A crystal oscillator-based module, which includes a crystal resonator receiving a conditioned signal from a first bus and passing a resonator signal to a sustaining stage amplifier. A synchronization range expansion circuit is connected between a gain control network and the resonator. A tri-state buffer has a main input connected to receive the resonator signal through a buffer. The output of the tri-state buffer is connected to a second bus, through a matching network if necessary. A synchronous clock system can be formed by connecting these modules alternately to the two busses. The tri-state buffer also has a control input, which may be connected to a delay circuit between Vcc and ground, so as to allow hot swapping and for other benefits.