| 摘要 |
An improved amplifier architecture for providing an output as a function of light sensed by a photodetector element where the amplifier has an input for receiving the current output from the photodetector element and an output for providing an output that is a clamped function of light sensed by the photodetector element. A feedback circuit is connected between the input and the output of the amplifier. A signal clamp connected to the output of the amplifier that clamps the output of the amplifier to a predetermined value. A summing node having first, second, and third inputs, and an output at which a signal that is a function of sensed light is provided. A first current path connected between the input to the amplifier and to a first input of the summing node for passing excess current from the input of the amplifier to the summing node when the output of the amplifier is at its clamped output. Also provided is a second current path connected between the output of the amplifier and a second input to the summing node along with a reference voltage source connected to the third input to the summing node for limiting the current flowing through the second current path.
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