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:
Jul. 01, 2003
Filed:
Jun. 14, 2001
Thomas A Somerville, Tempe, AZ (US);
Praveen V. Nadimpalli, Tempe, AZ (US);
Other;
Abstract
A source follower output stage achieves low output impedance and high power supply rejection while operating at low output voltage and low supply voltage. This circuit has improved performance due to the source follower transistor, the sense transistor, and the output mirror, these items forming a common source difference amplifier. This common source difference amplifier adjusts the common voltage of the signal mirror to equalize the signal mirror input and output voltage. Thus, the common node of the mirror adapts to changing supply voltage, output load current and temperature so that the effect on source follower output voltage is minimized. Since the output node of the signal mirror is clamped to the source follower output instead of the common node of the mirror, the circuit operates at lower output and supply voltage than the prior art. For optimum performance, the current density ratio of the output mirror devices is equal to the current density ratio of the sense transistor to the source follower transistor.