The application of the residue number system (RNS) to signal processors has been widespread. In the case of infinite impulse response (IIR) digital filters, the application of the method implies the continuous scaling...
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The application of the residue number system (RNS) to signal processors has been widespread. In the case of infinite impulse response (IIR) digital filters, the application of the method implies the continuous scaling of the results, as in the case of autoscale multipliers. A different method of applying the RNS technique to fixed-point arithmetics was previously proposed by the authors. For this purpose, two finite arithmetics defined with respect to two different moduli were used. A case of particular interest was considered, i.e. that of 8-bit arithmetic, in which a limited amount of memory is needed to store the isomorphism tables. An extension of the above algorithm to the case of higher dynamic ranges is considered. The approach uses a radix-p representation and requires the same isomorphism tables already defined in the case of 8-b arithmetics. The algorithm thus preserves the memory requirements. If p=128 and the wordlength is 7L+1, the 8-b processor can be used as an elementary building block of the whole multiplying structure. A 22-b multiplier is considered in detail and compared to the traditional ones with respect to the time and area requirements for a VLSI realization.< >
The authors describe an implemented task planning system for the placement of electronic components on a printed circuit board (PCB). The task planner assumes an assembly workstation which is similar to V. Scheinman...
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The authors describe an implemented task planning system for the placement of electronic components on a printed circuit board (PCB). The task planner assumes an assembly workstation which is similar to V. Scheinman's Robotworld (1987), in which a number of small two-degrees-of-freedom robots slide on a horizontal platten above the PCB. After obtaining a PCB specification, the task planner generates a feeder layout, a feeder setup, a component assembly sequence, and a motion program for each of the robots. To test the task planner, the output is simulated graphically. For relatively small PCBs, all of this occurs within minutes, enabling quick turnaround from design to manufacture.< >
The uses of tape automated bonding (TAB) at Hughes Aircraft Company are reviewed. It is noted that TAB design and manufacture is currently troubled by nonstandardization issues and technology issues. Hughes has learne...
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The uses of tape automated bonding (TAB) at Hughes Aircraft Company are reviewed. It is noted that TAB design and manufacture is currently troubled by nonstandardization issues and technology issues. Hughes has learned that the existing ASIC and memory chips are not compatible with TAB standards. Reconciliation of ILB (inner lead bond) footprints is an IC design interface, OLB (outer lead bond) is where the preliminary JEDEC standardization has begun, and the testpad socket interfacing is a third independent variable not yet resolved. A liaison with TAB vendors led to the conclusion that single-chip packaging uses of TAB are being marginally served, but that multichip module (MCM) uses are handicapped by material and process shortcomings. Rework considerations caused Hughes to request a nickel barrier metal between copper and gold layers. Current experience in attempting to define and evaluate tools necessary to support development of high-density MCM is reported. A list of the Hughes recommendations for the use of TAB and the standards that Hughes believes to be necessary for making the TAB process acceptable is presented.< >
The parameters that directly influence the design of stable, coherent and pulsed VHF/UHF sources are identified. Assuming currently available commercial technology, an attempt is made to identify the optimum frequency...
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The parameters that directly influence the design of stable, coherent and pulsed VHF/UHF sources are identified. Assuming currently available commercial technology, an attempt is made to identify the optimum frequency, for maximum range, at which systems used for animal tracking should operate. The current state of the art of pulsed VHF/UHF transmitters, using quartz crystal resonators of minimum weight and volume is reviewed together with measurements on simple oscillator and frequency multiplier circuitry. Commercial chemically etched fundamental and overtone quartz crystal oscillators in the VHF frequency band have only recently become available; the performance of these units is compared with that available from low-ESR (effective series resistance) quartz crystal oscillators operating at third overtone in the 60-100-MHz region and with frequency multiplication factors of 3-8. Areas are identified where further research and development are required.< >
A 94-GHz HEMT (high-electron-mobility transistor) mixer was designed and fabricated using a 0.1- mu m-gate HEMT device and a hybrid microwave integrated circuit. The mixer downconverts the 92-96-GHz RF to a 8-12-GHz I...
