Timeline for Source of noise
Current License: CC BY-SA 4.0
14 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Aug 11, 2022 at 15:19 | vote | accept | AlveyFrost | ||
| Jul 15, 2022 at 20:35 | comment | added | PStechPaul | You can get 5 pieces of 100x100 mm PC boards made and delivered for about $20 from PCBWAY or jlcpcb.com, but you need to wait about 2 weeks. For a critical design like this, I would advise making a proper board, perhaps with extra pads and test points for additional components and breadboarding. A perfboard like you are using is OK for simple circuits, but it's difficult to get working properly unless you are very skilled at making connections and placing components, | |
| Jul 15, 2022 at 17:19 | history | edited | ocrdu | CC BY-SA 4.0 |
added 2 characters in body; edited title
|
| Jul 15, 2022 at 14:51 | comment | added | AlveyFrost | Thank you for the suggestions, I will use try using the decoupling capacitors, use the ground plane, and bias the comparator in case it still does not work out. | |
| Jul 15, 2022 at 14:08 | comment | added | SteveSh | Two things to add to the good advice Andy aka gave in his answer. You could also try adding a bias to one of the comparator's inputs, so that in the absence of the 4 MHz signal the comparator is biased well away from its trip point. Also, look for a slower part. The comparator you chose is way faster than it needs to be for your application, which can lead to all sorts of unexpected problems. | |
| Jul 15, 2022 at 13:27 | answer | added | Lundin | timeline score: 2 | |
| Jul 15, 2022 at 13:16 | comment | added | rdtsc | As a total hack, could try placing a 100pF ceramic capacitor across the AC+ and AC-. This might clean up the signal somewhat, but it's going to make the signal generator work harder (more capacitive load) and possibly delay the signal slightly. At this point, I'd be considering designing a PCB with a ground plane; even a two-layer board would be better than fly-wiring. See OSHPark, JLCPCB, etc. | |
| Jul 15, 2022 at 12:36 | comment | added | AlveyFrost | The ground plane and the decoupling caps are not being used. Yes, the ICs are mounted on SMD to DIP adapters. Would you say a decoupling capacitor between 3.3V and GND pin of the uC is sufficient or should they be connected between Vcc and GND of all the ICb eing used? | |
| Jul 15, 2022 at 12:30 | answer | added | Andy aka | timeline score: 4 | |
| Jul 15, 2022 at 12:27 | comment | added | Mattman944 | So, inbetween sine wave bursts the signal is zero? If yes, then you need to bias the inputs slightly, or add hysteresis. | |
| Jul 15, 2022 at 12:17 | comment | added | bobflux | The perfboard has a ground plane... are you using it? Is the chip on a SMD to DIP adapter? How many decoupling caps? | |
| Jul 15, 2022 at 12:03 | history | edited | toolic | CC BY-SA 4.0 |
added 9 characters in body
|
| S Jul 15, 2022 at 11:59 | review | First questions | |||
| Jul 15, 2022 at 12:44 | |||||
| S Jul 15, 2022 at 11:59 | history | asked | AlveyFrost | CC BY-SA 4.0 |