Slew-controlled switched capacitors for ac-dc applications

Abstract

In a power converter, a regulator that receives a first voltage couples to a switched-capacitor converter that provides a second voltage. Slew-control circuitry controls slew rate within the switched-capacitor converter during operation thereof. A controller controls the operation of both the regulator and the switched-capacitor converter.

Having described the invention, and a preferred embodiment thereof, what is claimed as new, and secured by Letters Patent is: 
     
         1 - 69 . (canceled) 
     
     
         70 . An apparatus comprising an AC-DC converter, the AC-DC converter comprising:
 a power conversion circuit to receive a first voltage at a first terminal and to provide a second voltage at a second terminal based, at least in part, on the first voltage, the power conversion circuit comprising:
 a controller to provide one or more control signals and to receive one or more feedback signals based, at least in part, on the one or more control signals, the controller to include one or more input/output terminals; 
 a regulator to be coupled to the first terminal and to a third terminal, the third terminal to be maintained at an intermediate voltage different from the first voltage or the second voltage; and 
 a switched-capacitor converter to be coupled to the regulator via the third terminal, the switched-capacitor converter to be further coupled to the second terminal providing the second voltage, 
   wherein the controller to control the regulator and the switched-capacitor converter based, at least in part, on at least one of the following: the one or more control signals; one or more input/output signals; or any combination thereof, the one or more input/output signals to be communicated via the one or more input/output terminals.   
     
     
         71 . The apparatus of  claim 70 , further comprising a bridge rectifier to be coupled to the regulator, the bridge rectifier to transform an AC voltage into the first voltage to be received by the regulator. 
     
     
         72 . The apparatus of  claim 71 , further comprising an active power-factor control circuit to be coupled between a pre-regulator and the bridge rectifier. 
     
     
         73 . The apparatus of  claim 70 , wherein the switched-capacitor converter comprises a plurality of capacitors to be alternately connected to at least a first group of switches or a second group of switches to respectively implement one or more switching patterns via one or more switching frequencies so as to transfer charge between at least some of the plurality of capacitors, the one or more switching patterns to be implemented to achieve different voltage conversion ratios. 
     
     
         74 . The apparatus of  claim 73 , wherein the one or more feedback signals to be used, at least in part, by the controller to adjust the one or more switching frequencies of the first group of switches or the second group of switches responsive to one or more measurements of: a voltage within the AC-DC converter, a current within the AC-DC converter, or any combination thereof. 
     
     
         75 . The apparatus of  claim 70 , wherein the regulator comprises an isolated regulator or non-isolated regulator. 
     
     
         76 . The apparatus of  claim 75 , wherein the isolated regulator comprises a magnetically isolated regulator or a galvanically isolated regulator. 
     
     
         77 . The apparatus of  claim 76 , wherein the magnetically isolated regulator comprises a fly-back converter, a forward converter, a half-bridge converter, or a full-bridge converter. 
     
     
         78 . The apparatus of  claim 77 , wherein the fly-back converter comprises a quasi-resonant fly-back converter, an interleaved fly-back converter, a two-switch fly-back converter, or an active-clamp fly-back converter. 
     
     
         79 . The apparatus of  claim 77 , wherein the forward converter comprises a multi-resonant forward converter, an active-clamp forward converter, or a two-switch forward converter. 
     
     
         80 . The apparatus of  claim 77 , wherein the half-bridge converter comprises an asymmetric half-bridge converter, a multi-resonant half-bridge converter, or an LLC resonant half-bridge converter. 
     
     
         81 . The apparatus of  claim 75 , wherein the non-isolated regulator comprises a boost converter, a buck converter, or a buck-boost converter. 
     
     
         82 . The apparatus of  claim 70 , wherein the switched-capacitor converter comprises a single-stage switched-capacitor circuit having at least one bypass switch to transition, during operation of the AC-DC converter, between switch states so as to implement different voltage conversion ratios of the switched-capacitor converter. 
     
     
         83 . The apparatus of  claim 70 , wherein the switched-capacitor converter comprises a multi-stage switched-capacitor circuit having at least bypass switches to transition, during operation of the AC-DC converter, between switch states to switch one or more stages into or out of the multi-stage switched-capacitor circuit so as to implement different voltage conversion ratios. 
     