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A 94-GHz HEMT (high-electron-mobility transistor) mixer was designed and fabricated using a 0.1- mu m-gate HEMT device and a hybrid microwave integrated circuit. The mixer downconverts the 92-96-GHz RF to a 8-12-GHz IF (intermediate frequency). At 4-dBm LO (local oscillator) drive, the mixer showed 5.8-dB conversion loss, 12.4-dB noise figure, and -3.2-dBm input power at the 1-dB gain compression point. The HEMT mixer is suitable for a 94-GHz missile seeker application where available W-band LO power is extremely low. The HEMT mixer can be monolithically integrated with a HEMT low-noise amplifier to form a low-cost, small-size, and low-weight receiver front end for use in millimeter-wave smart munitions.< >
The design and implementation of a system used for real-time acquisition and monitoring of data collected at an IC manufacturing process are described. How it is used for process improvement and control is discussed. ...
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The design and implementation of a system used for real-time acquisition and monitoring of data collected at an IC manufacturing process are described. How it is used for process improvement and control is discussed. The approach taken to solve this problem can be divided into three functional areas: acquisition, monitor, and integration. The data acquisition task utilizes a touch screen terminal which is used by each inspector to enter his inspection results. Icons represent each defect category and, when a unit is rejected, the inspector touches the icon and a counter is incremented. The data monitor is an expert system which accesses these data and displays them dynamically in a status board fashion, including statistics on each lot. It checks if any inspector has rejected or accepted too many die or if any defect rate for a reject category is too high. The data integration includes an INGRES-based relational database and many report generator programs. At the end of the lot inspection, all data and warning messages related to the lot are stored in the database for later analysis.< >
The author surveys the characterization and sources of noise in digital systems. The principal methods of characterizing noise in digital systems, including jitter and bit-error rate (BER) specifications, are explaine...
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The author surveys the characterization and sources of noise in digital systems. The principal methods of characterizing noise in digital systems, including jitter and bit-error rate (BER) specifications, are explained, and the manner in which these are produced is described. The various sources of noise generated within, and coupled into, digital circuits are briefly reviewed. design guidelines for minimizing the effects of noise are then developed.
The fault-dictionary approach to isolating failures in digital circuits provides inferior isolation accuracy compared to that which is now generally attained with other isolation methods. This limitation is particular...
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The fault-dictionary approach to isolating failures in digital circuits provides inferior isolation accuracy compared to that which is now generally attained with other isolation methods. This limitation is particularly apparent when circuits which use bidirectional bus configurations are being tested. For this reason, fault-dictionary-based isolation has serious economic implications when testing digital circuits which use expensive VLSI or HSIC devices. However, by incorporating relatively minor circuit additions into the design of VLSI and HSIC devices, the normal set/scan or equivalent testability pins can additionally serve to improve actual fault-isolation accuracy. The described additions for improving fault-dictionary-based fault isolation require little semiconductor area, and one configuration even serves to prevent bus-drive conflicts.
The author presents an overview on how an integrated E/E system designed for assembly and service can help manage the automotive electronic explosion. The application of E/E system integration and modular assembly des...
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The author presents an overview on how an integrated E/E system designed for assembly and service can help manage the automotive electronic explosion. The application of E/E system integration and modular assembly design has been shown to effectively reduce the number of electronic modules and wiring harness circuits with which assembly and service must content. It is concluded that, in addition to reducing the number of boxes and wire, cost-effective assembly verification and service diagnostics can be achieved through E/E system integration when the particular requirements of assembly and service are understood and incorporated at design concept. The integrated E/E system can then transform the vehicle's E/E componentry from simply a 'passive recipient' to that of an 'active participant' within the assembly and service process.
A model is presented for predicting the cost of manufacturing printed wiring boards. The model represents manufacturing systems currently in use in the industry. The model concentrates on surface-mount technology, usi...
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A model is presented for predicting the cost of manufacturing printed wiring boards. The model represents manufacturing systems currently in use in the industry. The model concentrates on surface-mount technology, using a mixture of automatic, programmable-assembly and manual-assembly techniques. The model includes elements to account for inventory, assembly, and test and rework costs. The model also considers the effect of introducing a component type on total manufacturing cost.
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