System and method for providing power via a spurious-noise-free switching device

Abstract

A switching power converter includes a converter input configured to receive a first electrical signal, and a converter output configured to supply a second electrical signal at a desired voltage. The switching power also converter includes a control circuit for controlling one or more switches to produce the desired voltage. The control circuit is configured to control the one or more switches using one of pulse-frequency modulation and pulse-width modulation, such that an oscillating signal is generated using a combination of random frequency-hopping and random phase-chopping.

What is claimed is: 
     
         1 . A switching power converter comprising:
 a converter input configured to receive a first electrical signal;   a converter output configured to supply a second electrical signal at a desired voltage; and   a control circuit for controlling one or more switches to produce the desired voltage;   wherein the control circuit is configured to control the one or more switches using one of pulse-frequency modulation and pulse-width modulation, such that an oscillating signal is generated using a combination of random frequency-hopping and random phase-chopping.   
     
     
         2 . The switching power converter of  claim 1 , wherein the control circuit for controlling the one or more switches is configured to generate the oscillating signal as a series of pulse trains, wherein each pulse train includes an integer number of cycles of a corresponding frequency. 
     
     
         3 . The switching power converter of  claim 2 , wherein the control circuit is configured to generate pulse trains of randomly switching frequency, of randomly switching duty cycle, or of randomly switching frequency and duty cycle. 
     
     
         4 . The switching power converter of  claim 3 , wherein the control circuit is configured to randomly switch from a first frequency to a second frequency such that the ratio of the first frequency multiplied by the integer number of cycles of its pulse train to the second frequency equals a rational number that is not an integer. 
     
     
         5 . The switching power converter of  claim 4 , wherein the control circuit is configured to generate a series of pulse trains of exactly two different frequencies. 
     
     
         6 . The switching power converter of  claim 4 , wherein the control circuit is configured to generate a series of pulse trains, wherein each pulse train in the series of pulse trains is exactly one cycle at its corresponding frequency. 
     
     
         7 . The switching power converter of  claim 3 , wherein the control circuit is configured to randomly switch from a first frequency to a second frequency such that the ratio of the first frequency to the second frequency equals a rational number that is not an integer. 
     
     
         8 . The switching power converter of  claim 2 , wherein the control circuit comprises at least one of a constant-width pulse generator and a ramp generator, each configured to supply the oscillating signal. 
     
     
         9 . The switching power converter of  claim 8 , wherein the ramp generator has two inputs for two reference voltages, the ramp generator further including a ramp output coupled to an input of a PWM comparator, wherein an output of the PWM comparator provides a control signal for the one or more switches. 
     
     
         10 . The switching power converter of  claim 9 , wherein the ramp generator comprises:
 a plurality of current sources, each current source corresponding to a unique ramp output frequency;   a counter whose output determines the integer number of cycles in each pulse train; and   a random number generator whose output determines which current source of the plurality of current sources generates the pulse train.   
     
     
         11 . The switching power converter of  claim 8 , wherein the constant-width pulse generator includes an input coupled to an output of a PFM comparator, and wherein an output of the constant-width pulse generator provides a control signal for the one or more switches. 
     
     
         12 . The switching power converter of  claim 11 , wherein the constant-width pulse generator comprises:
 a plurality of current sources, each current source corresponding to a unique ramp output frequency;   a counter whose output determines the integer number of cycles in each pulse train;   a random number generator whose output determines which current source of the plurality of current sources generates the pulse train; and   a delay circuit configured to generate a signal that determines a pulse-width of each pulse in the series of pulse trains.   
     
     
         13 . The switching power converter of  claim 1 , wherein the converter input is configured to receive one of an AC signal, and a combined AC and DC signal. 
     
     
         14 . The switching power converter of  claim 1 , wherein the control circuit is configured such that the second electrical signal has a voltage equal to or less than the voltage of the first electrical signal. 
     
     
         15 . The switching power converter of  claim 1 , wherein the control circuit is configured such that the voltage of the second electrical signal can be any value but with a polarity opposite that of the first electrical signal. 
     
     
         16 . The switching power converter of  claim 1 , wherein the control circuit is configured such that the second electrical signal has a voltage equal to or greater than the voltage of the first electrical signal. 
     
     
         17 . The switching power converter of  claim 1 , further comprising an error amplifier and compensation network connected in a feedback loop between the converter output and the control circuit for controlling the one or more switches. 
     
     
         18 . The switching power converter of  claim 17 , wherein a voltage of the second electrical signal is determined by a reference signal provided to the error amplifier and compensation network. 
     
     
         19 . The switching power converter of  claim 1 , wherein the control circuit is configured such that the oscillating signal transitions between three distinct voltage levels. 
     
     
         20 . The switching power converter of  claim 1 , further comprising:
 one or more switching elements configured to receive an output of the control circuit; and   an energy storage element coupled between the one or more switching elements and the generator output.   
     
     
         21 . The switching power converter of  claim 20 , further comprising a driver stage coupled between the output of the control circuit and the one or more switching elements. 
     
     
         22 . The switching power converter of  claim 20 , wherein the one or more switching elements comprise two transistors connected in series, wherein two outputs of the control circuit are coupled to respective gates or bases of the two transistors, and wherein the energy storage element is connected at a point of connection between the two transistors. 
     
     
         23 . The switching power converter of  claim 22 , wherein the control circuit comprises:
 a first output and a second output, each comprising an output of respective first and second gate drive circuits;   a first flip flop whose output drives the first gate drive circuit; and   a second flip flop whose output drives the second gate drive circuit and also provide an input, via a first time delay circuit, to the first flip flop.   
     
     
         24 . The switching power converter of  claim 23 , wherein the control circuit has an input coupled to a first input of the second flip flop, and coupled to a second input of the flip flop, via a second time delay circuit.