I am progressing on a medium speed oscilloscope project (targeting ability to show 10~20 MHz signals). On analog front end there is a lot of signal control to cater for
- Different Signal Voltage (compensated step attenuator)
- AD/DC coupling
- Op Amp Gain Control
- Bias Control
The research I have done to date has pointed me to using reed relays to control where the signal goes given the settings input. While there is quite a bit of positive to using reed relays (low cost, no real forward voltage, can easily handle signals to 100 MHz, easy to find components to 100V and above), it looks to my eye a bit clunky with about 20 relays needed for only 2 channels.
I could reduce the count a bit by using an e-pot on some amplifiers but the tolerances look frightening and many seem to be designed for audio and higher frequency signals is an issue for many.
I believe there are GaS options but they seem to be quite pricy where compared to the very affordable reed relays. Generally analog multiplexers have a significant amount of forward voltage that would be a problem in getting the reading correct. VGAs could help some but that would still leave a lot of reed relays.
My question is if there is another good solution that I am overlooking?
Thanks
- Different Signal Voltage (compensated step attenuator)
- AD/DC coupling
- Op Amp Gain Control
- Bias Control
The research I have done to date has pointed me to using reed relays to control where the signal goes given the settings input. While there is quite a bit of positive to using reed relays (low cost, no real forward voltage, can easily handle signals to 100 MHz, easy to find components to 100V and above), it looks to my eye a bit clunky with about 20 relays needed for only 2 channels.
I could reduce the count a bit by using an e-pot on some amplifiers but the tolerances look frightening and many seem to be designed for audio and higher frequency signals is an issue for many.
I believe there are GaS options but they seem to be quite pricy where compared to the very affordable reed relays. Generally analog multiplexers have a significant amount of forward voltage that would be a problem in getting the reading correct. VGAs could help some but that would still leave a lot of reed relays.
My question is if there is another good solution that I am overlooking?
Thanks