51 Research and Design, Electronic Engineers website - Embedded Systems, MCU, DSP, EDA, Test and Measurement, Components, Communications, Power, Microelectronics, Semiconductors

Abstract: SKHI22A/B is one kind of new IGBT/MOSFET actuation module which German west gate Kang (SEMIKRON) the company promotes. The article introduced the SKHI22A/B primary structure characteristic and the function, have given its concrete application electric circuit.

    Key word: IGBT; Actuation module; SKHI22A/B

1 outline

The SKHI series actuation module is one kind of new IGBT/MOSFET actuation module which German west gate Kang (SEMIKRON) the company promotes. The SKHI series actuation module mainly has the following characteristic:

* only needs the 15V power source power supply which cannot isolate

* the anti-dV/dt ability may achieve 75kV/μs

* between the control circuit and the IGBT main circuit’s isolation voltage may achieve 4kV

    * the output summit current may achieve 30A

* the identical bridge arm high and low switching valve driving signal has the interlock function, may prevent two switching valve’s penetration breakovers

* the dead time, the VCE monitoring, RGON/OFF may adjust separately, thus may carry on the optimization to the different user’s special demand

* may output the error signal to inform the control system

* has the overflow, the undervoltage protection function.

Below mainly take SKHI22A as an example, carries on the introduction to the SKHI series actuation module.

2 internal structures and principle

SKHI22A/B pin function arrangement like table 1 arranges in order. Shown in Figure 1 is the SKHI series driver’s internal circuit schematic diagram.

Table 1 SKHI22A pin function

2.1 SKHI22A/B pulse shaping electric circuits

In the SKHI pulse shaping electric circuit’s function is after controlling IBGT the signal impulse input, with the short pulse suppression circuit to the pulse width is smaller than the 500ns gate pulse carries on suppresses, enables it to transmit IGBT, like this may effective the voltage peak which suppresses the electromagnetic interference to cause harm triggering to the switching valve, thus enhancement driving circuit’s antijamming ability. Moreover, the module may also carry on (pulse which to the input trigger pulse the reshaping e.g. the commonly used SG3525 chip produces in rise along often to have voltage peak, moreover when pulse height level sometimes level will have fluctuation), moreover after undergoing the SKHI reshaping output, profile already very standard, can thus carry on the control reliably to IGBT.

2.2 SKHI22A/B pulse interlock electric circuits

The pulse interlock electric circuit’s interlock time the height level which by external connection postTDT1, TDT2 and SECELT meets decided. Simultaneously may carry on the digital adjustment by these three posts (SKHI22A only then TDT2). This kind of design may cause the different shutter speed the switch component’s interlock time to be bigger than IGBT the turn-off delay time, thus avoids passing through the breakover.

2.3 SKHI22A/B undervoltage protection circuits

The module internal undervoltage protection circuit’s function is when the supply voltage is lower than 13V, pulls lowly the mistake out-port’s level, outputs the error signal.

The above three part of control circuit is integrated in together ASIC, composes the electric circuit with the general discrete component to compare, like this might big enhancement control circuit’s antijamming ability, simultaneously the reliability also have the enhancement. Moreover, the SKHI series component primary (control section) and secondary (main circuit part) between may also realize the isolation through the transformer.

2.4 SKHI22A/B driver’s output stage

SKHI actuates component’s output stage to use the MOSFET transistor supplementary electric circuit’s form to reduce the actuation source the interface resistance, simultaneously may accelerate IG-BT the shutdown process. Shown in Figure 2 is its output stage electric circuit. In the chart, the MOSFET source carries on the connection separately with the exterior post, like this then through RON which and ROFF serially connects separately adjusts IGBT the clear and the shutdown speed; The internal integrated potential source may enhance the module the reliability; Through the adjustment supply voltage may, in does not reduce VGE in the situation to provide at full capacity output pulse, because thus prevents IGBT to withdraw saturated damages.

2.5 SKHI22A/B short circuit protections

The SKHI module use “the time delay searches the current protection” the method 熗 ü to examine IGBT to pass condition the pressure drop change to realize IGBT the current protection. When the electric circuit presents the short circuit, the error symbol will transmit the mistake controller from the VCE input and through the pulse transformer, will block possesses and triggers the error symbol end to the IGBT pulse (P10). This module examines the VCE voltage signal through the adjustment the time delay to be possible to avoid short-circuiting wrongly the signal; Its interior has the breakdown default memory function, may prevent the redundant high current pulse to switching valve’s damage, after passing through several redundant high pulses, may the permanent suppressor pulse output. In addition, it also simultaneously has the error signal output, may inform the master control board to make the corresponding movement.

2.6 SKHI22A/B voltage isolation

The use belt coating’s ring-like ferrites transformer may cause between the input and the output stage isolation voltage achieves 4kV. This is uses the light pair to make the isolation actuation component not to be able to achieve. The use pulse transformer replaces the light pair in original vice-side between to be possible to prevent very high dV/dt (to be possible to achieve 75kV/μs).

2.7 SKHI22A/B accessory power supplies

Because the SKHI module interior has the belt insulating transformer’s DC/DC converter, thus may save the exterior transformer and may cause the design layout to be more compact; Has in the accessory power supply primary side owes the voltage monitoring circuit, like this may guarantee that IGBT has a security reliable and can provide the enough power the gate extremely driving circuit; Each IGBT uses mutually the independent power source. Therefore, between its power source’s coupling capacity is very small, thus sharpened the switching signal antijamming ability.

3 using electric circuit

SKHI22A/B application electric circuit as shown in Figure 3. In the chart, in-PUT 煟 abundant Greece School 牶 stops Sang Weixiao the Greece to wink abundant 煟 gathers together hopes abundant Greece to stop 牱 the straight kite identical bridge arm top and bottom switching valve’s trigger pulse; When base pin TDT2 meets high level 15V, the dead time for 4.25μs, when meets low level GND, dead time for 3.25μs. ERROR base pin for error signal output, when the module examines the electric circuit to have phenomena and so on overflow, undervoltage and carry on the protection, this base pin level will be pulled lowers informs the master control board.

Base pin S15, S6 external connection RCE and time CCE 熡 broom corn millet interrogation gu annotation long commonplace class protection pressure drop. Regarding 1200V IGBT, chooses RCE is generally 18kΩ, CCE is 300pF, this time the tube pressure drop threshold is 5V. Base pin S14, S7 external connection IGBT electronics grid breakover resistance RON, this resistance should generally when 3~22 OMEGA, the practical application, this resistance gives off heat is quite serious, therefore suggested that uses 2W the resistance. Base pin S13, S8 external connection IGBT electronics grid breakover resistance ROFF, its application method and RON are the same. Base pin S20, S1 connect separately examine the top and bottom switching valve’s drain electrode. Usually regarding 1700V IGBT, should serially connect 1kΩ/0.4W the resistance.