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. 10, 2001
Filed:
Sep. 25, 1998
Jeffrey E. Koelling, Dallas, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A class AB amplifier (,) is disclosed, having a first input node (402), a second input node (,), and an output node (,). A push-pull input stage (412) includes cross-coupled pairs of transistors, which form a charge current path and a discharge current path. When the voltage at the first input node (,) is greater than the voltage at the second input node (,), the amount of current drawn in the charge current path increases, and the amount of current drawn in the discharge current path decreases. When the voltage at the first input node (,) is less than the voltage at the second input node (,), the amount of current in the charge current path decreases while the amount of current in the discharge path increases. A first and fourth current mirror (,and,) are coupled to the charge current path, and a second and third current mirror (,and,) are coupled to the discharge current path. In response to increases in the amount of current drawn in the charge current path, the first current mirror (,) drives a discharge node (,) to a charge voltage, and the fourth current mirror (,) drives a charge node (,) to a charge voltage. In response to increases in the amount of current drawn in the discharge current path, the second current mirror (,) drives the discharge node (,) to discharge voltage, and the third current mirror (,) drives the charge node (,) to a discharge voltage. An output driver (,) charges the output node (,) when the charge node (,) is at the charge voltage, and discharges the output node (,) when the discharge node (,) is at the discharge voltage.