PicoScope 7 Software
Available on Windows, Mac and Linux
Measure/calculate CMRR of Audio Opamp
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grievousangel
- Newbie
- Posts: 1
- Joined: Wed Oct 02, 2019 8:57 am
- Location: SE Georgia, USA
Measure/calculate CMRR of Audio Opamp
I have a Picoscope 4262 and need to adjust the CMRR of an audio amp. The amp is a discrete DOA similar to SL-2520 as used in API-like studio gear.
Would differential probes help with these procedure? CMRR application notes?
Advice please.
Later.
Billy
Would differential probes help with these procedure? CMRR application notes?
Advice please.
Later.
Billy
GrievousAngel
Picoscope 4262
Picoscope 4262
Re: Measure/calculate CMRR of Audio Opamp
Hi grievousangel,
I apologise for the delay in answering (this post got overlooked in the run up to Christmas).
For the precision that I assume you will be working with, you would probably need a low voltage active differential probe (to help probe relatively small, non-earth referenced voltages). The lowest voltage, probe less than £500 in our product line-up would be this x10 probe: https://www.picotech.com/accessories/hi ... tial-probe. So the answer to your question depends upon the precision with which you need to adjust the CMRR.
In all likelihood, a better solution would probably be to use a suitable differential Instrumentation amplifier module to condition the signal for the PicoScope 4262. Finding suitable Instrumentation diff-amp modules from reputable manufacturers that would be suitable for test and Measurement is a challenging task, but it is made easier by the likes of Analog Devices and Texas Instruments offering cost effective Instrumentation amplifier modules, such as this one: https://www.digikey.com/en/products/det ... VM/2762244, some of which you can even purchase already populated (note that this is just a suggestion, as we have not verified any such devices for any specific use with our products).
Regards,
Gerry
I apologise for the delay in answering (this post got overlooked in the run up to Christmas).
For the precision that I assume you will be working with, you would probably need a low voltage active differential probe (to help probe relatively small, non-earth referenced voltages). The lowest voltage, probe less than £500 in our product line-up would be this x10 probe: https://www.picotech.com/accessories/hi ... tial-probe. So the answer to your question depends upon the precision with which you need to adjust the CMRR.
In all likelihood, a better solution would probably be to use a suitable differential Instrumentation amplifier module to condition the signal for the PicoScope 4262. Finding suitable Instrumentation diff-amp modules from reputable manufacturers that would be suitable for test and Measurement is a challenging task, but it is made easier by the likes of Analog Devices and Texas Instruments offering cost effective Instrumentation amplifier modules, such as this one: https://www.digikey.com/en/products/det ... VM/2762244, some of which you can even purchase already populated (note that this is just a suggestion, as we have not verified any such devices for any specific use with our products).
Regards,
Gerry
Gerry
Technical Specialist
Technical Specialist