# US 2014/0153732 A1 · Signal processing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0153732 A1 - Document ID: US20140153732A1 - Status: Published application - Kind: A1 - Application number: 14/119,512 - Filed: 2012-05-15 - Published: 2014-06-05 - Earliest claimed: 2011-05-27 - Assignees: ST-Ericsson SA - Inventors: Christian Fraisse; Angelo Nagari - Web page: https://patentgrep.com/patent/US20140153732A1 ## CPC - H03F 3/217: Class D power amplifiers; Switching amplifiers - H03K 7/08: Duration or width modulation {; Duty cycle modulation} - H03F: AMPLIFIERS - H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M) ## Abstract The electronic device and a corresponding signal processing method disclosed herein reduces electromagnetic noise. To that end, the electronic device includes a delay line, an oscillator, and a modulator. The delay line generates a spread spectrum clock signal from an input clock signal, where a timing jitter and a period of jitter of the spread spectrum clock signal are controlled at each period of the spread spectrum clock signal based on a digital code. The oscillator uses the spread spectrum clock signal to generate a processing signal. The modulator modulates the processing signal as a function of an audio signal. ## Claims ### Claim at position 1 1-13. (canceled) ### Claim 14 A signal processing electronic device configured to reduce electromagnetic noise, the electronic device comprising: a delay line configured to generate a spread spectrum clock signal from an input clock signal, a timing jitter and a period jitter of the spread spectrum clock signal being controlled at each period of the spread spectrum clock signal based on a digital code; an oscillator configured to use the spread spectrum clock signal to generate a processing signal; and a modulator configured to modulate the processing signal as a function of an audio signal. ### Claim 15 (depends on 14) The electronic device according to claim 14, wherein the timing jitter and the period jitter are controlled to follow predetermined distribution curves. ### Claim 16 (depends on 15) The electronic device according to claim 15, wherein the predetermined distribution curves comprise sine waves. ### Claim 17 (depends on 14) The electronic device according to claim 14, wherein the delay line comprises a set of delay blocks in cascade, each delay block comprising a resistor-capacitor (RC) circuit, and each delay block being controlled based on one bit of the digital code. ### Claim 18 (depends on 17) The electronic device according to claim 17, wherein a unitary delay quantization is defined by a first capacitance of a first RC circuit, with a capacitance of each remaining RC circuit being a multiple of the first capacitance. ### Claim 19 (depends on 14) The electronic device according to claim 14, further comprising, a digital code generator configured to generate, at each period, the digital code, the digital code generator comprising: a counter configured to generate a counter value from the input clock signal; a decoder configured to receive the counter value and to set a binary variable value based on the counter value; and a sequencer configured to receive the binary variable value and to generate the digital code based on the binary variable value. ### Claim 20 (depends on 19) The electronic device according to claim 19, wherein the counter value comprises M bits, and wherein the counter comprises M outputs for generating the M bits of the counter value, M being an integer. ### Claim 21 (depends on 19) The electronic device according to claim 19, wherein the counter comprises a first set of latches connected in cascade, an output of each latch providing a bit of the counter value. ### Claim 22 (depends on 19) The electronic device according to claim 19, wherein the sequencer comprises a second set of latches connected in cascade, an output of each latch providing a bit of the digital code. ### Claim 23 A method of processing a signal to reduce electromagnetic noise, the method comprising: generating a spread spectrum clock signal from an input clock signal, a timing jitter and a period jitter of the spread spectrum clock signal being controlled at each period of the spread spectrum clock signal based on a digital code; using the spread spectrum clock signal to generate a processing signal; and modulating the processing signal as a function of an audio signal. ### Claim 24 (depends on 23) The method according to claim 23, further comprising controlling the timing jitter and the period jitter to follow predetermined distribution curves. ### Claim 25 (depends on 10) The method according to claim 10, wherein the predetermined distribution curves comprise sine waves. ### Claim 26 (depends on 23) The method according to claim 23, further comprising generating, at each period, a digital code by: generating a counter value from the input clock signal; setting a binary variable value based on the counter value; and generating the digital code based on the binary variable value. ### Claim 27 A computer program product stored in a non-transitory computer readable medium for controlling a data-processing unit, the computer program product comprising software instructions which, when run on the data-processing unit cause the data processing unit to: generate a spread spectrum clock signal from an input clock signal, a timing jitter and a period jitter of the spread spectrum clock signal being controlled at each period of the spread spectrum clock signal based on a digital code; use the spread spectrum clock signal to generate a processing signal; and modulate the processing signal as a function of an audio signal.