Using a triangular waveform to synchronize the operation of an electronic circuit
View Patent ↗An electronic circuit exhibiting synchronization with an external synchronization signal, the electronic circuit comprising: an input connection arranged to receive a synchronization input signal; a triangular waveform oscillator operatively associated with the synchronization signal input connection and responsive to a condition of the received synchronization input signal to initiate a triangular waveform; and a pulse train generator operatively associated with the triangular waveform oscillator, the pulse train generator arranged to generate a plurality of pulse trains having a fixed non-zero phase relationship between them and a frequency responsive to the condition of the synchronization input signal.
1. A method of synchronizing the operation of at least one electronic circuit, the method comprising:
generating a triangular waveform signal responsive to a synchronization signal, said triangular waveform signal exhibiting a fundamental first frequency, said synchronization signal exhibiting a second frequency;
generating a plurality of pulse trains having a fixed non-zero phase relationship between them, wherein said pulse trains exhibit one of said first frequency and said second frequency; and
modulating a received control signal with said generated plurality of pulse trains to generate a plurality of modulated pulse trains exhibiting said fixed non-zero phase relationship and a synchronization with the synchronization signal.
2. The method of claim 1 , wherein the received control signal comprises a pulse width modulation (PWM) signal.
3. The method of claim 1 , wherein the at least one electronic circuit is a cold cathode fluorescent lamp controller.
4. The method of claim 1 , wherein said plurality of pulse trains comprise two pulse trains and wherein said fixed phase relationship is 180° out of phase.
5. The method of claim 1 , wherein the synchronization signal is a function of a modulated pulse train of another at least one electronic circuit.
6. The method of claim 1 , wherein the synchronization signal is a video scan synchronization signal.
7. The method of claim 1 , wherein said generating a triangular waveform comprises alternatively charging and discharging a capacitor with at least one current source.
8. The method of claim 1 , wherein said generating a triangular waveform comprises alternatively charging a capacitor with a first current source and discharging the capacitor with a second current source.
9. The method of claim 1 , wherein said first frequency is less than said second frequency, and wherein said generated plurality of modulated pulse trains exhibit said second frequency.
10. The method of claim 1 , wherein said first frequency is less than said second frequency, said generated plurality of modulated pulse trains exhibit said second frequency, said plurality of pulse trains comprise two pulse trains and said fixed phase relationship is 180° out of phase.
11. An electronic circuit exhibiting synchronization comprising:
an input connection arranged to receive a synchronization input signal;
a triangular waveform oscillator operatively associated with said synchronization signal input connection and responsive to a condition of said received synchronization input signal to initiate a triangular waveform;
a pulse train generator operatively associated with said triangular waveform oscillator, said pulse train generator arranged to generate a plurality of pulse trains having a fixed non-zero phase relationship between them and a frequency substantially equivalent to one of the free running frequency of said triangular waveform oscillator and the frequency of the received synchronization input signal; and
a signal modulator operatively associated with said pulse train generator and arranged to generate a plurality of modulated pulse trains exhibiting said fixed non-zero phase relationship and said frequency responsive to said condition of said synchronization input signal.
12. An electronic circuit according to claim 11 , wherein said signal modulator is arranged to receive a pulse width modulated signal and modulate each of said plurality of pulse trains with said received pulse width modulated signal.
13. An electronic circuit according to claim 11 , wherein said received synchronization input signal is a function of a modulated pulse train of another electronic circuit according to claim 11 .
14. An electronic circuit according to claim 11 , wherein the electronic circuit is a cold cathode fluorescent lamp controller.
15. An electronic circuit according to claim 11 , wherein said plurality of pulse trains comprise two pulse trains and wherein said fixed phase relationship is 180° out of phase.
16. An electronic circuit according to claim 11 , wherein the received synchronization input signal is a video scan synchronization signal.
17. An electronic circuit according to claim 11 , wherein said triangular waveform oscillator comprises at least one current source arranged to alternatively charge and discharge a capacitor.
18. An electronic circuit according to claim 11 , wherein said triangular waveform oscillator comprises a first current source and a second current source arranged to alternatively charge and discharge a capacitor.
19. An electronic circuit according to claim 11 , wherein said frequency of said plurality of pulse trains is substantially equivalent to the frequency of the received synchronization input signal.