| 摘要 |
A cascode stage includes a gain boost circuit arrangement in a folded cascode type of operational amplifier. The gain boost circuit arrangement improves the overall DC gain of the operational amplifier while maintaining good low noise performance with the resistive loads. The cascode stage includes a current mirror circuit, resistive loads, and a regulated (or gain boosted) cascode circuit. The resistive loads are arranged to minimize thermal noise, while the regulated cascode circuit is arranged to increase the output impedance of a current mirror The increased output impedance results in higher DC gain in the operational amplifier. The increased DC gain and low noise characteristics may be implemented in bipolar and FET technologies.
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