I want to use AD815 in inverting configuration with gain of -2. Is 2k and 1k ohm a good choice?
AD815 is a current feedback amplifier and usually, resistors for gain settings are recommended in the datasheet for optimum performance of the device. "For every CFB op amp there is a recommended value of feedback resistor for maximum bandwidth. If you increase the value of the resistor beyond this value, you reduce the bandwidth. If you use a lower value of resistor below this value, the phase margin is reduced, and the amplifier may become unstable." - excerpt from MT-034:Current Feedback (CFB) Op Amps
I would suggest start to choose the recommended RF in the datasheet first and then select another resistor to yield the closed-loop gain you desired. For example, for the closed gain of -2, you can start with 499 ohms and pick 249 ohms to get your desired closed loop gain.
Thanks Phil for response.
I am curious to know how sensitive is frequency response to these resistor values.
I am using AD815 in unity feedback with 552ohm ( instead of 562ohm) in non-inverting config same as data sheet. I have few degrees phase delay in 19vpp output swing with and without load of 120ohm or 60 ohm.
btw, I am at 1MHz.
My application is transducer excitation for ultrasonic beamforming.
Please reply my previous questions.
Also, I need to know how I can measure my AD815 power consumption when I deliver 60vpp output signal to my 75ohm transducer in differential mode ( max current delivery of .4A to my load from each amp). Schematic is below.).
Just a quick question.Would it be okay if you could share your application for this device.
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