Fast, non-monte-carlo estimation of transient performance variation due to device mismatch

This paper describes an efficient way of simulating the effects of device random mismatch on circuit transient characteristics, such as variations in delay or in frequency. The proposed method models DC random offsets as equivalent AC pseudo-noises and leverages the fast, linear periodically time-varying (LPTV) noise analysis available from RF circuit simulators. Therefore, the method can be considered as an extension to DC match analysis and offers a large speed-up compared to the traditional Monte-Carlo analysis. Although the assumed linear perturbation model is valid only for small variations, it enables easy ways to estimate correlations among variations and identify the most sensitive design parameters to mismatch, all at no additional simulation cost. Three benchmarks measuring the variations in the input offset voltage of a clocked comparator, the delay of a logic path, and the frequency of an oscillator demonstrate the speed improvement of about 100-1000x compared to a 1000-point Monte-Carlo method

Analog Design Implementation Of Usb2.0 On-The-Go Attach Detection Protocol

As the technology advancement, mobile phone or hand-held devices nowadays are equipped with extra features which accelerate the power consumption. Hence, battery life span is becoming a huge concern to all consumers. Recently, many efforts have been made to reduce power consumption as well as increase battery life span, USB2.0 On-the-Go is part of them. However, besides technical specification, there is no circuit implementation being published to date. Furthermore, with current architecture available in Intel, it has limitation on supporting high capacitance devices such as, Embedded Host. To solve the above problem, new circuitries is being proposed and designed under 45 nm CMOS process technology with 1.8 V standard power supply. The functionality of the circuits are being modeled and simulated by using SPICE simulator. Analysis are done by observing the transient simulation result as the ADP is more concerned on the charging voltage level and charging time. The proposed design is further verified by reliability test which simulates the circuit with PVT variations. The PVT conditions are ±10% variation on 1.8 V typical power supply, temperature ranges from -40℃ to 110℃ and 13 different process skews. It can be observed that the new proposed circuitries met the functionality which is described by the USB organization. Besides, the performance of the proposed circuitry is reasonably good under the above PVT variation. With such a huge PVT variation, current source is still able to meet the specification given, which is 1.1 mA to 1.65 mA. Hence, it can be concluded that the proposed design of ADP front-end circuitry met both functionality and reliability requirements

Lightning Imaging Sensor (LIS) for the Earth Observing System

Not only are scientific objectives and instrument characteristics given of a calibrated optical LIS for the EOS but also for the Tropical Rainfall Measuring Mission (TRMM) which was designed to acquire and study the distribution and variability of total lightning on a global basis. The LIS can be traced to a lightning mapper sensor planned for flight on the GOES meteorological satellites. The LIS consists of a staring imager optimized to detect and locate lightning. The LIS will detect and locate lightning with storm scale resolution (i.e., 5 to 10 km) over a large region of the Earth's surface along the orbital track of the satellite, mark the time of occurrence of the lightning, and measure the radiant energy. The LIS will have a nearly uniform 90 pct. detection efficiency within the area viewed by the sensor, and will detect intracloud and cloud-to-ground discharges during day and night conditions. Also, the LIS will monitor individual storms and storm systems long enough to obtain a measure of the lightning flashing rate when they are within the field of view of the LIS. The LIS attributes include low cost, low weight and power, low data rate, and important science. The LIS will study the hydrological cycle, general circulation and sea surface temperature variations, along with examinations of the electrical coupling of thunderstorms with the ionosphere and magnetosphere, and observations and modeling of the global electric circuit