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. 06, 2004
Filed:
Jan. 05, 2001
Crist Y. Lu, Fremont, CA (US);
Centillium Communications Inc., Fremont, CA (US);
Abstract
An amplifier drives a Digital-Subscriber Line (DSL) using a 12-volt power supply. Ordinary low-voltage transistors for 5-volt systems are stacked together to reduce the average voltage across each transistor to below a breakdown voltage. The output stage uses p-channel and n-channel driver transistors that are coupled to differential outputs through cascode transistors. A common-mode voltage is fed back to a second stage to adjust signals for deviations in the common-mode output bias. A first stage buffers a pair of differential inputs to the second stage. The second stage uses level shifting to generate four signals to the output stage driver transistors. A pair of high-voltage signals drives the p-channel drivers while a pair of low-voltage signals drives the n-channel driver transistors. Nested miller compensation stabilizes the amplifier using capacitors between the final outputs and the four signals from the second stage and the differential signals from the first stage.