Patent ID: 6392904
Filing Date: 2002-05-21
Classification: H02M,Y02B

Abstract:
A DC/DC converter including a charge pump circuit comprising:one or more charge pump capacitors and a plurality of controllable switches connected thereto, said controllable switches being controllable by a control circuit so that said charge pump capacitor is alternatingly switched in a charging and discharge phase so hat an output voltage deviating from the input voltage of said converter is generated at the output of said converter; a first current source set to a predetermined base current located either in the discharge path of said charge pump circuit via which in the discharge phase current is supplied to said output of said converter, or in the charging path of said charge pump circuit, via which said charge pump capacitor is charged in the charging phase of said charge pump circuit; and a second current source connected in parallel to said first current source, the current of said second current source being controllable; and an output voltage regulator circuit for generating a first control signal representing the difference between a voltage characterizing said output voltage and a first reference voltage and controlling said second current source when said charge pump circuit is active so that said controllable current is reduced or increased with an increase and reduction respectively in the difference to track the voltage characterizing said output voltage in accordance with said first reference voltage; and for generating a second control signal guided to said control circuit, this signal assuming a first status when said voltage characterizing said output voltage exceeds a second reference voltage at a predetermined level above said first reference voltage, upon which said control circuit deactivates said charge pump circuit, and assumes a second status when said voltage characterizing said output voltage drops below said second reference voltage, upon which said control circuit activates said charge pump circuit.