US Patent 7148787 Remote keyless entry circuit having transient pulse suppression

A remote keyless entry (RKE) circuit (100) and method reduces the amount of current draw by duty cycling the RKE circuit (100) to ensure that a microcontroller (104) in the RKE circuit (100) is awakened only when needed to evaluate RF data. A total operating period for the RKE circuit (100) includes a transient period, a data monitoring period, and a sleep period. The RKE circuit (100) includes a pulse blocking circuit (109) that prevents a receiver stabilization pulse from waking up the microcontroller (104). If no data is received during the data monitoring period, the microcontroller (104) remains in a sleep mode for the remainder of the operating period.