Variable Frequency Charge Pump

摘要

A charge pump circuit that utilizes a sensing circuit for determining the current loading or status of the output supply generated by the charge pump circuit to determine a corresponding frequency for a variable rate clock for the charge pump circuit. When a current load is present, the clock frequency automatically ramps up to a relatively high level to increase the output current of the charge pump circuit. When the current load is removed and the supply is settled out, the clock frequency is automatically reduced to a relatively quieter level and the charge pump circuitry operates at a lower power level. Accordingly, the charge pump circuit is only noisy when it has to be, thus providing optimal power when required and being electrically quiet and operating at lower power at all other times.

主权项

1. A variable frequency charge pump circuit, including:
(a) at least one charge pump having a clock signal input, a voltage supply input, and an output, each for providing a pumped output voltage at the corresponding output based on a regulated input voltage applied at the corresponding voltage supply input, with a current available at the corresponding output as a function of the frequency of a signal applied to the corresponding clock signal input; (b) at least one feedback circuit, each coupled to the output of a corresponding charge pump, each feedback circuit for providing a feedback signal indicative of the pumped output voltage at such output; and (c) at least one charge pump regulator and variable frequency clock circuit, each coupled to a voltage source, the voltage supply input and the clock signal input of a corresponding charge pump, and the feedback signal of the feedback circuit corresponding to such charge pump, each charge pump regulator and variable frequency clock circuit for generating and providing both (1) the regulated input voltage to the voltage supply input of the corresponding charge pump in response to such feedback signal to regulate the pumped output voltage at the output of the corresponding charge pump, and (2) a variable-frequency clock signal generated in response to such feedback signal separately from the generation of the regulated input voltage and provided to the clock signal input of the corresponding charge pump to control the amount of current available at the output of the corresponding charge pump; wherein, for each one of the at least one charge pumps, as a load at the output of such one charge pump increases, the frequency of the provided clock signal increases and the current available at the output of such one charge pump increases, and as the load decreases, the frequency of the provided clock signal decreases and the current available from such one charge pump decreases.