for building a precise and efficient Sample and Hold circuit, i found the following application note in AD website
But the operating voltage range of the op amp used (AD8672) is…
I have a question.
Does AD8676 will occur "phase reversal" when the input voltage exceeds the common mode voltage range within supply voltage range?
Ex. AD8672 D/S Page 1 "No phase reversal"
In this regard, the same as the
Im using the AD8672 on the dual op amp evaluation board to provide 2 output channels.
Both amplifier A and B are given the same 30us input signal. Amplifier A is behaves normally as long as Amplifier B is not connected to a scope (50ohm termination)…
I already destroy more then 10 pcs AD8672 in my experiment.
I just use it as a low noise unit gain buffer.
Supply voltage are +/-12V
IN+ is connected to the reference output from LM399. IN- and output is shorted to provide the negative supply voltage…
There two AD8512 and one AD8672 in the circuit. This image is the first amp after the demodulator.
I need to increase the noise below 100 Hz.
想請問一下我使用AD8672 spice model 去跑Open-Loop Gain and Phase Shift vs. Frequency & Output Impedance vs. Frequency 這兩個參數,RUN出來的參數為何與 DATASHEET上面所標示的是不一樣的,測試條件與Datasheet一樣 , 詳細測試數據在附件,thanks!!!
The OP270 is a very ooooooold part; not recommended for new design.
I would look at using the AD8672.
There is no current limit for the OP270, so it's a function of the output transistors.
I would use 30-40 mA for calculations.
We are using the SPICE model of AD8672 to simulate the open-loop gain & phase shift vs. frequency & output impedance vs. frequency. It turns out to be quite different from the listed in data sheet. Attached is the test result for your information…
Thank you for your reply. I uploaded the screenshot with higher resolution, sorry for that.
I took the headroom as the input voltage where the difference between input and output starts to increase. This is at approximately V+ - 3.5V.