US Patent No. 9,689,724


Patent No. 9,689,724
Issue Date June 27, 2017
Title Resonant Signal Sensing Circuit Having A Low Power Mode
Inventorship Marty Pflum, Austin, TX (US)
Assignee Silicon Laboratories Inc., Austin, TX (US)

Claim of US Patent No. 9,689,724

10. A metering circuit comprising:
a sensor circuit connected to an input that is coupled to the input to receive the resonant signal corresponding to the usage
of the resource from an external circuit;

a timer circuit to generate a timer signal at selected intervals;
a microcontroller unit configured to remain in a low power mode and to transition to a higher power mode in response to a
wakeup signal; and

a controller coupled to the timer circuit and the sensor circuit, the controller having a first power mode and a second power
mode, the first power mode having a lower power consumption than the second power mode, the controller configured to enter
the second power mode and enable the sensor circuit to capture measurements of the resonant signal in response to receiving
the timer signal, the controller configured to selectively provide the wakeup signal to the microcontroller unit based on
the measurements of the resonant signal.