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:
Sep. 27, 2022
Filed:
Feb. 23, 2021
Realtek Semiconductor Corporation, Hsinchu, TW;
REALTEK SEMICONDUCTOR CORPORATION, Hsinchu, TW;
Abstract
The present invention discloses a bias current generation circuit. An operation amplifier compares an input voltage having a zero-temperature coefficient and a feedback voltage to generate a driving voltage. An output transistor generates a bias current according to the driving voltage. A variable resistive circuit is electrically coupled to the output transistor through a feedback node to generate the feedback voltage according to the bias current and includes series-coupled resistors and switch transistors. Each of the resistors has a resistance having a positive temperature coefficient and includes a current input terminal and a current output terminal. Each of the switch transistors is electrically coupled between the current output terminal of one of the resistors and a ground terminal. One of the switch transistors turns on according to a control voltage variable according to the temperature variation to enable resistors to generate the resistance having a negative temperature coefficient.