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</head><body><p>Think that we need to pay attention to the fact that this is a 74HC4046 and not a CD4046. From looking at the data sheet they are different chips with different characteristics.</p><p><br></p><p>Some where and I can't remember where I remember reading something about this for the CD4046 and you should give it a small bias for the frequency or things can get weird.</p><p><br></p><p>Jay S.</p><blockquote><p>On June 20, 2017 at 5:21 PM Tim Ressel <timr@circuitabbey.com> wrote:</p><p>Hi,</p><p>According the TI spec sheet the range for the VCOin pin is 1.1 volts to<br>about 4 volts depending on the supply.</p><p>The Thomas Henry 4046 VCO design (X-4046) ran a current source from an<br>expo converter into pin 11 (R1) and tied the VCOin pin to +V. You might<br>try that.</p><p>--timbo</p><p>On 6/20/2017 1:09 PM, mark verbos wrote:</p><blockquote><p>hi all,</p><p>I’m making a new digital delay using some adaptive Delta type 1 bit techniques. I’d like a clock that can be swept from 250kHz to 3MHz without any glitches.<br>I’m using a 74HC4046 and it is almost right, but it freaks out when the CV gets near zero and jumps down to a lower frequency. Is this normal? What am I doing wrong?<br>I have a 220p cap and a 10k on pin 11 and a 100k on pin 12.</p><p>Thanks for any insights…</p><p>Mark</p><p>_______________________________________________<br>Synth-diy mailing list<br>Synth-diy@synth-diy.org<br><a href="http://synth-diy.org/mailman/listinfo/synth-diy">http://synth-diy.org/mailman/listinfo/synth-diy</a></p></blockquote><p>--<br>--Tim Ressel<br>Circuit Abbey<br>timr@circuitabbey.com</p><p>_______________________________________________<br>Synth-diy mailing list<br>Synth-diy@synth-diy.org<br><a href="http://synth-diy.org/mailman/listinfo/synth-diy">http://synth-diy.org/mailman/listinfo/synth-diy</a></p></blockquote></body></html>