Calculation method of diode junction capacitance

Abstract

The invention discloses a diode junction capacitance calculation method. The method comprises the following steps: A1, measuring an apparent capacitance value, an apparent conductivity value, an S11 parameter real part, an S11 parameter imaginary part and voltage-current of a diode; A2, calculating a real part and an imaginary part of diode impedance by using the real part and the imaginary part of the parameter S11; A3, according to the impedance relation between the two equivalent circuits of the diode, obtaining calculation formulas of junction capacitance and series resistance; A4, setting an initial junction conductance value Ginit; A5, substituting the initial junction conductance value into the junction capacitance calculation formula to obtain a current junction capacitance value; A6, substituting the current junction capacitance value and the initial junction conductance value into the series resistance calculation formula to obtain a current series resistance value, obtaining a voltage applied to the junction conductance or the junction capacitor according to a voltage-current relationship, and obtaining a current junction conductance calculation value G' according to a conductance formula; and A7, judging whether the difference value between the Ginit and the G' is smaller than a preset threshold value or not; if so, taking the current junction capacitance value as the final value of the junction capacitance; and if not, making Ginit to be equal to G', and executing the step A5 again.

Description

technical field [0001] The invention relates to the technical field of electronic components, in particular to the technical field of semiconductor devices, and in particular to a method for calculating diode junction capacitance. Background technique [0002] Usually the diode can be equivalent to figure 1 The equivalent circuit shown in (a) is composed of junction capacitance C, junction conductance G and series resistance r s composition. In a diode capacitance measurement setup, the figure 1 (b) The parallel equivalent circuit shown, that is, the diode is equivalent to parallel apparent conductance Gp and apparent capacitance Cp. Usually the idea of ​​calculating capacitance is as follows: [0003] because figure 1 (a) with figure 1 (b) The circuit is also a diode equivalent circuit, so the impedance of the two circuits is equal, that is: [0004] [0005] [0006] Among them, ω represents the frequency of the alternating current applied to the diode during ...

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Problems solved by technology

[0013] In view of this, the present invention proposes a calculation method for diode junction capacitance, which replaces ω with a measurable physical quantity, so that the junction capacitance value of a diode at any frequency can be calculated regardless of the size relationship between G and ωC, and solves the current problem The calculation method of diode junction capacitance needs to meet the preconditions and if the preconditions are not met, the calculation method is very complicated.

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