hexoscillator
I stumbled across this clock generator, and it is new to me.
I'd like to calculate its frequency (actually min and max, since there is a trimmer), but I don't know how to do, since similar oscillator looks simpler than this.
I tried to simulate this schematic, but it didn't work.
Found it. MPC is Monitor Products Company, bought out by MMD Components (MMD Monitor/Quartztek Frequency Control Products) in 2002.
970T Datasheet Low-Cost, Full-Size TTL-compatible Clock Oscillator
Why don't you just use the circuit design recommended by the buzzer manufacturer in their data sheet. I.E. this circuit:
This uses a simple CD4049 chip, two resistors and a small capacitor. This curcuit gives you the gain you need to make the oscillation work.
Best Answer
This design might fail on some simulators if the internal ESD diodes are not included.
The gain margin frequency have not have enough gain at the limited slew rate where the frequency is unity gain to produce an output. If AC noise at Vdd/2 the 2nd stage is less than the offset voltage from mismatched FETs , it may not oscillate and just stay at 2.5V
I could simulate failure without diodes and success with internal diodes here.
As for frequency, guess what RC=T is when the ramp goes from diode drop outside rail to Vd/2. Hint f=1/2T with some tolerance for thresholds +/-25%