Graham & James LLP
Reference voltage generating circuit having an integrator
 A reference voltage generating circuit is provided with a reference voltage output terminal, a voltage dividing circuit that divides a voltage supplied from a power source, and an integrating circuit having a given time constant, for integrating a voltage of the divided voltage output terminal of the voltage dividing circuit and generating a reference voltage as a result of integration to the reference voltage output terminal. A high-speed charging circuit is connected to the reference voltage output terminal, for charging the integrating circuit at a high speed when the power source is turned on, to elevate a voltage of the reference voltage output terminal at a speed higher than a speed determined by the time constant of the integrating circuit. A comparator circuit compares the voltage of the divided voltage output terminal with the voltage of the reference voltage output terminal, and turns off the high-speed charging circuit when a difference between the voltage of the divided voltage output terminal and the voltage of the reference voltage output terminal becomes equal to or smaller than a predetermined level. 
Yamaha Corporation
G
G05F
inventional
Shoji Hideyuki
Yasui Yamada