21.20(a) is generally known as the Pierce crystal. The ensuing circuit frequency of oscillations is ready because of the series resonant frequency from the crystal. Variations in supply voltage, transistor parameters, etc. have no impact on the circuit functioning frequency and that is held stabilized because of the crystal. The https://angeloswybb.look4blog.com/73134140/how-much-you-need-to-expect-you-ll-pay-for-a-good-timing-components-for-consumer-electronics