The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 28, 2003
Filed:
Feb. 26, 2001
Yoshikazu Nishimura, Tokyo, JP;
Fuminobu Ono, Tokyo, JP;
NEC Compound Semiconductor Devices, Ltd., Kanagawa, JP;
Abstract
An active bias circuit having a combined configuration of the Wilson and Widlar current source configurations is provided, which makes it possible to set the output bias voltage at approximately 0V even if a reference voltage applied to generate a reference current does not reach 0V. This circuit comprises cascode-connected first and second transistors, cascode-connected third and fourth transistors, and a diode with a specific forward voltage drop generated by a current flowing through the diode itself. The absolute value of the output bias voltage is decreased by the value of the forward voltage drop of the diode compared with the case where the diode is not provided. The diode is provided between the source/emitter of the third transistor and the drain/collector of the fourth transistor, or between the connection point of the third and fourth transistors and the output terminal, or the gates/bases of the first and third transistors.