Showing papers on "Junction temperature published in 1980"

Thermal Resistance: A Reliability Consideration

Abstract: The importance of the mean operating temperature of a monolithic integrated circuit encapsulated in a molded plastic package and its relation to the reliability of that component is reviewed. A thermal model of a plastic package is described and experimentally verified. The model is applied to measure chip or junction temperature under operating conditions, and errors which can be introduced are discussed.

Temperature sensing circuit for semiconductor junction temperature probe

Abstract: The temperature probe is biased for causing current flowing therethrough to be proportional to the probe temperature. A variable set point temperature is represented by a variable reference current which is summed with the temperature probe current. An output signal is produced therefrom to indicate the relationship between the set point temperature and the probe temperature.

Planar, fast, reliable, single-heterojunction light-emitting diodes for optical links

Abstract: The properties, fabrication and performance of planar (i.e., without an etched well), single heterojunction Ga 1–x Al x As:Te − GaAs:Ge fast LEDs, developed for use in optical data links, are discussed in this paper. The LEDs consist totally of epitaxially grown material. Current confinement achieved by contact area restriction increases current density and localizes electroluminescence for efficient coupling into a fiber. The peak wavelength of emission is at ≈900 nm with a full width at half-maximum of ≈50 nm. Electroluminescent rise and fall times are ≈3 ns each with pre-bias, making these LEDs adequate for data transmission rates as high as 100 Mb/s. At 700 A/cm2, the LEDs launch 100 μW of optical power into a 0.36 numerical aperture (NA) and 125-μm core-diameter, step-index fiber or 10 μW into a 0.23 NA, 55-μm core-diameter, graded-index fiber. The LEDs are highly reliable with extrapolated mean time to failure of 2.7 × 107 hours at junction current density of 700 A/cm2 and junction temperature of 74°C. These LEDs have been used as sources in prototype subsystems under development for use in electronic switching systems.

Temperature-stabilized logarithmic converter

Abstract: A logarithmic converter circuit comprising an emitter-coupled pair of transistors and a pair of operational amplifiers is provided with a temperature-stabilized environment so that accurate logarithmic conversion is facilitated. One of the pair of transistors is utilized as a temperature sensor to provide a temperature control voltage, which in turn controls the power applied to a heating element disposed adjacent the pair of transistors to maintain a constant semiconductor junction temperature. The heating element may suitably be one or more transistors disposed proximate the pair of transistors on a common substrate. The absolute temperature of the sensor transistor base-to-emitter junction is established by the use of precise gain-setting components, and by adjusting the temperature reference voltage for the correct system gain.

Analysis of a junction termination structure for ideal breakdown voltage in p-n junction devices

Abstract: Electric-field distribution and avalanche breakdown voltage in reverse-biased p-n junction devices having a concave p-n junction termination structure are analyzed by a two-dimensional numerical method. It is shown that there are two peaks in the electric field of the device. One peak, near the p-n junction edge, is smaller than the other peak, found in the one-dimensional region, so that an ideal breakdown voltage can be obtained. This desirable feature comes partly from the excessive spreading of the depletion layer around the p-n junction edge due to the concave junction shape. One of the merits of this junction termination structure is that the allowable range of device parameters for the ideal breakdown voltage is much wider than for any other junction termination structure. Experimental breakdown voltage of a diode with the concave p-n junction structure agrees well with the ideal breakdown voltage calculated in the one-dimensional region of the device.

Electrothermal transients due to self heating in a silicon p-n diode

Abstract: The method of calculating the junction-temperature response and the nonisothermal transient i/v characteristics for a silicon forward-biased p-n diode is presented in this paper. The proposed method is based on the iterative calculation procedure, in which a diode is assumed to be subjected to a current or voltage waveform. This is in contrast with other methods, in which a temperature-indepenmdent power-input function, seldom met in practice, is assumed. As an example, calculations of the voltage across the diode and of the junction temperature for some given current inputs i(t) have been performed according to the presented method, and the results are discussed.