Patent ID: 7071766

Claim:
A constant voltage generating circuit comprising: a plurality of first pnp transistors including n (an integer; 2≦n) first pnp transistors, a collector of each of the plurality of first pnp transistors being grounded, a base of a first one of the plurality of first pnp transistors being grounded, a base of a k (an integer; 2≦k≦n)-th one of the plurality of first pnp transistors being connected to an emitter of a (k−1)-th one of the plurality of first pnp transistors; a plurality of second pnp transistors including n second pnp transistors, each having an emitter area greater than that of each of the plurality of first pnp transistors, a collector of each of the plurality of second pnp transistors being grounded, a base of a first one of the plurality of second pnp transistors being grounded, a base of a k-th one of the plurality of second pnp transistors, except for another one of the plurality of second pnp transistors, being connected to an emitter of a (k−1)-th one of the plurality of second pnp transistors; primary current sources connected to the respective emitters of said plurality of first pnp transistors and the respective emitters of said plurality of second pnp transistors, except for an emitter of the first one of the plurality of second pnp transistors, to supply currents to the respective pnp transistors of said pluralities of first and second pnp transistors, two resistors being connected in series between the emitter of said first one of the plurality of second pnp transistors and the corresponding primary current source, a connection point between the two resistors being connected to the base of said another one of the plurality of second pnp transistors; and current control means including a first input terminal to which the emitter of a n-th one of the plurality of first pnp transistors is connected and a second input terminal to which the emitter of a n-th one of the plurality of second pnp transistors is connected, the current control means controlling currents from the primary current sources by outputting a control signal that controls the currents from said primary current sources so that a potential at said first input terminal and a potential at said second input terminal are the same.