scholarly journals Determination of transient thermal characteristics for thermal electric behavioral models of integrated circuits

2020 ◽  
Vol 9 (3) ◽  
pp. 933-942
Author(s):  
Drakin A. Yu ◽  
Potapov L. A. ◽  
Shkolin A. N.
Keyword(s):  
Integrated Circuits ◽  
Least Squares Method ◽  
Thermal Characteristic ◽  
Thermal Characteristics ◽  
Structural Function ◽  
Behavioral Models ◽  
Marquardt Algorithm ◽  
Thermoelectric Model ◽  
Transient Thermal

In the current study, it was tried to describe a method for determining thermal characteristics of integrated micro-circuits to identify thermal parameters of multidisciplinary (thermal-electric) behavioral models. The problem is solved on the example of high-frequency pulse voltage converters. A solution was proposed to refine the minimum structure of the thermoelectric model based on an iterative least squares method using the Levenberg-Marquardt  algorithm, as well as a graph of the spectral den-sity of time constants. This made it possible to reduce the influence of the filtering factor in the  deconvolution operation when building a thermal model using the structural function of the thermal characteristic transition. Also, the results obtained can be used to build integrated circuits (IC) behavioral models, taking into account the thermal processes occurring in them.

ANALYSIS OF METHODS FOR DETERMINING AND APPLYING HEAT PARAMETERS OF HIGH FREQUENCY PULSE VOLTAGE CONVERTERS

2019 ◽  
Author(s):  
Leonid Potapov ◽  
Aleksey Shkolin
Keyword(s):  
High Frequency ◽  
Reference Data ◽  
Supply Voltage ◽  
Thermal Characteristic ◽  
Pulse Voltage ◽  
Electrical Parameters ◽  
Cooling Conditions ◽  
Thermoelectric Model ◽  
Transient Thermal ◽  
Frequency Pulse

It is shown that the thermal resistance of the junction-case is determined through a partial heat flux and is some characteristic of the crystal fastening in the case of high-frequency pulse voltage converters. It is practically impossible to measure this resistance in mass production because of the high complexity and low accuracy, although this resistance is indicated in the reference data sheet for each IC. To exclude the possibility of hidden defects that are not detected during the control of electrical parameters, it is proposed to use one hundred percent control of thermal parameters by way of comparison with a standard. The transient thermal characteristic can be determined experimentally for a specific IC and specific cooling conditions. After approximation by its exponents, it is possible to construct a thermoelectric model and use it to study the change in the temperature of the IC chip with changing various parameters (supply voltage, load power, etc.).

scholarly journals THE MEASUREMENT OF THERMAL PARAMETERS BY CHANGING FREQUENCY OF EMBEDDED RING OSCILLATOR

2021 ◽  
Vol 63 (1) ◽  
pp. 82-90
Author(s):  
Iaroslav G. Tetenkin ◽  
◽  
Viacheslav A. Sergeev ◽  
Keyword(s):  
Integrated Circuits ◽  
Thermal Characteristics ◽  
Simple Algorithm ◽  
Numerical Differentiation ◽  
Thermal Parameters ◽  
Ring Oscillator ◽  
Equivalent Circuits ◽  
Digital Integrated Circuits ◽  
Software Complex ◽  
Transient Thermal

The article describes a brief analysis of linear thermal models of digital integrated circuits (DIC) and algorithms for determining the parameters of thermal equivalent circuits of DIC-based on transient thermal characteristics (TTC). It distinguishes the difficulties in implementing the algorithm for determining the thermal parameters of the DIC-based on the method of structure functions according to the JESD51-14 document and describes a new method for measuring the FPGA TTC by changing the frequency of a ring oscillator embedded in the FPGA logic elements. It also considers the hardware-software complex used for measuring the thermal parameters of FPGAs and proposes a simple algorithm for calculating the thermal parameters of FPGAs based on the analysis of the FPGA TTC using methods of numerical differentiation. The specified algorithm for calculating thermal parameters has been tested on the example of FPGA TTC EPM240T100C5 and Lattice M4A5-64/32.

scholarly journals Effects of operating and material parameters on the thermal characteristics of a wet clutch

2021 ◽  
Vol 13 (7) ◽  
pp. 168781402110341
Author(s):  
Zhigang Zhang ◽  
Ling Zou ◽  
Hang Liu ◽  
Yonglong Chen ◽  
Benzhu Zhang
Keyword(s):  
Heat Flux ◽  
Applied Pressure ◽  
Thermal Characteristics ◽  
Thermal Models ◽  
Material Parameters ◽  
Heat Transfer Theory ◽  
Friction Disk ◽  
Viscous Shear ◽  
Wet Clutch ◽  
Transient Thermal

