using ne5532 or tl072 for front end

[santlaha]

ne 5532 has many advantages.

1. easily available for use in audio sector
2. 10 mhz bandwith
3. low noise compared to 358
4. 3/5 volt operable.
5. compensated for unity gain

TL072 has similar advantages

1. common
2. 4 MHZ GBP
3. Jfet input
4. low noise
5. 5 volt operable.
6. linear voltage gain upto 500KHZ with 5volt supply.

[fhdm-dev]

I hadn't previously considered the TL072 because I thought the output voltage couldn't swing close enough to the rails but I see the newer version of these chips (the TL07xH family according to the datasheet) can swing to within 100mV - so yeah, that might be worth trying.

[mausi-mick]

I use a MCP6022 (Rail-To-Rail/5V supply) and for voltage-protection the dual-diode BAV199 (low inverse current ) on the non inverting input. For better performance at high frequencies and lower noise I make the feedback-resistor with lower resistance ( 10 k between inverting input and output) . On the ADC('s) of the RP2040
I have a voltage divider from 5V to 3.3V (ca 18k and 33k) .

In the schematic the image from the BAV199 is not correct , the BAV199 is in a SOT23 mpackage.

[mausi-mick]

[fhdm-dev]

Thanks for sharing 😄
I just tried it with an MCP6282 and 1N4148s (the most similar parts I have on hand) and it works a treat.

[mausi-mick]

Nice,
perhaps I can test it in the next days with a MCP 653 (single,r-to-r,sot23-6) with better slew-rate !