An Angle-Insensitive 138-dB Dynamic Range Light Sensor With 4 Time-Interleaved Channels 32-ppm/°C Temperature-Independent Flicker Detection

This brief presents an angle-insensitive, high dynamic range light sensor with 4-channels (CHs) temperature-independent flicker detection. Angle insensitivity is achieved by two pairs of Dual-Photodiodes (PDs) for X-axis and Y-axis respectively. 4-CHs temperature-independent flicker detection is realized by a time-interleaved architecture sharing two Trans-Impedance-Amplifiers (TIAs) and one 16-bit third-order incremental $\Delta \Sigma $ ADC, whose clock provided by a newly proposed relaxation oscillator with real-time comparator offset and current-mirror mismatch temperature variation calibration. 7-Levels Auto-Gain-Control (AGC) is implemented to extend dynamic range. The chip was fabricated using 180nm CMOS technology. Experiment results show that the proposed light sensor can achieve −30°~30° flat angular response with +/−67° field-of-view (FOV). 4-CHs flicker detection with 32ppm/°C temperature coefficient is achieved in the range of −30~85°C. 7-Levels AGC extends input light dynamic range to 138dB (0.012~103klux). The chip power consumption is 0.39mW under 1.8V supply and chip area is 2mm x 0.65mm.