The accounting of the simultaneous exposure of the low temperatures and the penetrating radiation at the circuit simulation of the BiJFET analog interfaces of the sensors
The article considers a choice of CAD system and SPICE-models for the circuit simulation of characteristics of the bipolar (BiJFET) analog integrated circuits (IC) at the exposure of the penetrating radiation (PR) and the low temperatures. The authors suggest a modified SPICE-model, which describes the nonmonotonic change of the peak drain current and the slope of the p-n junction FET (JFET) within the temperature range from −200°C to 30°C.
The analog array chip AC-1.3 for the tasks of tool engineering in conditions of cryogenic temperature, neutron flux and cumulative radiation dose effects
The array chip AC-1.3 (OJSC “Integral” Minsk, Belarus) is a base for construction of more than 20 integrated circuits (ICs) for the goals of tool engineering and diagnostics. The article presents the results obtained in experimental studies of the effects of low-temperatures (up to minus -190°C and radiation on the DC characteristics and the current gain (β) of n-p-n and p-n-p bipolar transistors and also JFETs, which contain AC-1.3 in their structure. The paper gives design recommendations for new semi custom microcircuits based on AC-1.3, operating in space conditions.
Dimensional Errors of Fixtures, Locating and Measurement Datum Features in the Stream of Variation Modeling in Machining
Machining processes are usually multi-station processes involving a large number of operations and several locating datum changes. Machining errors are thus introduced, transformed and accumulated as the workpiece is being machined. This paper introduces procedures for expressing the influence of errors in fixtures, locating datum features and measurement datum features on dimensional errors in machining. These procedures are essential in the derivation of the Stream of Variation model of dimensional machining errors using the CAD/CAPP parameters of the machining process. The linear state space form of the Stream of Variation model allows for advanced control theory achievements to be employed in formal solutions to problems in multi-station machining. Modeling procedures presented in this paper were experimentally verified in machining of an automotive cylinder head.