Management of regulator-induced switching noise for sampled systems
View Patent ↗A system includes a sampler to sample an input voltage and a switching regulator. The switching regulator is adapted to regulate a switching operation of the regulator in response to the sampling by the sampler.
1. A system comprising:
a sampler configured and arranged to sample an input signal and to generate a first signal that indicates that the input signal is being sampled; and
a switching regulator that is separate from the sampler and that includes at least a first switch, the switching regulator, responsive to the first signal, configured and arranged to prevent the first switch from transitioning between an open state and a closed state while the input signal is being sampled by the sampler.
2. The system of claim 1 , wherein the switching regulator is configured and arranged to prevent noise generated by the regulator from propagating into samples generated by the sampler by preventing the first switch from transitioning while the input signal is being sampled.
3. The system of claim 1 , wherein the switching regulator is coupled to the sampler through a supply rail.
4. The system of claim 1 , wherein the switching regulator further includes
a controller, that is configured and arranged to generate a second signal to control operation of the first switch to regulate an output signal of the regulator, and
a noise management circuit that is configured and arranged to receive the first signal and, responsive to the first signal, to delay the second signal in order to prevent the first switch from transitioning while the input signal is being sampled by the sampler.
5. The system of claim 4 , wherein the second signal transitions between a first level to close the first switch and a second level to open the first switch, and the noise management circuit is configured and arranged to control transitions of the second signal between the first and second levels in response to the first signal.
6. The system of claim 5 , wherein the switching regulator further includes a second switch and switching regulator is further configured and arranged to prevent the second switch from transitioning between an open state and a closed state while the input signal is being sampled by the sampler.
7. The system of claim 4 , wherein the controller is further configured and arranged to generate a third signal to control operation of the second switch to regulate the output signal of the regulator, and the noise management circuit is further configured and arranged, responsive to the first signal, to delay the third signal in order to prevent the second switch from transitioning while the input signal is being sampled by the sampler.
8. The system of claim 7 , wherein the third signal transitions between a first level to close the second switch and a second level to open the second switch, and the noise management circuit is configured and arranged to control transitions of the third signal between the first and second levels in response to the first signal.
9. The system of claim 5 , wherein the noise management circuit is configured and arranged to use the first signal to mask transitions of the second signal between the first and second levels.
10. The system of claim 5 , wherein the first signal includes a pulse train comprising pulses indicative of times at which the sampler samples the input signal, and the noise management circuit is configured and arranged to selectively delay the second signal to prevent the transitions between the first and second levels in the second signal from occurring concurrently with the pulses.
11. The system of claim 4 , wherein the noise management circuit includes a flip-flop having a clock input terminal that is configured and arranged to receive the second signal and a reset input terminal that is configured and arranged to receive the first signal.
12. A method for regulating a switching operation of a switching regulator responsive to a sampler sampling an input signal, the switching regulator including at least a first switch, the method comprising:
generating a first signal that indicates that the input signal is being sampled by the sampler;
responsive to the first signal, preventing the first switch from transitioning between an open state and a closed state while the input signal is being sampled by the sampler.
13. The method of claim 12 , wherein preventing the first switch from transitioning includes regulating transitions of a switching signal of the switching regulator between a first level and a second level in response to the first signal.
14. The method of claim 13 , further comprising:
selectively delaying the transitions of the switching signal response to the first signal.
15. The method of claim 14 , further comprising:
controlling a timing of the transitions to regulate an output signal of the switching regulator.
16. The method of claim 12 , wherein the switching regulator further includes a second switch and the method further comprising, responsive to the first signal, preventing the second switch from transitioning between an open state and a closed state while the input signal is being sampled by the sampler.
17. The method of claim 13 , further comprising:
masking the switching signal in response to the first signal.
18. The method of claim 17 , wherein masking comprises receiving a pulse train comprising pulses indicative of sample times at which the sampler samples, the method further comprising:
selectively delaying the switching signal to prevent transitions between the first and second levels in the switching signal occurring concurrently with the pulses.