Based on the frictional mechanism of a wet clutch, frictional models of wet clutch engagement were established using the modified Reynolds equation and the elastic contact model between frictional pairs. Then, the heat flux models for the viscous shear and asperity friction were built, and the two-dimensional transient thermal models for the separator plate, friction disk, and ATF heat convection model were deduced based on the heat transfer theory and conservation law of energy. Finally, the Runge–Kutta numerical method was used to solve the frictional and thermal models. The average temperature of the separator plate, friction disk, and ATF were calculated. The effects of operating and material parameters, such as applied pressure, initial angular velocity, friction lining permeability, surface combined roughness RMS, equivalent elastic modulus, and ATF flow, on the thermal characteristics of friction pairs and ATF during engagement, were studied. The simulation results show that the temperature characteristics of the separator plate, friction disk, and ATF depend mainly on the viscous shear and asperity friction heat flux, and that the operating and material parameters of the wet clutch also have significant impacts on the overall variation trend of the thermal characteristics of the separator plate, friction disk, and ATF.

scholarly journals Design and thermal characteristic analysis of motorized spindle cooling system

2021 ◽  
Vol 13 (5) ◽  
pp. 168781402110208
Author(s):  
Yuan Zhang ◽  
Lifeng Wang ◽  
Yaodong Zhang ◽  
Yongde Zhang
Keyword(s):  
Flow Rate ◽  
High Speed ◽  
Thermal Deformation ◽  
Cooling System ◽  
Thermal Characteristic ◽  
Water Flow Rate ◽  
Thermal Characteristics ◽  
Characteristic Analysis ◽  
Motorized Spindle ◽  
Experiment And Simulation

The thermal deformation of high-speed motorized spindle will affect its reliability, so fully considering its thermal characteristics is the premise of optimal design. In order to study the thermal characteristics of high-speed motorized spindles, a coupled model of thermal-flow-structure was established. Through experiment and simulation, the thermal characteristics of spiral cooling motorized spindle are studied, and the U-shaped cooled motorized spindle is designed and optimized. The simulation results show that when the diameter of the cooling channel is 7 mm, the temperature of the spiral cooling system is lower than that of the U-shaped cooling system, but the radial thermal deformation is greater than that of the U-shaped cooling system. As the increase of the channel diameter of U-shaped cooling system, the temperature and radial thermal deformation decrease. When the diameter is 10 mm, the temperature and radial thermal deformation are lower than the spiral cooling system. And as the flow rate increases, the temperature and radial thermal deformation gradually decrease, which provides a basis for a reasonable choice of water flow rate. The maximum error between experiment and simulation is 2°C, and the error is small, which verifies the accuracy and lays the foundation for future research.

Measurement and Analysis on Transient Thermal Characteristics of High Speed Motorized Spindle

2011 ◽  
Vol 52-54 ◽  
pp. 2021-2026
Author(s):  
Gui Ling Deng ◽  
Can Zhou
Keyword(s):  
High Speed ◽  
Thermal Deformation ◽  
Thermal Characteristics ◽  
Measuring System ◽  
Test Results ◽  
Motorized Spindle ◽  
Measurement And Analysis ◽  
Turning Center ◽  
Transient Thermal ◽  
Deformation Compensation

Thermal deformation is an important factor to affect the accuracy of the motorized spindle, the core component of high-speed machine tool. To understand the spindle system transient thermal characteristics of the high-speed turning center CH7516GS, some high-precision sensors and high-frequency data acquisition system is used to establish the temperature and displacement measuring system. The thermal deformation compensation model is established on the basis of the experimental test results.

scholarly journals Thermal impedance at the interface of contacting bodies: 1-D examples solved by semi-derivatives

2012 ◽  
Vol 16 (2) ◽  
pp. 623-627 ◽  
Author(s):  
Jordan Hristov
Keyword(s):  
Heat Conduction ◽  
Fractional Calculus ◽  
Half Time ◽  
Thermal Impedance ◽  
Entire Domain ◽  
Transient Thermal ◽  
Two Bodies

Simple 1-D semi-infinite heat conduction problems enable to demonstrate the potential of the fractional calculus in determination of transient thermal impedances of two bodies with different initial temperatures contacting at the interface ( x = 0 ) at t = 0 . The approach is purely analytic and uses only semi-derivatives (half-time) and semi-integrals in the Riemann-Liouville sense. The example solved clearly reveals that the fractional calculus is more effective in calculation the thermal resistances than the entire domain solutions.

A least squares method for earthquake mechanism determination using S-wave data

1964 ◽  
Vol 54 (6A) ◽  
pp. 2037-2047
Author(s):  
Agustin Udias
Keyword(s):  
Least Squares ◽  
Statistical Evaluation ◽  
Least Squares Method ◽  
Numerical Approach ◽  
Focal Mechanisms ◽  
Least Square ◽  
S Wave ◽  
Double Couple ◽  
Earthquake Mechanism

abstract In this paper a numerical approach to the determination of focal mechanisms based on the observation of the polarization of the S wave at N stations is presented. Least-square methods are developed for the determination of the orientation of the single and double couple sources. The methods allow a statistical evaluation of the data and of the accuracy of the solutions.

Sign in / Sign up

Export Citation Format

Share Document