A CMOS Image Sensor Dark Current Compensation Using In-Pixel Temperature Sensors †

This paper presents a novel technique for dark current compensation of a CMOS image sensor (CIS) by using in-pixel temperature sensors (IPTSs) over a temperature range from −40 °C to 90 °C. The IPTS makes use of the 4T pixel as a temperature sensor. Thus, the 4T pixel has a double functionality, either as a pixel or as a temperature sensor....

In-pixel temperature sensors for dark current compensation of a CMOS image sensor

This thesis describes the integration of temperature sensors into a CMOS image sensor (CIS). The temperature sensors provide the in-situ temperature of the pixels as well as the thermal distribution of the pixel array. The temperature and the thermal distribution are intended to be used to compensate for dark current affecting the CIS. Two...

In-Pixel temperature sensors with an accuracy of ±0.25 °C, a 3σ variation of ±0.7 °C in the spatial domain and a 3σ variation of ±1 °C in the temporal domain

This article presents in-pixel (of a CMOS image sensor (CIS) temperature sensors with improved accuracy in the spatial and the temporal domain. The goal of the temperature sensors is to be used to compensate for dark (current) fixed pattern noise (FPN) during the exposure of the CIS. The temperature sensors are based on substrate parasitic...

A CMOS-Imager-Pixel-Based Temperature Sensor for Dark Current Compensation

This brief proposes employing each of the classical 4 transistor (4T) pinned photodiode (PPD) CMOS image sensor (CIS) pixels, for both imaging and temperature measurement, intended for compensating the CISs' dark current, and dark signal non-uniformity (DSNU). The proposed temperature sensors rely on the thermal behavior of MOSFETs working in...

Compensation for Process and Temperature Dependency in a CMOS Image Sensor

This paper analyzes and compensates for process and temperature dependency among a (Complementary Metal Oxide Semiconductor) CMOS image sensor (CIS) array. Both the analysis and compensation are supported with experimental results on the CIS’s dark current, dark signal non-uniformity (DSNU), and conversion gain (CG). To model and to...

Suppression of spatial and temporal noise in a CMOS image sensor

This paper presents methodologies for suppressing the spatial and the temporal noise in a CMOS image sensor (CIS). First of all, it demonstrates by using a longer-length column bias transistor, both the fixed pattern noise (FPN) and temporal noise can be suppressed. Meantime, it employs column-level oversampling delta-sigma ADCs to suppress...

Integration of 555 temperature sensors into a 64 × 192 CMOS image sensor

In this work, a novel approach for measuring relative temperature variations across the active area of a CMOS image sensor itself is presented. 555 Image pixels have been replaced by temperature sensors pixels (Tixels) in the same pixel array layer. Both sensors, pixels and Tixels, utilize the same readout structure to obtain the data. This...

Temperature Sensors Integrated into a CMOS Image Sensor

In this work, a novel approach is presented for measuring relative temperature variations inside the pixel array of a CMOS image sensor itself. This approach can give important information when compensation for dark (current) fixed pattern noise (FPN) is needed. The test image sensor consists of pixels and temperature sensors pixels (=Tixels)....

Negative Offset Operation of Four-Transistor CMOS Image Pixels for Increased Well Capacity and Suppressed Dark Current

This letter presents an electrical method to reduce dark current as well as increase well capacity of four-transistor pixels in a CMOS image sensor, utilizing a small negative offset voltage to the gate of the transfer (TX) transistor particularly only when the TX transistor is off. As a result, using a commercial pixel in a 0.18 ?m CMOS process...