Patent ID: 6043705
Filing Date: 2000-03-28
Classification: H02M,Y02B

Abstract:
For use in a boost converter having a boost inductor coupled between an input and an output of said boost converter and an output capacitor coupled between rails of said output, an energy storage circuit for extending a holdup time of said boost converter, comprising:a holdup capacitor coupled to a first rail of said input;a holdup switch, coupled to a second rail of said input and said holdup capacitor, capable of closing during a holdup mode to allow said holdup capacitor to discharge current into said input;a voltage stabilizing circuit, coupled between said holdup capacitor and said output capacitor, that:when said boost converter is in a normal mode, provides a substantially impeded path for charge current to flow from said output capacitor to charge said holdup capacitor, andwhen said boost converter is in an initial phase of said holdup mode, provides a substantially unimpeded path for holdup current to flow from said holdup capacitor to said output capacitor prior to said closing of said holdup switch.