Vinesh Sukumar

Imaging system MTF- modeling with modulation functions

This paper introduces camera imaging module systems involving smaller pixel geometries. Lowering pixel size challenges improving system performance. In any imaging system engineering design, it is important to determine predictive response portfolio. This is studied in this paper using a theoretical model with the help of modulation functions. Predicted response of certain influencing individual subsystems of an imaging system are presented graphically using MATLAB scripts. An attempt is made to collect practical data to support these theoretical measurements. Challenges involved in these measurements are presented with recommendations for future improvement.

Smart algorithms for correcting pixel clusters in imaging applications

This paper introduces certain innovative algorithms to mask pixel defects in image sensors. Pixel defectivity rates scale with pixel architecture and process nodes. Smaller pixel and process nodes introduce more defects in manufacturing. Brief introduction to causes for pixel defectivity at lower pixel nodes is explained. Later in the paper, popular defect correction schemes used in image processing applications are discussed. A new approach for defect correction is presented and evaluated using images captured from an 8M Bayer image sensor. Experimentation for threshold evaluation is done and presented with practical results for better optimization of proposed algorithms. Experimental data shows that proposed defect corrections preserves a lot of edge details and corrects for bright and hot pixels/clusters, which are evaluated using histogram analysis.

Temperature-independent high voltage reference design in silicon-on-insulator CMOS technology

Temperature independence for voltage reference circuits designed in silicon-on-insulator CMOS technology. This design takes advantage of high-voltage devices recently developed for a 0.35 um process. This paper focuses on unique aspects of design in this process, using a voltage reference as a vehicle. The underlying circuit is a high voltage reference, designed in a diode configuration and in a MOSFET configuration. Layout considerations common to both of the circuits are outlined. Design equations are developed. Performance is characterized through SPICE simulations.

MOSFET charger controller circuit for on chip power cells in aeronautical applications

Integrated microbatteries are being currently developed to act as a “micropower” source in microsatellites. They help provide localized current capacities or embedded power supplies at the chip level, for space exploration. These power cells are designed to be rechargeable. This research paper aims at presenting charging these power cells using pulsing algorithms developed at MRCI with an on chip pulse charger controller.