Alternative to LTC6904 Programmable Oscsillator Chip

[Visitor]

THE LTC6904 is an I2C-programmable oscillator that operstes over a range of 1kHz to 68MHz. I'm using one of these over a tiny portion of that range (audio frequencies) to drive a speaker as an alternative to a piezo beeper – the circuit gives me volume control and adjustable frequency.

Does anyone know of a similar I2C programmable oscillator operating down to 1kHz, with good resolution from 1kHz – 5kHz? Preferably available for JLC assembly? Other programmable clock generator chips don't go down to this range.

Thanks in advance for any possible substitutes. I do want a square wave output, which I run through an integrator stage, which provides pretty good replication to the sound of a piezo beeper. A pure sin wave doesn't sound as good.

 

[JimB]

Have a look at the AD9850 DDS, it can go down to 0Hz and the resolution is 0.0291Hz when using a 125Mhz clock.

JimB

 

[Visitor]

That is an excellent suggestion and I'm not sure why I didn't consider it for the first version of this circuit.

I used the AD9850 years ago to duplicate the "Live or Memorex" commercial with Ella Fitzgerald to shatter a wine glass with sound. I provided the electronics to help a friend build an exhibit for the Tacoma (Washington, USA) Museum of Glass. Turns out it's difficult to do anymore, as wine glasses have been engineered to reduce breakage. It takes quite expensive wine glasses (>$10/stem) to do this with any reasonable acoustic power. If I recall correctly, we used Peavey 44 drivers for public address horns – the power needed to shatter a wine glass was approximately the power needed to blow out the Peavey driver! This turned into a costly project!

**broken link removed**