Jeffrey D Stump

US Patent:

48071048, Feb 21, 1989

Filed:

Apr 15, 1988

Appl. No.:

7/182010

Inventors:

Michael D. Floyd - Austin TX
Jeffrey D. Stump - Elgin TX

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

H02M 318

US Classification:

363 59

Abstract:

A charge pump circuit and associated method is provided for outputting either a positive or a negative output voltage, or both, which each may have a predetermined magnitude which is an integer multiple of the magnitude of a power supply voltage used to power the circuit. In one form, a first capacitor is charged to the power supply voltage. The first capacitor is coupled to the power supply voltage to develop a double voltage transfer supply with the supply voltage. Second and third capacitors are charged by the double voltage transfer supply. The second capacitor is used to store the charge from the first capacitor for a continuous output voltage having a magnitude which is twice the magnitude of the power supply. The third capacitor may be reconfigured to generate a negative transfer voltage. The negative transfer voltage is used to charge a fourth capacitor which provides a negative output voltage with twice the magnitude of the power supply voltage.