Transmitting apparatus of digital signals on a supply line of electronic devices and corresponding method

Abstract

A power converter having a noise component and a modulator configured to vary a frequency of the noise component of the power converter on the basis of a digital signal to be transmitted.

The invention claimed is: 
     
       1. A transmitting apparatus of digital signals on a line in which there is a supply signal, comprising:
 a direct-voltage switching converter; 
 means for varying the switching frequency of said converter on the basis of a digital signal to be transmitted, said converter being suitable for generating an alternating current signal associated with the supply signal during the switching periods; and 
 means for receiving said alternating current signal and suitable for processing the latter to obtain said digital signal. 
 
     
     
       2. The apparatus according to  claim 1 , wherein said means for receiving comprises means for the alternating coupling of said alternating current signal, a peak detector, a signal sampler, a low-pass filter and a frequency discriminator suitable for decoding the transmitted digital signal. 
     
     
       3. The apparatus according to  claim 2 , wherein said means for varying the switching frequency of the converter uses a first switching frequency for transmitting a “1” and a second switching frequency for transmitting a “0”. 
     
     
       4. The apparatus according to  claim 3 , wherein said first and second switching frequency are different from a nominal frequency of the converter and said peak detector has an output frequency that is proportional to the difference between said nominal frequency and said first frequency or to the difference between said nominal frequency and said second frequency. 
     
     
       5. The apparatus according to  claim 1 , wherein said means for varying the switching frequency of the converter uses a first switching frequency for transmitting a “1” and a second switching frequency for transmitting a “0”. 
     
     
       6. The apparatus according to  claim 1  wherein said transmitting apparatus is a PFC of an AC-DC converter, said PFC comprising said DC-DC switching converter including a power transistor and a control circuit of said power transistor, said means adapted to vary the switching frequency of said converter on the base basis of said digital signal being associated with the control circuit of said power transistor. 
     
     
       7. A method for transmitting digital signals on a line wherein there is a supply signal of electronic devices, said method comprising varying a switching frequency of a direct-voltage switching converter on the basis of a digital signal to be transmitted, generating an alternating current signal associated with the supply signal during the switching periods, receiving said alternating current signal and processing thereof to obtain said digital signal. 
     
     
       8. A system, comprising:
 a line configured to provide a power supply signal for a plurality of electronic devices; and 
 a transmitting apparatus configured to transmit digital signals on said line wherein said transmitting apparatus comprises:
 a switching converter; 
 means for varying the switching frequency of said converter on the basis of a digital signal to be transmitted, said converter being suitable for generating an alternating current signal associated with the power supply signal during the switching periods; and 
 means for receiving said alternating current signal and for processing the latter to obtain said digital signal. 
 
 
     
     
       9. The system according to  claim 8  wherein said means for receiving is coupled with a converter of another of the plurality of electronic devices. 
     
     
       10. The system according to  claim 8  wherein said means for receiving comprises means for the alternating coupling of said alternating current signal, a peak detector, a signal sampler, a low-pass filter and a frequency discriminator suitable for decoding the transmitted digital signal. 
     
     
       11. The system according to  claim 10  wherein said means for varying the switching frequency of the converter is configured to generate a first switching frequency for transmitting a “1” and a second switching frequency for transmitting a “0”. 
     
     
       12. The system according to  claim 11 , wherein said first and second switching frequency are different from a nominal frequency of the converter and said peak detector has an output frequency that is proportional to the difference between said nominal frequency and said first frequency or to the difference between said nominal frequency and said second frequency. 
     
     
       13. The system according to  claim 8 , further comprising an AC-DC converter including a PFC, said PFC comprising said switching converter including a power transistor and a control circuit of said power transistor, said means adapted to vary the switching frequency of said converter on the base basis of said digital signal being associated with the control circuit of said power transistor. 
     
     
       14. A transceiver, comprising:
 a switching power converter having a variable switching frequency; 
 a modulator configured to vary the switching frequency of the switching power converter based on a digital signal; and 
 a receiver configured to detect the switching frequency of the power converter and output the digital signal based on the detected switching frequency. 
 
     
     
       15. The transceiver of  claim 14  wherein the receiver comprises:
 a peak detector; 
 a signal sampler; 
 a low-pass filter; and 
 a frequency discriminator. 
 
