US 12,335,887 B2
Calibration of a low frequency oscillator using a high frequency oscillator as a reference clock
Tuomas Hanninen, Helsinki (FI); and Sebastien Cerdan, Montigny le Bretonneux (FR)
Assigned to Silicon Laboratories Inc., Austin, TX (US)
Filed by Silicon Laboratories Inc., Austin, TX (US)
Filed on Sep. 8, 2022, as Appl. No. 17/940,483.
Prior Publication US 2024/0098668 A1, Mar. 21, 2024
Int. Cl. H04W 56/00 (2009.01)
CPC H04W 56/004 (2013.01) 20 Claims
OG exemplary drawing
 
1. A method for operating a wireless communications device having a low energy mode of operation and a second mode of operation, the method comprising:
providing a first clock signal and a second clock signal in the second mode of operation, the first clock signal having a first frequency within a first frequency offset range, the second clock signal having a second frequency within a second frequency offset range, the first frequency being lower than the second frequency, and the first frequency offset range being greater than the second frequency offset range;
generating a calibrated version of the first clock signal in the second mode of operation using a measurement of the first clock signal measured using a timer controlled by the second clock signal; and
using the calibrated version of the first clock signal in the low energy mode of operation while the second clock signal is disabled.