Patent ID: 11959962
Assignee: QUALCOMM INCORPORATED
Field: Measurement (Instruments)
Classification: CPC G  H | IPC G

Claim 24:
25. The method of claim 20, wherein detecting the resistance comprises:
closing a first switch, coupled between a first current source and the pin, at a beginning of a first period to provide a first current from the first current source to the pin;
opening the first switch at an end of the first period;
sampling a first voltage of the pin during the first period and holding the sampled first voltage at the end of the first period, with a first sample-and-hold circuit;
closing a second switch, coupled between a second current source and the pin, at a beginning of a second period to provide a second current from the second current source to the pin;
opening the second switch at an end of the second period;
sampling a second voltage of the pin during the second period and holding the sampled second voltage at the end of the second period, with a second sample-and-hold circuit;
quantizing a voltage difference between the held first voltage and the held second voltage with an analog-to-digital converter (ADC); and
determining the resistance of a resistive element in the lumped parameter model based on a value of the first current, a value of the second current, and the quantized voltage difference.