I'm using the ISL70444 and suspect that it is oscillating. I have a 100 resistor between the output and the - input.
It is operating as a unity gain amplifier.
The load is approximately 5 kOhms and the output capacitance is small, just the parasitic capacitance of the trace from the op-amp output to ground which is less than 5 pF.
Would you help me understand Figure 39, from the ISL70444 data sheet, shown below? What gain is implied here?
I would like to get more phase margin by now operating the ISL70444 at a gain of 2 instead of at a gain of 1.
I would like to use a 10 kOhm resistor to reduce the current draw. However, Figure 39 implies that with a 10 kOhm feedback resistor I would see more than 10 dB of gain peaking?
With 10 dB of peaking the phase margin would be quite low, the op-amp would be bordering on being unstable.
Hello Ken,
We apologize but we cannot answer questions on a public forum for our space parts unless the information is already posted on our public website. In this case, your questions will require support from the apps engineer who is responsible for this product.
For any further support on this you will need to submit a Technical Support ticket by going to our support portal from the following link: https://en-support.renesas.com
You already have an account there and we have answered numerous tickets for you in the past.
Best regards, Cindy Huberty, Renesas Electronics, Online Applications Support Engineer