Eugen_E
Full Member level 6
max232 op amp power
Hello,
I need to make a radio(HF)<->PC interface powered on USB, and I use a double opamp, LM833, to make a differential amplifier. The opamp output goes to PC souncard - Line In, for signal processing.
Because the opamp needs positive and negative supply, and USB has only 5V, I thought I can use MAX232 or MAX202 circuit to generate ±10V.
I try to avoid using an low voltage, low noise, rail to rail opamp, because I cant find one localy. LM358 is quite noisy.
I want to ask if MAX232, MAX202 - being a switching source will interfere badly with the RF portion of the radio, or if it will generate parasitic signals at the opamp output.
I will use an RC filter on the opamp power lines (V+, V-), and the opamp PSRR is quite high (though it is measured at low frequencies).
So, if someone used MAX232/202 in a radio or high performance audio circuit, please share your opinion on this application.
Thanks
Hello,
I need to make a radio(HF)<->PC interface powered on USB, and I use a double opamp, LM833, to make a differential amplifier. The opamp output goes to PC souncard - Line In, for signal processing.
Because the opamp needs positive and negative supply, and USB has only 5V, I thought I can use MAX232 or MAX202 circuit to generate ±10V.
I try to avoid using an low voltage, low noise, rail to rail opamp, because I cant find one localy. LM358 is quite noisy.
I want to ask if MAX232, MAX202 - being a switching source will interfere badly with the RF portion of the radio, or if it will generate parasitic signals at the opamp output.
I will use an RC filter on the opamp power lines (V+, V-), and the opamp PSRR is quite high (though it is measured at low frequencies).
So, if someone used MAX232/202 in a radio or high performance audio circuit, please share your opinion on this application.
Thanks