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:
Jun. 12, 2007
Filed:
Jan. 18, 2005
Tom Peter Edward Broekaert, Thousand Oaks, CA (US);
Michael Case, Thousand Oaks, CA (US);
Tom Peter Edward Broekaert, Thousand Oaks, CA (US);
Michael Case, Thousand Oaks, CA (US);
Inphi Corporation, Westlake Village, CA (US);
Abstract
A bipolar high impedance element comprises a p-n diode made from a compound semiconductor, and circuitry arranged to reverse-bias the diode such that the diode conducts a nearly constant current—thereby enabling the element to be employed as a high impedance element. The diode is preferably the base-emitter junction of a transistor made from a compound semiconductor like InP, such that an on-chip high impedance element is provided for a fabrication process such as that used for HBTs. The element is suitably employed in an active low pass filter design: the element is connected between an input signal and an op amp input, and a feedback capacitor is connected between the op amp's output and input. The resulting filter's time constant varies with the reverse-biased diode's impedance and the capacitance of the feedback capacitor.