CN101598750A - A kind of measuring method of chip power-consumption - Google Patents

Abstract

A kind of measuring method of chip power-consumption comprises the steps: the application scenarios of chip to be measured is arranged to meet or the environment of approximate JEDEC standard; With chip energising work certain hour to be measured, use chip operation to be measured stable; Measure the shell temperature of chip to be measured and the temperature of chip surrounding air environment to be measured respectively; With the shell temperature of the chip to be measured that measured and the temperature of chip surrounding air environment to be measured, the substitution following formula calculates the power consumption of chip to be measured.P=(T _C-T _A)/(θ _JA-θ _JC* α), θ in the formula _JA, θ _JCWith α be the intrinsic parameter of chip, can provide by the chip data or by chip supplier; T _CShell temperature for chip; T _ABe near the air ambient temperature chip.The present invention has the voltage and current without measured chip, and the temperature of the gentle chip surrounding air environment of shell when only working by measured chip just can obtain the advantage of chip power-consumption size.

Description

A kind of measuring method of chip power-consumption

Technical field

The present invention relates to a kind of measuring method of the dissipation power consumption that is used for measured chip, especially for the measuring method of the very little chip power-consumption of the relative general power of output power.

Background technology

Chip power-consumption method of testing commonly used is the supply voltage and the electric current of test chip, calculate the power consumption of chip then, but, this chip power-consumption method of testing commonly used is for being difficult to by measuring voltage and electric current, chip as BGA encapsulation or multivoltage power supply, will be by measuring directly its voltage and current data, its difficulty is very big.Therefore, conventional chip power consumption test method and be not suitable for the power consumption test of this class chip.

Summary of the invention

The objective of the invention is to overcome the problems referred to above, provide a kind of measurement of avoiding the voltage and current of chip to society, the temperature of the gentle chip surrounding air environment of shell when only working by measured chip just can obtain the measuring method of chip power-consumption size.

Principle of the present invention is: required parameter when generally chip can be stipulated high workload junction temperature and obtain junction temperature to calculate, for the calculating of junction temperature dual mode is arranged usually, and promptly calculate junction temperature and by chip shell temperature calculating junction temperature by environment temperature.

At first calculating junction temperature by environment temperature is defined by following expression.

T _j=T _A+ θ _JA* P (formula one)

T in the formula _jRepresent the junction temperature of chip; T _ARepresent near the air ambient temperature of chip; θ _JAThe thermal resistivity of expression from the knot of chip to surrounding environment; P is the dissipated power of chip.

The junction temperature of chip also can calculate by the shell temperature of chip in addition.

T _j=T _C+ θ _JC* P _C(formula two)

T _CShell temperature for chip; θ _JCThe thermal resistivity of expression from the knot of chip to shell; P _CExpression chip dissipation power consumption has by the part that shell distributes

P _C=α * P (formula three)

Wherein α be one greater than 0 less than 1 coefficient.

With the P in above-mentioned formula one, formula two and the formula three _CAnd T _jCancellation can get formula four:

$P=\frac{T_C-T_A}{{\mathrm{\θ}}_{\mathrm{jA}}-{\mathrm{\θ}}_{\mathrm{jC}}\×\mathrm{\α}}$ (formula four)

θ in the following formula denominator _JA, θ _JCWith α be the intrinsic parameter of chip, can provide by the chip data or by chip supplier; The shell temperature that so just can be by measured chip and the temperature computation of chip surrounding air environment go out the dissipation power consumption of chip.

When the utilization said method was measured power consumption, the application scenarios of chip will meet or approximate JEDEC standard, promptly chip to be measured near do not have the existence of other high power device, so just can draw result more accurately.

Specifically, measuring method of the present invention comprises the steps:

1, a kind of measuring method of chip power-consumption is characterized in that, comprises the steps:

(1), the application scenarios of chip to be measured is arranged to meet or the environment of approximate JEDEC standard;

(2), with chip energising work certain hour to be measured, use chip operation to be measured stable;

(3), measure the shell temperature of chip to be measured and the temperature of chip surrounding air environment to be measured respectively;

(4), with the shell temperature of the chip to be measured that measured and the temperature of chip surrounding air environment to be measured, the substitution following formula calculates the power consumption of chip to be measured

$P=\frac{T_C-T_A}{{\mathrm{\θ}}_{\mathrm{jA}}-{\mathrm{\θ}}_{\mathrm{jC}}\×\mathrm{\α}}$

θ in the following formula _JA, θ _JCWith α be the intrinsic parameter of chip, can provide by the chip data or by chip supplier; T _CShell temperature for chip; T _ABe near the air ambient temperature chip.

The present invention has the voltage and current without measured chip, and the temperature of the gentle chip surrounding air environment of shell when only working by measured chip just can obtain the advantage of chip power-consumption size.

Embodiment

With PMC-Sierra, the electronic switch chip PM8385 chip of Inc company is an example, its thermal resistivity θ _JAUnder calm situation 32.48 ℃/W, θ _JB(the expression chip is from tying the thermal resistivity of chip bottom) is 23.7 ℃/W, θ _JT(i.e. θ above _JC) be 8.5 ℃/W.

Then

$\mathrm{\α}=\frac{{\mathrm{\θ}}_{\mathrm{jB}}}{{\mathrm{\θ}}_{\mathrm{jB}}+{\mathrm{\θ}}_{\mathrm{jT}}}=0.736$

Under the application conditions that meets the JEDEC standard substantially, measure the shell temperature T of chip _CBe 61 ℃, the chip environments temperature T _ABe 32.2 ℃, the chip ambient air temperature when the chip environments temperature refers to chip operation.

Then

$P=\frac{T_C-T_A}{{\mathrm{\θ}}_{\mathrm{jA}}-{\mathrm{\θ}}_{\mathrm{jC}}\×\mathrm{\α}}$

$=1.1W$

And the chip power-consumption that the voltage and current of actual measurement chip under same condition of work calculates is 1.2W.Two results are very approaching.

Claims (1)

1, a kind of measuring method of chip power-consumption is characterized in that, comprises the steps:

(1), the application scenarios of chip to be measured is arranged to meet or the environment of approximate JEDEC standard;

(2), with chip energising work certain hour to be measured, use chip operation to be measured stable;

(3), measure the shell temperature of chip to be measured and the temperature of chip surrounding air environment to be measured respectively;

(4), with the shell temperature of the chip to be measured that measured and the temperature of chip surrounding air environment to be measured, the substitution following formula calculates the power consumption of chip to be measured

$P=\frac{T_C-T_A}{{\mathrm{\θ}}_{\mathrm{jA}}-{\mathrm{\θ}}_{\mathrm{jC}}\×\mathrm{\α}}$

θ in the following formula _JA, θ _JCWith α be the intrinsic parameter of chip, can provide by the chip data or by chip supplier; T _CShell temperature for chip; T _ABe near the air ambient temperature chip.