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.