Apparatus, circuit and method for automatic phase-shifting pulse width modulated signal generation
View Patent ↗Systems, circuits and methods for phase-shifting pulse width modulated signal generation are disclosed. In some embodiments, a phase-shifting pulse width modulation circuit is configured to output pulses based on an input pulse width modulated signal. The pulses are staggered relative to one another, and can be received by a light-emitting diode driver for driving a light-emitting diode string at one or more time periods. The phase-shifting pulse width modulation circuit can include a counter-based programmable delay subcircuit consisting of two counter-based programmable delay blocks.
1. A phase-shifting pulse width modulation circuit configured to output pulses based on an input pulse width modulated signal, wherein the pulses are staggered relative to one another, the phase-shifting pulse width modulation circuit comprising a counter-based programmable delay subcircuit consisting of two counter-based programmable delay blocks.
2. The phase-shifting pulse width modulation circuit of claim 1 , wherein the phase-shifting pulse width modulation circuit is implemented in hardware.
3. The phase-shifting pulse width modulation circuit of claim 1 , wherein the pulses are non-overlapping.
4. A phase-shifting pulse width modulation circuit configured to output pulses based on an input pulse width modulated signal, wherein the pulses are staggered relative to one another for powering a plurality of light emitting diode arrays during one or more time periods, the phase-shifting pulse width modulation circuit comprising a counter-based programmable delay subcircuit having a fixed number of counter-based programmable delay blocks, the counter-based programmable delay subcircuit configured to output information for generation of the pulses, and the plurality of light emitting diode arrays is a number greater than the fixed number of counter-based programmable delay blocks.
5. The phase-shifting pulse width modulation circuit of claim 4 , wherein the fixed number of counter-based programmable delay blocks is two.
6. The phase-shifting pulse width modulation circuit of claim 4 , wherein the pulses are non-overlapping.
7. The phase-shifting pulse width modulation circuit of claim 4 , further comprising:
a period measurement block configured to measure a period of an input signal to the phase-shifting pulse width modulation circuit;
an edge distributor block configured to:
receive the input signal; and
output information indicative of a detection of a rising edge of the input signal and information indicative of a detection of a falling edge of the input signal, wherein the counter-based programmable delay subcircuit is configured to receive the information indicative of the detection of the rising edge and the information indicative of the detection of the falling edge and generate the information for generation of the pulses.
8. The phase-shifting pulse width modulation circuit of claim 7 , wherein the edge distributor block comprises a D-type flip flop, an AND gate, a first inverter, a second inverter and an OR gate,
wherein a D-input port of the D-type flip-flop is coupled to an input port to the edge distributor block, and wherein a Q-output port of the D-type flip-flop is coupled to inputs of the first inverter and the second inventor,
and wherein a first input port of the AND gate is coupled to the input port to the edge distributor block, and a second input port of the AND gate is coupled to an output of the first inverter
and wherein a first input port of the OR gate is coupled to the input port to the edge distributor block, and a second input port of the OR gate is coupled to an output of the second inverter.
9. The phase-shifting pulse width modulation circuit of claim 7 , wherein the output information indicative of a detection of a rising edge of the input signal is a first value and the information indicative of a detection of a falling edge of the input signal is a second value.
10. The phase-shifting pulse width modulation circuit of claim 9 , wherein the first value is at least one of: a ‘1’ or a value indicative of a high value or a value indicative of a value that is greater than the second value.
11. The phase-shifting pulse width modulation circuit of claim 9 , wherein the second value is at least one of: a ‘0’ or a value indicative of a low value or a value indicative of a value that is less than the first value.
12. The phase-shifting pulse width modulation circuit of claim 7 , further comprising:
an edge combiner subcircuit configured to receive the information for generation of the pulses and output the pulses.
13. The phase-shifting pulse width modulation circuit of claim 12 , wherein the edge combiner subcircuit comprises a plurality of blocks for respectively outputting the pulses, wherein at least one of the plurality of blocks comprises a D-type flip-flop, an OR gate and an AND gate,
wherein a first input port of the AND gate is coupled to a first input port of the edge combiner subcircuit and a second input port of the AND gate is coupled to a Q-output port of the D-type flip-flop,
and wherein a first input port of the OR gate is coupled to an output port of the AND gate and a second input port of the OR gate is coupled to a second input port of the edge combiner subcircuit,
and wherein a D-input port of the D-type flip-flop is coupled to an output port of the OR gate.
14. A system, comprising:
a phase-shifting pulse width modulation circuit configured to output pulses based on an input pulse width modulated signal, wherein the pulses are staggered relative to one another, the phase-shifting pulse width modulation circuit comprising a counter-based programmable delay subcircuit consisting of two counter-based programmable delay blocks; and
a light emitting diode driver configured to drive a plurality of light emitting diode strings, wherein each of the plurality of light emitting diode strings is driven by a one of the output pulses of the input width modulated signal.
15. The system of claim 14 , wherein the phase-shifting pulse width modulation circuit further comprises:
a period measurement block configured to measure a period of an input signal to the phase-shifting pulse width modulation circuit;
an edge distributor block configured to:
receive the input signal; and
output information indicative of a detection of a rising edge of the input signal and information indicative of a detection of a falling edge of the input signal, wherein the counter-based programmable delay subcircuit is configured to receive the information indicative of the detection of the rising edge and the information indicative of the detection of the falling edge and generate information for generation of the pulses.
16. The system of claim 15 , wherein the output information indicative of the detection of a rising edge of the input signal is a first value and the information indicative of the detection of a falling edge of the input signal is a second value.
17. The system of claim 16 , wherein the first value is at least one of: a ‘1’ or a value indicative of a high value or a value indicative of a value that is greater than the second value.
18. The system of claim 16 , wherein the second value is at least one of: a ‘0’ or a value indicative of a low value or a value indicative of a value that is less than the first value.
19. The system of claim 14 , wherein the phase-shifting pulse width modulation circuit is implemented in hardware.
20. The system of claim 14 , wherein the pulses are non-overlapping.