US 12,449,455 B2
Circuit for determining the frequency of a signal
Wei Wang, Munich (DE); Michael Augustin, Villach (AT); Jürgen Schäfer, Oberhaching (DE); Dietmar König, Munich (DE); Josef Niederl, Klagenfurt (AT); and Shane O'Neill, Cork (IE)
Assigned to Infineon Technologies AG, Neubiberg (DE)
Filed by Infineon Technologies AG, Neubiberg (DE)
Filed on Oct. 25, 2023, as Appl. No. 18/493,866.
Claims priority of application No. 10 2022 128 332.1 (DE), filed on Oct. 26, 2022; and application No. 10 2023 121 088.2 (DE), filed on Aug. 8, 2023.
Prior Publication US 2024/0142503 A1, May 2, 2024
Int. Cl. G01R 23/167 (2006.01)
CPC G01R 23/167 (2013.01) 20 Claims
OG exemplary drawing
 
1. A circuit for determining a frequency of a signal, comprising:
an input configured to receive an analog input signal;
an analog to digital converter configured to convert the analog input signal to a digital input signal;
a digital mixer configured to generate a mixing result signal by mixing the digital input signal with a single bit binary signal having a reference frequency;
a low pass filter configured to generate a filtered signal by filtering the mixing result signal;
a measuring circuit configured to measure a period of the filtered signal; and
an output configured to output a value of the frequency of the signal, wherein the frequency of the signal differs from the frequency of the single bit binary signal by a frequency offset determined by an inverse of the measured period.