Charge pump having ramp rate control

• Main Authors: Cook, Thomas D, Cunningham, Jeffrey C, Ramanan, Karthik
• Format: Patent
• Language: English; French; German
• Published: 11.01.2017
• Subjects: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC,OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWERSUPPLY SYSTEMS; CONTROL OR REGULATION THEREOF; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUTPOWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION

A charge pump (30) includes a first counter (18) and a pump stage (20). The first counter (18) has a control input for receiving a control signal, and an output for providing a first count value. The first count value is incremented in response to the control signal being a first logic state and the first count value is decremented in response to the control signal being a second logic state. The pump stage (20) has a variable capacitor. The variable capacitor has a control input coupled to the output of the first counter (18) for receiving the first count value. The capacitance value of the variable capacitor is changed in response to the first count value changing. The capacitance value is for determining a ramp-up rate of an output voltage (Vout) at an output of the charge pump (30).