Delay compensation circuit
View Patent ↗An integrated circuit includes a delay compensation circuit ( 221, 222 ) that further includes a terminal for receiving a varying signal from a circuit external to the integrated circuit; a sampler circuit that samples and holds a present value of the varying signal at each occurrence of a transition in a digital signal; an integrator, coupled to the sampler circuit, that integrates a voltage difference between a sample of the varying signal and a reference signal, and that outputs results of the integration, wherein a time constant of the integrator is greater than a period of the varying signal; a waveform generator that generates a decreasing voltage in response to a transition in a second digital signal; and a comparator that has one input terminal for receiving the decreasing voltage, an inverted input terminal for receiving the results, and an output terminal for outputting a signal that generates an output signal.
1. An integrated circuit, comprising:
a delay compensation circuit, disposed on a circuit-supporting substrate, including:
a terminal for receiving a varying signal,
a sampler circuit that samples and holds a present value of the varying signal at each occurrence of a transition in a digital signal,
an integrator, coupled to the sampler circuit, that integrates a voltage difference between a sample of the varying signal and a reference signal, and outputs results of the integration, wherein a time constant of the integrator is greater than a period of the varying signal,
a waveform generator that generates a decreasing voltage in response to a transition in a second digital signal, and
a comparator that has one input terminal for receiving the decreasing voltage, an inverted input terminal for receiving the results, and an output terminal for outputting a signal that generates an output signal.
2. The integrated circuit of claim 1 , wherein a changed state of the output signal is aligned with a moment that an amplitude of the varying signal equals the reference signal.
3. An integrated circuit, comprising:
switcher logic for producing a first signal and a second signal for controlling a circuit external to the integrated circuit, and
a delay compensation circuit, coupled to the switcher logic, the delay compensation circuit including:
a sampler circuit that samples and holds a present value of a varying signal at each occurrence of a transition in the first signal, the varying signal received from the external circuit,
an integrator, coupled to the sampler circuit, that integrates a voltage difference between a sample of the varying signal and a reference level and that outputs results of integration, wherein a time constant of the integrator is greater than a period of the varying signal,
a waveform generator that generates a decreasing voltage in response to a transition in a digital signal from the switcher logic, and
a comparator that has one input terminal for receiving the decreasing voltage, an inverted input terminal for receiving the results of integration, and an output terminal for outputting a signal that generates a triggering signal,
wherein a changed state of the triggering signal is aligned with a moment that an amplitude of the varying signal equals the reference level,
wherein the switcher logic produces, in response to the changed state of the triggering signal, the first signal.
4. The integrated circuit of claim 3 , including:
a second delay compensation circuit coupled to the switcher logic for generating a second triggering signal for the switcher logic, wherein a changed state of the second triggering signal is aligned with a moment that an amplitude of the varying signal equals a second reference level, and
wherein the switcher logic produces, in response to the changed state of the second triggering signal, the second signal.
5. The integrated circuit of claim 4 , wherein the external circuit includes a first sub-circuit and a second sub-circuit, each of which having a provision for being switched on and off, wherein the external circuit produces the varying signal whose amplitude varies in response to the first sub-circuit and the second sub-circuit being switched on and off.
6. The integrated circuit of claim 5 , wherein the switcher logic, when coupled to the external circuit, controls the external circuit such that only one of the first sub-circuit and the second sub-circuit is on at any given instant of time.
7. The integrated circuit of claim 5 , wherein the external circuit is an output stage of a switched-mode power supply, and wherein the first sub-circuit includes a first power transistor and the second sub-circuit includes a second power transistor.
8. The integrated circuit of claim 5 , wherein the switcher logic produces a changed state of a first prior signal before producing a changed state of the first signal, and wherein the switcher logic produces a changed state of a second prior signal before producing a changed state of the second signal.
9. The integrated circuit of claim 8 , wherein the delay compensation circuit generates the changed state of the triggering signal in response to occurrence of the changed state of the first prior signal and in response to the amplitude of the varying signal.
10. The integrated circuit of claim 8 , wherein the second delay compensation circuit generates the changed state of the second triggering signal in response to occurrence of the changed state of the second prior signal and in response to the amplitude of the varying signal.
11. An integrated circuit, comprising:
a driver stage disposed on a circuit-supporting substrate, the driver stage including:
switcher logic, coupled a clock circuit, for producing a first signal and a second signal during each cycle of a clock signal, wherein the switcher logic produces a changed state of a third signal prior to producing a changed state of the first signal, and wherein the switcher logic produces a changed state of a fourth signal prior to producing a changed state of the second signal,
a first delay compensation circuit, coupled to the switcher logic, for producing a first triggering signal in response to the changed state of the third signal and an amplitude of an SW voltage, wherein the first triggering signal causes the switcher logic to produce the changed state of the fourth signal and the changed state of the second signal, and
a second delay compensation circuit, coupled to the switcher logic, for producing a second triggering signal in response to the changed state of the fourth signal and the amplitude of the SW voltage, wherein the second triggering signal causes the switcher logic to produce the changed state of the third signal and the changed state of the first signal.
12. The integrated circuit of claim 11 , wherein the first delay compensation circuit produces a changed state of the first triggering signal in response to a moment that a falling SW voltage passes through a first fixed DC reference voltage.
13. The integrated circuit of claim 12 , wherein the second delay compensation circuit produces a changed state of the second triggering signal in response to a moment that a falling SW voltage passes through a second fixed DC reference voltage.
14. The integrated circuit of claim 13 , in which the first delay compensation circuit includes an integrator, coupled to a sampler circuit, that integrates a voltage difference between a sampled SW voltage and the first fixed DC reference voltage, and outputs results of the integration, wherein a time constant of the integrator is greater than a period of the SW voltage.
15. The integrated circuit of claim 14 , in which the first delay compensation circuit includes:
a waveform generator that generates a decreasing voltage, and
a comparator that has one input terminal for receiving the decreasing voltage generated by the waveform generator, an inverted input terminal for receiving the results of the integration, and an output terminal for outputting a signal that generates the first triggering signal.
16. The integrated circuit of claim 11 , wherein the driver stage is a driver stage for a switched-mode power supply (SMPS), and wherein SW voltage is produced by the SMPS when the integrated circuit is coupled to the SMPS.
17. The integrated circuit of claim 16 , wherein the SMPS includes a first power transistor and a second power transistor, and wherein an amplitude of the SW voltage varies as a result of turning on and off of the first power transistor and the second power transistor.
18. The integrated circuit of claim 17 , wherein the switcher logic aligns a moment of turning on of the first power transistor and a moment of turning on of the second power transistor with a moment that the SW voltage sweeps through 0V.
19. The integrated circuit of claim 17 , wherein the first power transistor includes a first MOSFET and the second power transistor includes a second MOSFET, wherein a conducting electrode of the first MOSFET and a conducting electrode of the second MOSFET are coupled to a node, and wherein the SMPS produces the SW voltage at the node.
20. The integrated circuit of claim 19 , including:
a first buffer, for producing a first turn-on signal from the first signal, wherein the first turn-on signal is coupled to a control electrode of the first power transistor, and
a second buffer, for producing a second turn-on signal from the second signal, wherein the second turn-on signal is coupled to a control electrode of the second power transistor.