CN103293390B

CN103293390B - A kind of test circuit of power MOSFET device series inductance

Info

Publication number: CN103293390B
Application number: CN201310219744.8A
Authority: CN
Inventors: 温景超; 王立新
Original assignee: Beijing Zhongke Newmicrot Technology Development Co Ltd
Current assignee: Beijing Zhongke Newmicrot Technology Development Co., Ltd.
Priority date: 2013-06-04
Filing date: 2013-06-04
Publication date: 2016-02-03
Anticipated expiration: 2033-06-04
Also published as: CN103293390A

Abstract

The invention discloses a kind of test circuit of power MOSFET device series inductance, belong to semiconducter device testing technical field.Described test circuit comprises pulse producer, phase place display, LCR table, resistance and gating switch; The signal end of pulse producer is electrically connected with grid; The earth terminal of pulse producer is electrically connected with the stiff end of gating switch by resistance in series; Two selecting sides of gating switch are electrically connected with draining with source electrode respectively; The earth terminal ground connection of pulse producer; One end of LCR table is electrically connected with grid, and the other end is electrically connected with the stiff end of gating switch; Phase place display voltage input end is electrically connected with grid, and current input terminal is electrically connected with the stiff end of gating switch.The present invention not only can provide important parameter index for the performance of evaluator part, and is all significant for the switching characteristic of the design of optimizing power MOSFET element, raising device.

Description

A kind of test circuit of power MOSFET device series inductance

Technical field

The present invention relates to semiconducter device testing technical field, particularly a kind of test circuit of power MOSFET device series inductance.

Background technology

Power MOSFET device has a wide range of applications in field of switches with superior performances such as its high frequency, low driving powers, easily parallel connection, and wherein the parasitic component of device inside can affect the switching characteristic of device.Fig. 1 is power MOSFET device switch equivalent model schematic in prior art, contains the important parasitic component affecting devices switch performance in model.Wherein, source series inductance L _swith drain series inductance L _dit is the important parameter determining device switching speed, their size directly affects the switch performance of device, be mainly manifested in: the existence of source series inductance can affect the discharge and recharge time of device input capacitance, especially device trunon delay time and turn-off delay time; The negative feedback that source series inductance produces can cause grid current and drain electrode di/dt to set up mobile equilibrium, causes devices switch capability error; Drain series inductance not only can make drain-source voltage produce overshoot, also can increase turn-off power loss.Due to the source electrode of power MOSFET device and drain series inductance value smaller, add the impact of device parasitic electric capacity, therefore LCR cannot be used to show directly to measure, thus accurately cannot obtain the source series inductance L of power MOSFET device _swith drain series inductance L _d.

Summary of the invention

The problem of power MOSFET device series inductance directly cannot be accurately measured in order to solve prior art, the invention provides a kind of test circuit of power MOSFET device series inductance, its test philosophy is the RLC series circuit formed according to power MOSFET device endoparasitism composition and RLC series circuit resonance principle, a sine pulse is applied at device grids, regulate sine pulse frequency size, found the tuning-points of circuit simultaneously by the current phase measured in rlc circuit both end voltage and circuit; When circuit reaches resonance, according to resonance frequency now and the capacitance adopting the measurement of LCR table, the inductance value in circuit can be calculated; The series inductance of power MOSFET device source electrode and drain electrode is calculated respectively by controlling gating switch.Test circuit comprises pulse producer, phase place display, LCR table, resistance and gating switch; The signal end of described pulse producer is electrically connected with grid; The earth terminal of described pulse producer is electrically connected with the stiff end of gating switch by resistance in series; Two selecting sides of described gating switch are electrically connected with draining with source electrode respectively; The earth terminal ground connection of described pulse producer; One end of described LCR table is electrically connected with grid, and the other end is electrically connected with the stiff end of gating switch; The voltage input end of described phase place display is electrically connected with grid, and current input terminal is electrically connected with the stiff end of gating switch.

Described pulse producer is sinusoidal wave pulse generator.

Described phase place display is oscillograph.

The test circuit of power MOSFET device series inductance provided by the invention, can the serial inductance of measured power MOSFET element source electrode and drain electrode scientifically and rationally by gating switch, overcome the problem that prior art directly cannot accurately measure power MOSFET device series inductance, so not only can provide important parameter index for the performance of evaluator part, and the switching characteristic of the design of optimizing power MOSFET element, raising device is all significant.

Accompanying drawing explanation

Fig. 1 is prior art power MOSFET device switch equivalent model schematic;

Fig. 2 is prior art RLC series resonant circuit figure;

Fig. 3 is the test circuit schematic diagram of embodiment of the present invention power MOSFET device series inductance.

