Power supply circuit system

摘要

A power supply circuit system includes a ring oscillator provided with a variable resistance circuit, a charge pump circuit outputting a boosted voltage in response to an oscillation output signal from the ring oscillator, a voltage regulator circuit adjusting the boosted voltage from the charge pump circuit, a first current comparator circuit comparing a first current flowing through the voltage regulator circuit with a first reference current, a second current comparator circuit comparing the first current with a second reference current, and a control circuit outputting control signals to control a resistance value of the variable resistance circuit in accordance with a first comparison signal from the first current comparator circuit and a second comparison signal from the second current comparator circuit.

主权项

1. A power supply circuit system comprising:
an oscillation circuit configured to change an oscillation frequency thereof and outputting an oscillation output signal; a charge pump circuit outputting a boosted voltage in response to the oscillation output signal, the boosted voltage being obtained by boosting an input voltage; a voltage regulator circuit adjusting the boosted voltage from the charge pump circuit to a predetermined voltage; a control circuit outputting a control signal controlling the oscillation circuit so that the oscillation frequency of the oscillation circuit is increased when a first current flowing through the voltage regulator circuit is smaller than a first reference current, the oscillation frequency of the oscillation circuit is decreased when the first current is larger than a second reference current, and the oscillation frequency of the oscillation circuit is maintained when the first current is between the first reference current and the second reference current, the second reference current being larger than the first reference current; and the voltage regulator circuit including an operational amplifier and a first transistor, a reference voltage being applied to a first input terminal of the operational amplifier and a voltage corresponding to the boosted voltage being applied to a second input terminal of the operational amplifier, the first transistor being controlled by an output of the operational amplifier, and the first current flowing through the first transistor.