An Ambient-Adaptive Voltage Scaling Driver Enabling Quasi-Linear Photon Detection With 131 dB Dynamic Range in Large-Format SPAD Arrays

This paper proposes an Ambient-Adaptive Voltage Scaling (AAVS) driver for SPAD arrays that maintains quasi-linear photon detection across a wide range of illumination levels. The proposed system integrates an Adaptive Feedback-Controlled (AFC) V<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${}_{\mathbf {EX}}$</tex-math> </inline-formula> modulator that continuously senses photon flux to regulate the excess bias voltage (V<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${}_{\mathbf {EX}}$</tex-math> </inline-formula>) relative to the actual breakdown voltage (V<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${}_{\mathbf {BD}}$</tex-math> </inline-formula>), coupled with a hybrid boost converter featuring adaptive V<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${}_{\mathbf {EX}}$</tex-math> </inline-formula> calibration to generate 27.1–27.6V with sub-millivolt ripple. Measurement results demonstrate a 131 dB dynamic range (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{10}$</tex-math> </inline-formula>–<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{17}$</tex-math> </inline-formula> photons/cm<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${}^{2}\cdot $</tex-math> </inline-formula>s), 92.3% peak efficiency, and robust scalability supporting 128-SPAD arrays. The AAVS architecture enhances sensitivity under low-light conditions while effectively preventing saturation in high-light scenarios.