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:
May. 02, 2000
Filed:
Jan. 14, 1999
Ping Xu, Milpitas, CA (US);
Seiko Epson Corporation, Tokyo, JP;
Abstract
A symmetrical analog power amplifier employing CMOS technology comprising an input stage and an improved output stage having a pull up/down arrangement to provide improved operating characteristics. The amplifier includes a pair of input transistors that receive an input signal and a node on which a first output voltage is generated. The amplifier further includes an improved output stage comprising an intermediate current source circuit that includes a first current source transistor, a control transistor and a second current source transistor connected in series. A first output voltage is generated on a node interconnecting the control transistor and the second current source transistor. A second output voltage, which is responsive to the first output voltage, is generated on a node connecting the first current source transistor and the control transistor. The output stage further includes a first output transistor responsive to the first output voltage and a second output transistor responsive to the second output voltage. A third output voltage, which is the output voltage of the amplifier, is generated on an output node interconnecting the first and second output transistors. A power down circuit may be embodied in the amplifier to reduce its power consumption.