| 摘要 |
This document describes systems and methods for providing an automatic gain control transimpedance interface apparatus for a photodiode. In one example, the interface apparatus includes a cascade of at least one gain stage. A voltage signal is fed back from a noninverting output of the at least one cascaded gain stage to a preceding noninverting input of the at least one cascaded gain stage. Another voltage signal is fed back from an inverting output of the at least one cascaded gain stage to a preceding inverting input of the at least one cascaded gain stage. The feedback configuration is believed to reduce peaking and/or pole shifting as the AGC varies the gain of the at least one gain stage. The AGC improves dynamic range utilization. One example provides a gain stage with a single pole frequency response and omits emitter-follower buffers between gain stages that produce hidden poles.
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