Embodiment

Below in conjunction with drawings and Examples, technical solution of the present invention is further described.

Fig. 2 is RLC series resonant circuit figure in prior art.Series resonance refers to that the voltage and current of studied series circuit part reaches same-phase, i.e. the induction reactance of inductance and the capacitive reactance numerically equal of electric capacity in circuit, thus makes studied circuit present pure resistance characteristic.Frequency corresponding during resonance is resonance frequency f _r, its expression formula is:

f_{r} = f \sqrt{\frac{X_{C}}{X_{L}}} = \frac{1}{2 π \sqrt{L C}} - - - (1)

In above formula, X _cand X _lbe respectively the capacitive reactance of electric capacity and the induction reactance of inductance in series resonant circuit.When RLC series resonant circuit is for producing resonance, adjustable power pulse frequency f, inductance L or electric capacity C, make its frequency reach resonance frequency f _r, and have nothing to do with resistance.

The embodiment of the present invention utilizes power MOSFET device switch equivalent model, in conjunction with RLC series resonant circuit principle, provides a kind of test circuit of power MOSFET device series inductance, as shown in Figure 3.This circuit comprises sinusoidal wave pulse generator, oscillograph, LCR table, resistance R ₀(R ₀for measuring the sample resistance of electric current) and gating switch S.Wherein, the signal end of sinusoidal wave pulse generator is electrically connected with grid; The earth terminal of sinusoidal wave pulse generator is by resistance in series R ₀be electrically connected with the stiff end of gating switch S; Two selecting sides of gating switch S are electrically connected with draining with source electrode respectively; The earth terminal ground connection of sinusoidal wave pulse generator; One end of LCR table is electrically connected with grid, and the other end is electrically connected with the stiff end of gating switch; Oscillographic voltage input end is electrically connected with grid, and current input terminal is electrically connected with the stiff end of gating switch.In actual applications, sinusoidal wave pulse generator can select TektronixAFG2021-SC, and oscillograph can select TektronixMSO2014B, and LCR table can select Agilent4285A.

Below in conjunction with the test circuit shown in Fig. 3, set forth the test process of power MOSFET device series inductance in detail, specific as follows:

After installing measured power MOSFET element (DUT), first gating switch S is adjusted to 1 position, now grid and source electrode two ends form RLC series resonant circuit; Utilize sinusoidal wave pulse generator to apply sine pulse to two ends, device gate source, by current phase (Y2 end) in oscillograph monitoring rlc circuit both end voltage phase place (Y1 end) and circuit, regulate the frequency f of sine pulse ₁until voltage-phase is identical with current phase, namely circuit reaches resonance (f ₁=f _r); Now, LCR table is adopted to test the capacitance C at two ends, grid source ₁, then according to formula (1), namely calculate source series inductance value L _s, namely again gating switch S is adjusted to 2 positions, finds resonance frequency f as stated above ₂=fr, and the capacitance C testing grid leak two ends ₂, then according to formula (1), namely calculate drain series inductance value L _d, namely

L_{D} = \frac{1}{4 π^{2} f_{2}^{2} C_{2}} .

The test circuit of the power MOSFET device series inductance that the embodiment of the present invention provides, can the serial inductance of measured power MOSFET element source electrode and drain electrode scientifically and rationally by gating switch, overcome the problem that prior art directly cannot accurately measure power MOSFET device series inductance, so not only can provide important parameter index for the performance of evaluator part, and the switching characteristic of the design of optimizing power MOSFET element, raising device is all significant.

Above-described specific embodiment; object of the present invention, technical scheme and beneficial effect are further described; be understood that; the foregoing is only specific embodiments of the invention; be not limited to the present invention; within the spirit and principles in the present invention all, any amendment made, equivalent replacement, improvement etc., all should be included within protection scope of the present invention.

Claims

1. a test circuit for power MOSFET device series inductance, is characterized in that, comprises pulse producer, phase place display, LCR table, resistance and gating switch; The signal end of described pulse producer is electrically connected with grid; The earth terminal of described pulse producer is electrically connected with the stiff end of gating switch by resistance in series; Two selecting sides of described gating switch are electrically connected with draining with source electrode respectively; The earth terminal ground connection of described pulse producer; One end of described LCR table is electrically connected with grid, and the other end is electrically connected with the stiff end of gating switch; Described phase place display voltage input end is electrically connected with grid, and current input terminal is electrically connected with the stiff end of gating switch.

2. the test circuit of power MOSFET device series inductance as claimed in claim 1, it is characterized in that, described pulse producer is sinusoidal wave pulse generator.

3. the test circuit of power MOSFET device series inductance as claimed in claim 1, it is characterized in that, described phase place display is oscillograph.