Power semiconductor of the switching power supply Dave Ross Blog

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In the past more than 20 years, some new power semiconductor switching Hall effect current sensor element and module of power have appeared, here like the power MOS-FET, insulated-gate bipolar transistor IGBT, carborundum SiC Device field have at various degrees new development following MOSFET, IGBT, IGCT,etc. that have not mark out especially, refer to making with the silicon wafer .


In 1979, the power MOSFET field effect transistor came out. Because and heat good stability that its input impedance high, switch is fast, can totally replace the power transistor GTR and crystal gate tube in the middle trickle, make it possible to realize high frequency in electric electronic circuit such as switching power supply. Its quota of electric current of voltage has already reached 500V/240 A, 1500V/200 A. The characteristic of the power MOSFET is that a switching loss is little, but the on-state power consumption is large, and UB the higher the spark-over voltage of the power MOSFET is, on-state resistance RDS on It is the bigger. Take power MOSFET of ideal nchannel as examples, on-state resistance RDS on And there are the following relations in spark-over voltage UB:

In 1989, Infineon Company put out the cold MOS tube Cco1 MCGFET ,It has adopted and formed Super-Junction superly Structure, so also called the power MOSFET in the super junction, working voltage is 600- 800V, the on-state resistance nearly reduces a order of magnitude, but still keep the quick characteristic of the switch speed, it is a kind of high-frequency power semiconductor switching element with development prospect.

2Insulated-gate bipolar transistor IGBT

1982, B.J.Ba1iga put bipolar transistor and technology, MOSFET of power, together, succeed in, develop – an insulated-gate bipolar transistor, named IGT Insulated Gate Transistor ,The international electric and electronic circle was generally called GBT Insu1ated Gate Bipo1ar Transistor later . It MOS gate electrode ‘ Grid Output functions characteristics goods fine to fail characteristic and bipolar transistor people integrate to form together. Its on-state pressure drop is small, the current density is large, can well replace the asking the tube brilliantly of the power transistor GTR and middle trickle, become a generally acknowledged a kind of electric electronic semiconductor switching element that has the development prospect most.

Compromise in the technical progress of IGBT, actually on-state pressure drop, fast switch and high pressure tight ability. The gate electrode structure of IGBT has two kinds of flush types and groove styles. With the difference between craft and structural style, here In the historical development process for many years, IGBT developed has the following types: Perforans PT Type, non- perforans NPT Type, soft perforans SPT Type, endPS in ditch slot type and electric field Type wait. The future thrust of IGBT is: Inverse-impedance type IGBT module, reducing and losing people’s electric current distortion; The best module association, reduce the on-state noise; Control the ability of du/dt and di/dt, reduce the noise to launch.

It is reported, when IGBT appears, the rated value of the electric current of voltage has 600V/25 A only. The pressure tight levels are all limited in 1200- 1700 V during very long period, pass long-time exploration Current transducer research and transform, the rated value of the electric current of voltage of IGBT has already reached 3300V/1200 A, 4500V/1800AL,etc. now, the withstand voltage of the high-pressure IGBT one piece even reaching 6500V. The working upper frequency limit of general IGBT is 20- 40 kHz. On the basis of PT structure, employ IGBT that the new technology makes, can work in 150kHz hard switching And 300 kHz soft switch .

3Integrated tube IGCT under brilliant in current conversion gate electrode

Integrated gate-commutated thyristor Integrated Gate Commutation Thyristor It is high-current switching element of a new kind of upper voltage that appeared in 1977, were abbreviated as IGCT. It utilize the intersection of power and advantage of MOSFET, technology MOS, and tube make up among being brilliant. Its loss ratio turn-off thyristor is GTO low, the interstar connection is simpler and reliabler than GTO, and can adopt air-cooledly. Have already begun to apply to the electric and electronic frequency change speed regulating system of the medium-and-large-sized power now, such as the frequency converter of MW grade, new resting type reactive power compensating device,etc..

The parameter of 4500V/4000 A IGCT is pressed forward and lowered to 2.7V, di/dt for operating frequency 1kHz =1000A / s.

4Carborundum power semiconductor switching element

Carborundum SiC Si1icon Carbide It is the ideal material of the power semiconductor switching element crystal plate. Its advantage is: It prohibits bandwidth, operating temperature to be high ‘ Reachable 600 Heat good stability, on-state resistance are small, thermal conductivity is good, leakage current minima, PN junction are tall in withstand voltage, help to produce high temperature resistant high-frequency big power semiconductor switching element.

Has already produced 40 mm SiC crystal plate now, already there were 30 mm SiC crystal plates that went on the market in 1990, in electric electron technology, begin to replace Si device with SiC device. For example SiC the intersection of Schottky and diode have goods come out already, quota 300V, 600V, 1200V/20A, reverse recovery time approaches zero, the reverse current of SiC Schottky diode of under 175 is nearly constant.

According to 2004 4th report of magazine of ” electric electron “, have already produced batch SiC device sample, such as SiC power MOSFET, the quota is: 750V/15mA, RDC on =66m; Developed to pressure tight Damien 1400V, on-state SiC power MOSFET with resistance of 311min 1998. Other the intersection of SiC and triode thyristor and for example, 950V/16A is on-state to pigeonhole, lower to 3.67V; Develop pressure tight the intersection of Damien and 790V 1999, on-state to pigeonhole, lower to 1.5V, SiC IGBT with current density of 75A/cm2.

Can predict, the carborundum will most possibly become and employ the material of the successful new power semiconductor in the 21st century.