AD8017 is configured for use on signle +5 V power supply. It is used for inverting(unity gain) the input signal. Rf = 619 ohms and Rg = 619 ohms. Rt = 52 ohms. The positive terminal(pin no 3) is connected to ground.
When an input signal (DC) voltage of 1.9 V to 0.9 V is applied at Rg(one end) to the above circuit, the output at pin no 1 observed is 140 mV constant.
Kindly clarify / provide a solution.
As far as I understand, you applied positive input voltage; you use inverting configuration, therefore output voltage must be negative. But the most minimal voltage which an op-amp can provide in this case is 0 V (ground potential). You have saturating of output stage.
I hope that this help you.
As understood from above, AD8017 cannot be used in inverting mode with single +5 V supply. Is it right?
Application requirement : AD8017 is used for inverting an incoming signal in the range of 2.1 to 0.6 V pulse. The expected output is a pulse with an amplitude of 1.5 V and any DC offset between 0.6 to 1.0 V, pulse needs to be inverted.
Anjan Kumar N
Hi Anjan Kumar,
You can use any op-amp in inverting mode at single supply, but you should determine limitations of op-amp which will limit specifications of your circuit.
Please, look at datasheet:
This is your case
We can derive the range for output voltage swing using minimum value from datasheet:
If you need single supply configuration you should provide linear region for output stage working. If input voltage increases output voltage decreases or if input voltage decreases output voltage increases respectively. But in any case output voltage should be in output voltage swing range for excluding saturation of output stage.
In this example I applying voltage from voltage divider to non-inverting input, but you can use any other method. Transfer function of this circuit:
Anjan said:The expected output is a pulse with an amplitude of 1.5 V and any DC offset between 0.6 to 1.0 V
Note that output voltage cannot be less than 0.85 V and over than 4.15 V otherwise output stage out of linear mode:
This meets your requirements?
Thanks for the reply, This meets the requirements