Low-power circuit and method for providing rapid frequency lock in a wireless communications device

A low-power circuit for rapidly locking the frequency of a carrier signal, comprising:

• a programmable phase-lock loop (PLL) chip coupled to a voltage-controlled oscillator (VCO) to form a PLL circuit, an output of said VCO circuit providing said carrier signal;
• and
• a sample-and-hold circuit connected between said PLL chip and said VCO such that a feedback loop of said PLL circuit is closed when said sample-and-hold circuit is in a SAMPLE state, and such that said feedback loop is open when said sample-and-hold circuit is in a HOLD state, said sample-and-hold circuit thereby allowing said carrier signal to be held at a fixed frequency without waiting for said PLL circuit to reach a phase-locked state.

A battery-powered remote telemeter, comprising:

• a transceiver circuit comprising a phase-lock loop (PLL) circuit, said PLL circuit having a sample-and-hold circuit connected in a feedback loop thereof, said sample-and-hold circuit connected such that said feedback loop is closed when said sample-and-hold circuit is in a SAMPLE state, and such that said feedback loop is open when said sample-and-hold circuit is in a HOLD state;
• and
• a battery-powered microcontroller coupled to said transceiver circuit, said microcontroller programmed to send and receive data packets via said transceiver circuit using a two-way TDMA data transfer protocol.