摘要:
A starter circuit (128) for an electronic device includes a rectifier circuit (212) having an input coupled to an antenna (222); a Schmidt trigger (214) coupled to the rectifier circuit; a pulse timer circuit (216) coupled to receive pulses from the Schmidt trigger (214) and configured to measure pulse characteristics to determine whether the pulses are part of a valid startup sequence and to generate a reset signal if the pulses are not part of a valid startup sequence; and a counter (218) having first and second inputs coupled to outputs of the pulse timer circuit, the counter (218) configured to output a signal to initiate power-on of a component of the electronic device a when its count value reaches a predetermined value.
摘要:
Systems and methods are provided in which an offset phase-locked loop (PLL) system can be configured as part of a radio frequency transmitter. The PLL can include a phase detection circuit including a first input configured to receive an information signal and a second input configured to receive a feedback signal; a charge pump including an input coupled to the phase detection circuit and an output; a filter including an input coupled to the output of the charge pump; a voltage-controlled oscillator coupled to the charge pump and including an LC tank circuit comprising an inductive element and a capacitive element, wherein the inductive element of the LC tank circuit comprises the antenna; and a feedback path.
摘要:
Systems and methods are provided in which a voltage-controlled oscillator for a radio transmitter includes a LC tank circuit, and a muting circuit. The LC tank circuit includes an inductive element and a capacitive element; wherein the inductive element of the LC tank circuit includes the antenna of the transmitter. The muting circuit can include a variable resistor connected in parallel with the LC tank circuit.