Dual-Range Transimpedance Amplifier With Linearized Wide Dynamic Range

The patent divides the single transimpedance amplifier output into two separate output channels with different gain levels. A first output provides high gain for low-level light signals, while a second output provides low gain for high-level light signals. This segmentation allows the system to handle both low-level and high-level light signals simultaneously without saturation, effectively extending the dynamic range while maintaining measurement precision for both signal levels.

The patent applies different gain qualities to different output channels rather than uniformly amplifying all signals. The first output channel is optimized with high gain specifically for low-level light signals, while the second output channel uses low gain for high-level signals. This local differentiation of gain quality allows each channel to operate optimally for its intended signal level, extending dynamic range without degrading the noise performance of either channel.

The patent dynamically selects different gain levels for different output channels based on the input signal level. The first output channel dynamically provides high gain when appropriate for low-level signals, while the second output channel dynamically provides low gain for high-level signals. This dynamic gain selection maintains a linear relationship between input current and output voltage for both channels across the extended dynamic range, avoiding the nonlinearities introduced by prior art methods.