Circuit for generating a DC voltage supply and a driver circuit using the DC voltage supply circuit

Abstract

A circuit is for generating a DC voltage supply from a higher voltage AC signal. A first capacitor (C1) is in series between an input (12) and a first node (N1), a first diode (D1) is in forward direction between the first node and a DC voltage supply node (Nout), a second capacitor (C2) is between the DC voltage supply node and a reference terminal, and a second diode (D2) is in forward direction between the reference terminal and the first node. This defines a general charge pump architecture. A third capacitor (C3) is then provided between the first node and a second node (N2) and a controllable voltage supply (60) defines the voltage at the second node (N2). This adjustable node voltage improves the efficiency of the circuit, in that excess current can be dissipated efficiently, and it can be implemented with a simple circuit.

Dependencies are inferred from the claim text.