METHOD AND APPARATUS PROVIDING LIMITING TRANSIMPEDANCE AMPLIFICATION

摘要

A limiting transimpedance amplifier (46) includes an amplifier stage (48) including a feedback resistor (RF1), a limiting diode (D1) coupled across the feedback resistor, and a stabilization diode (D3) coupled to the amplifier stage to compensate for feedback instability introduced by the limiting diode. The amplifier stage includes an input transistor (Q1) and output transistor (Q2), where the feedback resistor couples an output of the output transistor to an input of the input transistor. A stabilization voltage generator (50) is coupled to the stabilization diode (D1) to provide a stabilization voltage that causes the desired compensation. A method for providing limited transimpedance amplification includes the steps of: (a) amplifying an input current signal at an input node (54) to develop an output voltage signal at an output node (56); (b) limiting the range of the output voltage signal by providing a feedback path between the output node and the input node that includes the parallel connection of a feedback resistor (RF1) and a limiting diode (D1); and (c) compensating for instability in the output voltage signal caused by the limiting diode (D1) in the feedback path.