US 11,817,868 B2
Apparatus for digital frequency synthesizer with sigma-delta modulator and associated methods
John M. Khoury, Austin, TX (US)
Assigned to Silicon Laboratories Inc., Austin, TX (US)
Filed by Silicon Laboratories Inc., Austin, TX (US)
Filed on Jun. 30, 2022, as Appl. No. 17/855,525.
Application 17/855,525 is a continuation of application No. 16/221,436, filed on Dec. 14, 2018.
Prior Publication US 2022/0337254 A1, Oct. 20, 2022
Int. Cl. H03L 7/099 (2006.01); H03L 7/085 (2006.01); G06F 1/02 (2006.01); H03B 5/12 (2006.01); H03L 7/14 (2006.01); H03L 7/189 (2006.01); H03L 7/197 (2006.01)
CPC H03L 7/0991 (2013.01) [G06F 1/022 (2013.01); H03B 5/1206 (2013.01); H03B 5/1212 (2013.01); H03B 5/1218 (2013.01); H03B 5/1228 (2013.01); H03B 5/1243 (2013.01); H03B 5/1265 (2013.01); H03L 7/085 (2013.01); H03L 7/099 (2013.01); H03L 7/0992 (2013.01); H03L 7/148 (2013.01); H03L 7/189 (2013.01); H03L 7/1974 (2013.01)] 22 Claims
OG exemplary drawing
 
1. An apparatus comprising: a sigma-delta modulator (SDM) having three modes of operation; wherein an integer (N) is provided as a first input to the SDM; wherein an output signal of the SDM toggles between two values derived from the integer (N); and wherein a derivation of the two values depends on whether the SDM is operating in a first mode, a second mode, or a third mode of the three modes of operation.