Photodiode Amplifier with Transimpedance and Differential Stages for Automotive Visible Light Applications

To address the most common issues found in automotive Visible Light Communication applications, a new photodiode amplifier based on an instrumentation amplifier is proposed. In order to improve the results, buffer stages have been replaced with transimpedance amplifiers providing the circuit with offset cancellation loops that enable the sensing of the DC output offset and with T-networks in the feedback path, that reduce the effect of parasitic capacitances. Thus, the resulted output signal will be ready for further processing in the analog-digital conversion (ADC) stage providing improved results in terms of parasitic light resilience and SNR.