| 摘要 |
PROBLEM TO BE SOLVED: To provide a CMOS class A/B output stage which provides the advantages of high speed operation, low supply voltage requirements and low quiescent current draw, resulting form the use of subthreshold biasing of output driver transistors. SOLUTION: The class A/B amplifier output stage comprises: a first output driver transistor having a source, a gate, and a drain; a second output driver transistor having a source, a gate, and a drain; the drain of the first output driver transistor being coupled to the drain of the second output driver transistor; a first high swing cascode structure coupled to the first and second output driving transistors; and a second high swing cascode structure coupled to the first and second output driving transistors, the first and second high swing cascode structures being configured to bias the first and second output driving transistors into their subthreshold operating regions. The architecture of the output stable makes it particularly suitable for use in operational amplifiers in power demanding applications, such as portable instruments, smoke detectors, sensors, or the like. COPYRIGHT: (C)2007,JPO&INPIT
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