Abstract:
This letter presents an ultralow-noise, power-efficient, and pulse-width modulation (PWM)-dimming-tolerant photocurrent readout circuit for under-display ambient light sensor (ALS). A transimpedance amplifier (TIA) with a feedback diode achieves G $\Omega $ -level resistance and 6 fA/ $\surd $ Hz input current noise, enabling sub-pA resolution. Instability and noise folding are mitigated at …