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:
Feb. 28, 1995
Filed:
Feb. 02, 1993
Ruey I Yu, Austin, TX (US);
Mark D Bader, Austin, TX (US);
Motorola Inc., Schaumburg, IL (US);
Abstract
A substrate bias generating circuit (20) provides a substrate bias voltage to a substrate (50) of an integrated circuit. A voltage-to-current converter circuit (22) provides a constant current proportional to a bandgap generated reference voltage. P-channel transistors (34 and 35) then provide constant current sources for a voltage level sensing circuit (36) based on the bandgap generated reference voltage. The voltage level sensing circuit (36) monitors the level of the substrate bias voltage, and when the substrate bias voltage reaches a predetermined voltage level, provides a first control signal for activating an oscillator (47). A level converter (43) is provided to amplify, or level convert the first control signal for more reliable control of the oscillator. A substrate bias generating circuit (20) provides a precisely controlled substrate bias voltage to the substrate (50) that is independent of process, temperature, and power supply variations.