V, Minimum about 0.3V. (Spannungsteiler, belastet)
I have seen on another post that somebody made a similar circuit with a TL431 variable shunt regulator:
Do you agree that my solution should working?
Thank's very much for every input
I'm sorry. I mean ADC and not DAC. I would like to measure the voltage on the ADC from a stm32 so i need 0-3.3V Input level.
But i think the ADP7182 need also minimum current to operate? Anyway, I have seen that ADP7182 is more than double the price so it is too expensive.
Thank's very much
Yes. excactly. That is my intend. Because the ADR5054 is quite precise and dos not cost very much...
Other solutions tend to be more expensive or more complicated (or use more space).
So nothing wrong with my schema?
Yes, it should be working the same except the TL431 design will have additional current thorugh that 5V/50Kohm.
The voltage drop across the ADR5045 will not suffer from accuracy error of the 50Kohm resistor.
Another option is to use a negative linear regulator such as the ADP7182 set for -5V out. In this case the voltage will always be 5V below Vcc independently of how much current is flowing to Vss. On the ADP7182 you would have 0Vin connected to your GND and GND pin connected to your Vcc
I see you listed the Vss as being a DAC with 0-3V. Is this a DAC you are powering or a DAC you want to use to control the voltage at Vss?
OK I see, you are trying to measure the voltage at Vcc, so a voltage varying from 6V to 16V?
Then the ADR5054 + R1 and R2 will work to maximize your dynamic range.
Correct Andreas, nothing wrong with your design