#846 Use a 567 instead of a 555

Episode 846
This only requires one resistor and one capacitor for a clock circuit. I also try the jitter measurement mode on the Rigol MSO5000. Is the 567 12 better than the 555

[Kirillissimus]

If you just need to generate some squarewave then there is an even simpler way: LM3909 LED blinker IC. No need for the extra resistor, just add a capacitor, hook up the power, add a bunch of wires and it just works.

Although in the modern era when even a toilet brush can not hit the market without a WiFi or Bluetooth connection, an iPhone and Android app, a few blinking LEDs and a buzzer in the handle and a contactless charger in the base station to constantly put some juice in the batteries that would power all the necessary luxuries, I would probably just use an ATtiny MCU and programmed everything including the frequency in. The solution would not require any external components at all to just do its job and it would allow for external digital control that will no doubt be required in the future.

[vincei]

National Semiconductor wrote some of the most excellent datasheets and application notes. I regret leaving all mine behind when I moved from the UK to the US in the 90's. I was reminded of this when I clicked on the LM567 Ti datasheet on Digikey and it pulled up a copy of the datasheet written by National Semiconductor. RIP.

[argcargv]

Cool chip. Note you can get a 555 to generate a clock with a single resistor and a capacitor by placing the resistor between the output and the trigger+threshold pins. This trick works better with the cmos version which has rail to rail output. I am not sure what that hack does to the jitter and stability. The bipolar version probably has some temperature dependence in the output rails which would probably degrade the performance.

[PeetHobby]

Only the 567 cost much more(three times or so), the low cost is why we use mostly the 555 and not timer/clock ICs. And they are not as widely available as the 555.

[ruhnet]

Wow I always just thought it was only a DTMF decoder chip. Very cool other stuff it does, too!

[suncrafterspielt]

would be great some internal explanation and the differences to the 555

[davidharms]

Great video! Thanks for sharing the knowledge! I didn’t know about this ic.

[gyrgrls]

I loved the 3909 before they vanished into obsolescence.

[blackarrow]

Thank you! Can you also do an eye diagram with that scope?

[frankowalker]

What's the jitter level at >1.2 seconds ? I'm looking for a reliable timer circuit.

[braveheart]

IS IT NORMAL FOR THE OSC FREQUENCY TO CHANGE WITH SMALL POWER SUPPLY VOLTAGE CHANGES.

[td]

I have been looking at how to create a 60Hz sine wave. I know you are creating a square wave, but can the 567 be configured to go that slowly, reliably and with decent precision?

[chupathingy]

This thing would be great for a 440hz tone generator. Thanks for the idea!