Frequency Response Analyser Progress

RE: Frequency Response Analyser Progress

Jan Cumps — Sun, 07 Jun 2020 18:02:53 GMT

In the final schematic you've replaced the 2 series diodes by BAV99 single packet.

Did you have a specific reason for selecting that device/package?

RE: Frequency Response Analyser Progress

dubbie — Mon, 25 May 2020 09:47:58 GMT

Very nice. Not my cup of tea, but still, nice. Maybe put some wheels on and make it into a mobile robot, then it would be really nice!

Dubbie

RE: Frequency Response Analyser Progress

shabaz — Mon, 25 May 2020 00:45:19 GMT

I was searching my files for some document, and came across old lab coursework I'd written back in college.. I'd totally forgotten, this is how we measured networks during practical lessons back then.. just with a sig-gen and a 'scope : ).

[View:/resized-image/__size/620x465/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-37a0febe-acbd-4d3b-8c39-6844cc42e14f/6102.contentimage_5F00_207036.jpg:620:465]

[View:/resized-image/__size/620x827/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-37a0febe-acbd-4d3b-8c39-6844cc42e14f/0654.contentimage_5F00_207037.jpg:620:827]

RE: Frequency Response Analyser Progress

shabaz — Sun, 24 May 2020 22:45:20 GMT

Hi Michael,

Really nice project! I've been thinking of making an amplifier for a DDS too, but it never left paper. I was going to use THS3091 but your discrete PA output is much more interesting. I will ditch my design hehe, since yours is way ahead.

My offset adjustment was just 10-bit (AD5293 digipot, driving an op-amp similar as you have it (except mine was wired non-inverting), driving the inverting input into the THS3091, but since 10-bit is not very granular I intended to also have a trimmer resistor on the inverting input of the digipot's op-amp for tweaking so that I wouldn't have some non-zero offset I couldn't remove in 10 bits.

I've been playing with CMSIS DSP recently too, it's impressive how these features are available across all (or maybe nearly all) Cortex-M processors.

Also, it's really cool how you're able to switch the measurements across both outputs. Are they going to ADCs in the microcontroller, or some separate ADC board?

Anyway, it's an awesome project, looking forward to seeing it all come to shape!

RE: Frequency Response Analyser Progress

DAB — Sun, 24 May 2020 18:06:45 GMT

Interesting project.

DAB