     
         84 . The apparatus of  claim 70 , wherein the switched-capacitor converter comprises a cascade multiplier. 
     
     
         85 . The apparatus of  claim 70 , wherein the switched-capacitor converter comprises an adiabatic switched-capacitor converter or a diabatic switched-capacitor converter. 
     
     
         86 . The apparatus of  claim 70 , wherein the switched-capacitor converter comprises a multi-phase network. 
     
     
         87 . The apparatus of  claim 70 , wherein the switched-capacitor converter comprises a ladder network, a Dickson network, a series-parallel network, a Fibonacci network, a doubler network, or any combination thereof. 
     
     
         88 . The apparatus of  claim 70 , wherein the regulator comprises a transformer. 
     
     
         89 . The apparatus of  claim 88 , wherein the transformer comprises an air-core transformer. 
     
     
         90 . The apparatus of  claim 70 , wherein the controller to comprise at least a primary side section, a secondary side section, and an isolation barrier between the primary side section and the secondary side section. 
     
     
         91 . The apparatus of  claim 70 , wherein at least the power conversion circuit is to be incorporated into a travel adapter. 
     
     
         92 . The apparatus of  claim 91 , wherein the travel adapter comprises an AC-DC adapter. 
     
     
         93 . The apparatus of  claim 91 , wherein the travel adapter comprises a universal serial bus port to be maintained at the second voltage. 
     
     
         94 . The apparatus of  claim 91 , wherein the switched-capacitor converter to operate in discrete steps so as to provide coarser voltage regulation relative to voltage regulation to be provided by the regulator. 
     
     
         95 . An apparatus comprising:
 a wireless charging system for use with an AC-DC converter, the wireless charging system comprising:
 a first coil coupled to a frequency converter, the frequency converter to convert a first frequency to a second frequency to facilitate wireless energy transfer by the first coil; and 
 a second coil to wirelessly receive energy from the first coil, the second coil to be positioned in proximity to the first coil so as to form an air-core transformer, the air-core transformer to provide a first voltage to a first stage of the AC-DC converter based, at least in part, on the wireless energy transfer, 
   wherein the first stage to provide a third voltage to a second stage of the AC-DC converter, the second stage to output a second voltage based, at least in part, on charge transfer between capacitors of the second stage responsive to one or more switching patterns of one or more switches of a plurality of switches controllable to switch between the switching patterns according to one or more switching frequencies, and   wherein a controller is to control operation of the first and the second stages.   
     
     
         96 . The apparatus of  claim 95 , wherein the first stage comprises a regulator and the second stage comprises a switched-capacitor converter. 
     
     
         97 . The apparatus of  claim 96 , wherein:
 the capacitors of the second stage are a plurality of capacitors of the switched-capacitor converter; and   the plurality of capacitors are to be interconnected via the one or more switches of the plurality of switches.   
     
     
         98 . The apparatus of  claim 95 , further comprising a bridge rectifier to be disposed to transform an AC voltage into the first voltage, the bridge rectifier to be coupled to one or more additional circuitries. 
     
     
         99 . The apparatus of  claim 98 , wherein the one or more additional circuitries comprise: a fuse disposed to prevent excess current within the apparatus, an active power-factor corrector, or an electromagnetic interference filter disposed to suppress radiation generated during operation of the AC-DC converter. 
     
     
         100 . The apparatus of  claim 98 , wherein the bridge rectifier and the one or more additional circuitries to be disposed in a base station or in a portable electronic device. 
     
     
         101 . The apparatus of  claim 98 , and further comprising an AC source for providing the AC voltage. 
     
     
         102 . The apparatus of  claim 101 , wherein the AC source is a component of the wireless charging system. 
     
     
         103 . The apparatus of  claim 101 , wherein the AC source to include a base station comprising the first coil coupled to the frequency converter. 
     
     
         104 . The apparatus of  claim 95 , and further comprising an additional bridge rectifier to be disposed in a base station or in a portable electronic device. 
     
     
         105 . The apparatus of  claim 95 , wherein the third voltage comprises an intermediate voltage. 
     
     
         106 . The apparatus of  claim 105 , wherein the intermediate voltage is lower than the first voltage.