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A 640×512 CMOS image sensor with an 8b bit-serial Nyquist rate ADC per 4 pixels achieves 10.5 × 10.5 µm pixel size at 29% fill factor in 0.35 µm CMOS technology. Binary floating point output with measured dynamic range of of 65536 : 1 is achieved by multiple sampling at exponentially increasing exposure times. 1 Dynamic range, defined as the ratio of the(More)
Bubble-based actuation in microfluidic applications is attractive owing to elementary microfabrication requirements. In the present study, the mechanical and chemical characteristics of electrochemically generated bubble valves were studied. By generating electrochemical bubbles as valves directly inside the channel, valves could be closed and opened in(More)
The standard method for measuring QE for a CCD sensor is not adequate for CMOS APS since it does not take i n to consideration the random ooset, gain variations, and nonlinearity i n troduced by the APS readout circuits. The paper presents a new method to accurately estimate QE of an APS. Instead of varying illumination as in the CCD method, illumination is(More)
A CMOS 64 × 64 pixel area image sensor chip using Sigma-Delta modulation at each pixel for A/D conversion is described. The image data output is digital. The chip was fabricated using a 1.2µm two layer metal single layer poly n-well CMOS process. Each pixel block consists of a phototransistor and 22 MOS transistors. Test results demonstrate a dynamic range(More)
The standard method for measuring QE for a CCD sensor is not adequate for CMOS APS since it does not take into consideration the random offset, gain variations, and nonlinearity introduced by the APS readout circuits. The paper presents a new method to accurately estimate QE of an APS. Instead of varying illumination as in the CCD method, illumination is(More)
Dynamic range is a critical figure of merit for image sensors. Often a sensor with higher dynamic range is regarded as higher quality than one with lower dynamic range. For CCD and CMOS sensors operating in the integration mode the sensor SNR monotonically increases with the signal. Therefore, a sensor with higher dynamic range, generally, produces higher(More)
1. ABSTRACT A set of test structures designed to characterize and compare the performance of CMOS passive and active pixel image sensors is presented. The test structures are designed so that they can be rapidly ported from one process to another. They are also designed so that individual photodetectors and pixel circuits as well as entire image sensor(More)