     
     
       16. The transceiver of  claim 14  wherein the modulator is configured to cause the power converter to use a first switching frequency to transmit a one and to cause the power converter to use a second switching frequency to transmit a zero. 
     
     
       17. The transceiver of  claim 16  wherein the power converter has a nominal switching frequency different from the first and second switching frequencies. 
     
     
       18. The transceiver of  claim 14  wherein the receiver comprises a second switching power converter. 
     
     
       19. A system, comprising:
 a power supply line; 
 a transmitter having:
 a first power converter having a variable switching frequency and coupled to the power supply line; and 
 a modulator configured to vary the switching frequency of the first power converter based on a digital signal; and 
 
 a demodulator coupled to the power supply line and configured to detect the switching frequency of the first power converter. 
 
     
     
       20. The system of  claim 19 , further comprising:
 an AC-DC converter coupled to the power supply line, wherein the first power converter comprises a DC-DC converter having a transistor and a feedback loop and the modulator is coupled to the feedback loop. 
 
     
     
       21. A method of transmitting a digital signal between a plurality of devices coupled to a power supply line, the method comprising:
 modulating a feedback signal of a power converter of one of the plurality of devices based on the digital signal; 
 detecting the modulation of the feedback signal; and 
 reproducing the digital signal based on the detected modulation of the feedback signal. 
 
     
     
       22. The method of  claim 21  wherein modulating the feedback signal comprises:
 modulating a duty cycle of the power converter. 
 
     
     
       23. A system, comprising:
 a DC power line; 
 an AC-DC converter having an output coupled to the DC power line; 
 a transmitter having:
 a DC-DC power converter having a feedback loop and coupled to the DC power line; and 
 a modulator configured to modulate a signal in the feedback loop of the DC-DC power converter based on a digital signal; and 
 
 a demodulator coupled to the DC power line and configured to detect the modulated signal. 
 
     
     
       24. The system of  claim 23  wherein the DC-DC power converter comprises a transistor and an inductor and the feedback loop comprises an error amplifier, wherein the modulator is configured to modulate a duty cycle of the DC-DC power converter. 
     
     
       25. A receiver, comprising:
 an input configured to couple to a direct-current (DC) bus line; and   a demodulator coupled to the input and configured to extract digital signals transmitted on the DC bus line based on frequencies associated with a bounce signal from a switching converter on the DC bus line.   
     
     
       26. The receiver of claim 25 wherein the demodulator comprises:
 a peak detector;   a signal sampler;   a low-pass filter; and   a frequency discriminator.   
     
     
       27. The receiver of claim 25 wherein the demodulator is configured to determine switching frequencies based on received bounce signals and to determine bits of a received digital signal based on the determined switching frequencies. 
     
     
       28. The receiver of claim 27 wherein a first switching frequency represents a bit having a value of zero and a second switching frequency represents a bit having a value of one. 
     
     
       29. The receiver of claim 28 wherein the demodulator is configured to determine bits of the digital signal based on the determined switching frequencies and a nominal switching frequency. 
     
     
       30. A transmitter, comprising:
 an output terminal to output a control signal to a switching converter; and   a controller coupled to the output terminal and configured to generate the control signal to vary frequencies associated with a bounce signal of the switching converter on the basis of a digital signal to be transmitted by the switching converter on a direct current (DC) bus line.   
     
     
       31. The transmitter according to claim 30 wherein said controller is configured to generate the control signal to cause the switching converter to use a first switching frequency to transmit a “1” and a second switching frequency to transmit a “0”. 
     
     
       32. The transmitter according to claim 31, wherein said first and second switching frequencies are different from a nominal frequency of the switching converter. 
     
     
       33. The transmitter according to claim 30 wherein the controller is configured to generate the control signal to control a power transistor of the switching converter. 
     
     
       34. The transmitter of claim 30, further comprising the switching converter, wherein the switching converter is a DC to DC converter. 
     
     
       35. A transmitter, comprising:
 a Direct Current (DC) to DC power converter having a feedback loop and configured to couple to a DC power line; and   a modulator coupled to the power converter and configured to modulate a signal in the feedback loop of the power converter based on a digital signal to be transmitted on the DC power line.   
     
     
       36. The transmitter of claim 35 wherein the power converter comprises a transistor and an inductor and the feedback loop comprises an error amplifier, wherein the modulator is configured to modulate a duty cycle of the power converter.