This paper presents a high-speed and high-resolution On-Chip Oscilloscope (OCO) for Auto-Peak-Power Controller (APPC) and Peak-Current Detector in voltage mode Direct Time-of-Flight(DToF) driver. The OCO supports both optical input and electrical input, with front-end circuit of TIA and PGA respectively. The front-end circuit bandwidth is up to 2GHz to support 500ps pulse width detection. The optical input is for detecting VCSEL peak power, and feedback to the integrated Boost Converter to adjust VCSEL supply voltage to find the target peak optical power. The electrical input is for detecting the VCSEL peak current to avoid driver over-current, by preventing APPC from adapting to excessive peak current due to abnormal VCSEL or PD. The front-end circuit is followed by an 11-bit asynchronous logic SAR-ADC with up to 40MHz sampling rate. The OSC time accuracy is 6.6ps and detected pulse width is up to 12.8ns. The chip was fabricated in BCD180nm process. According to the test results, the measured waveform of OCO is comparable with commercial oscilloscope. By turning on the OCO-based APPC feature, the variation of optical power is controlled within 3% in the temperature range of 25-85°C.

This paper presents an angle-insensitive light sensor by means of two pairs of Dual-Photodiodes (PDs) for X-axis and Y-axis direction respectively. A time-interleaved architecture is proposed to support 4-Channels (CHs) simultaneous flicker detection, sharing two Trans-Impedance-Amplifiers (TIAs) and one 16-bit third-order incremental Δ∑ADC. 7-Levels Auto-Gain-Control (AGC) is implemented to extend dynamic range and Dark-PD is introduced to track and cancel temperature-dependent offset. The chip was fabricated using 180nm CMOS technology. Test results show that the proposed light sensor achieves −30°∼30° flat angular response with +/−67° field-of-view (FOV). AGC extends input dynamic range to 138dB(0.012∼103klux), with linearity error of 0.169%. Up to 610Hz 4-Channels flicker can be detected in parallel at 0.053lux light input. Dark offset variation is controlled within +/−1.2LSB in the range of −30°C∼85°C. The chip draws 212uA from 1.8V supply and chip area is$2\text{mm}\times 0.65\text{mn}$.

Silicon photodetectors, such as photodiode (PD), are extensively used in optical sensing as their proper performance and low cost to achieve screen brightness adjustment, ambient light flicker detection, and other functions. With the rise of under-screen optical sensing, PD is no longer sufficient for low-light level light detection and real-time low light level flicker detection. While an emerging detector, single photon avalanche diode (SPAD), shows its advantage to ultralow light sensing. However, SPAD tends to saturate at high light levels, which limits its widespread application. To inspire ambient light sensor design and address these issues, this paper proposes a high sample per second (SPS), wide dynamic range (DR) and ultralow illuminance detection SPAD array system on chip (SoC). A$16\times 16$SPAD array architecture along with counter and charge-pump is designed in 180nm BCD process to sense 100μdux ambient light at 660nm. On-chip FFT processor of 2048 points with 32-bit accuracy is realized to process sampled optical waveform for flicker detection. Besides, an area-efficient integrated charge pump is implemented to regulate high-voltage (19~25V) to SPADs with on-chip digital auto-gain control (AGC), which improves the optical DR from 87db to 123db. This work extends the optical sensing range significantly and demonstrates the effectiveness of the proposed SoC with systematical measurements.

This paper demonstrates a ranging sensor system with a configurable array of$16 \times 16$single photon avalanche diodes (SPADs), a 940nm vertical cavity surface-emitting laser (VCSEL), a co-design VCSEL driver with tunable widths from 400ps to 3630ps full-width at half-maximum (FWHM) optical pulses and peak power from 30mW to 170mW, and an embedded core to implement adaptive optical power control and distance extraction. An adaptive optical power control and a shifted bins binning of the histogram (SBbH) method to achieve high-precision distance measurement both at short-range and long-range. We achieved a minimum distance of 20mm with an absolute error better than 20% (4mm), still with a precision better than 10mm at 7m. All of results are obtained with 80% reflectivity of target at 100 frame rate.

This paper presents a batteryless DC-DC boost converter for thermoelectric energy harvesting application. With a stepping-up architecture and by inductor sharing, only one off-chip inductor is employed. Fabricated in 0.18μm CMOS process, the chip can be cold-started at 190mV and sustain operation with a minimum input voltage of 50mV. Zero-current switching (ZCS) and maximum power point tracking (MPPT) techniques are utilized to enhance the measured peak efficiency to 60%. And the output voltage can be regulated from 1V to 1.6V.