Patent Number: 7,821,242

Title: Constant voltage circuit and method of controlling ouput voltage of constant voltage circuit

Abstract: A constant voltage circuit for converting an input voltage input from an input terminal, converting the input voltage to a predetermined constant voltage, and outputting the converted voltage from an output terminal is disclosed that includes an output transistor for outputting a current corresponding to a control signal from the input terminal to the output terminal, a control circuit part for controlling operation of the output transistor so that a proportional voltage proportional to the voltage output from the output terminal is equal to a reference voltage, and a pseudo-load current control circuit part for supplying a pseudo-load current from the output terminal when detecting that the output transistor is switched off according to a voltage difference between the input voltage and a voltage of a gate of the output transistor.

Inventors: Takagi; Yoshiki (Hyogo, JP)

Assignee: Ricoh Company, Ltd.

International Classification: G05F 1/565 (20060101)

Expiration Date: 2018-10-26 0:00:00