SKHI24_08

SKHI 24 (R) ... Absolute Maximum Ratings Symbol Conditions Values Units SEMIDRIVERTM Hybrid Dual IGBT Driver SKHI 24 (R) Features Characteristics Symbol Conditions min. typ. max. Units Typical Applications 1) 2) This technical information specifies semiconductor devices but promises no characteristics. No warranty or guarantee expressed or implied is made regarding delivery, performance or suitability. 1 10-06-2008 MHW © by SEMIKRON SKHI 24 ... External Components Component RCE Function Reference voltage for VCE-monitoring 10 ⋅ R CE ( k Ω ) V CEstat ( V ) = ----------------------------------- – 1,4 10 + R CE ( k Ω ) with RVCE = 1kΩ (1700V IGBT): 10 ⋅ RCE ( k Ω ) V CEstat ( V ) = ----------------------------------- – 1,8 10 + R CE ( k Ω ) (1) Recommended Value 10kΩ < RCE < 100kΩ 18kΩ for SKM XX 123 (1200V) 36kΩ for SKM XX 173 (1700V) (1.1) CCE < 2,7nF (2) 0,33nF for SKM XX 123 (1200V) 0,47nF for SKM XX 173 (1700V) 0,5µs < tmin < 10µs (3) CCE Inhibit time for VCE - monitoring 15 – V CEstat ( V ) t min = τ CE ⋅ ln --------------------------------------10 – V CEstat ( V ) 10 ⋅ R CE ( k Ω ) τ CE ( µ s ) = CCE ( nF ) ⋅ ----------------------------------10 + R CE ( k Ω ) RVCE RERROR Collector series resistance for 1700V IGBT-operation Pull-up resistance at error output U Pull – Up ----------------------- < 15mA RERROR 1kΩ / 0,4W 1kΩ < RERROR < 10kΩ RGON RGOFF 3) 4) Turn-on speed of the IGBT 3) Turn-off speed of the IGBT 4) RGON > 1,5Ω RGOFF > 1,5Ω Higher resistance reduces free-wheeling diode peak recovery current, increases IGBT turn-on time. Higher resistance reduces turn-off peak voltage, increases turn-off time and turn-off power dissipation 1916 Driver Electronic – PCB Drivers 10-06-2008 © by SEMIKRON SKHI 24 ... PIN array Fig. 6 shows the pin arrays. The input side (primary side) comprises 10 inputs, forming the interface to the control circuit (see fig.1). The output side (secondary side) of the hybrid driver shows two symmetrical groups of pins with 5 outputs, each forming the interface to the power module. All pins are designed for a grid of 2,54 mm in two rows. Primary side PIN array PIN No. Designation P1 P2 P3 P4, P5, P6, P7 P8 P9, P10 P13 P14 Shield VIN2 VIN1 free /ERROR GND/0V TDT1 TDT2 Explanation internally connected to GND switching signal input 2 (BOTTOM switch); positive 5V logic switching signal input 1 (TOP switch); positive 5V logic not wired error output, low = error; open collector output; max 30V / 15mA ground + 15V ± 4% voltage supply signal input for digital adjustment of locking time; to be switched by bridge to GND signal input for digital adjustment of locking time; to be switched by bridge to GND signal input for inhibiting locking function; to be connected by bridge to GND not wired P11, P12 VS P15 SELECT P16, P17, P18, P19, free P20 ATTENTION: The contactor tracks of the digital input signals P13/ P14/ P15 must not be longer than 20 mm to avoid interferences, if no bridges are connected. Secondary side PIN array PIN No. Designation Explanation ST1 ST2 ST3 ST4 ST9 SB1 SB2 SB3 SB4 SB9 GOFF1 GON1 E1 CCE1 VCE1 GOFF2 GON2 E2 CCE2 VCE2 gate 1 ROFF output (TOP switch) gate 1 RON output (TOP switch) emitter output IGBT 1 (TOP switch) reference voltage adjustment with RCE and CCE (TOP switch) collector output IGBT 1 (TOP switch) gate 2 ROFF output (BOTTOM switch) gate 2 RON output (BOTTOM switch) emitter output IGBT 2 (BOTTOM switch) reference voltage adjustment with RCE and CCE (BOTTOM switch) collector output IGBT 2 (BOTTOM switch) ATTENTION: The connector leads to the power module should be as short as possible. © by SEMIKRON 10-06-2008 Driver Electronic – PCB Drivers 1917 Fig. 1 Block diagram of SKHI 24 * When SKHI 24 is driving 1700V IGBTs, a 1kΩ / 0,4W RVCE-resistor must be connected in series to the VCE-input. ** The VCE-terminal is to be connected to the IGBT collector C. If the VCE-monitoring is not used, connect ST3 to ST9 or SB3 to SB9 respectively. 1-7 Connections to SEMITRANS GB-module 1918 Driver Electronic – PCB Drivers 10-06-2008 © by SEMIKRON SKHI 24 ... SKHI 24 ... SEMIDRIVERTM SKHI 24 Hybrid dual drivers The driver generation SKHI 24 is supplementing the SKHI 21/22 and is suitable for all available medium and high power range IGBT and MOSFETs. It can be said that the SKHI 24 is a function-compatible further developed SKHI 22B. It is recommended to use the SKHI 24 for any new design. General description The new driver generation SKHI 22A/B, SKHI 21A and also SKHI 24 are hybrid components which may directly be mounted to the PCB. All devices necessary for driving, voltage supply, error monitoring and potential separation are integrated in the driver. In order to adapt the driver to the used power module, only very few additional wiring will be necessary. The forward voltage of the IGBT is detected by an integrated short-circuit protection, which will turn off the module when a certain threshold is exceeded. In case of short-circuit or too low supply voltage the integrated error memory is set and an error signal is generated. The driver is connected to a controlled + 15 V-supply voltage. The input signal level is 0/5 V. P15 ; SELECT open / 5V open / 5V open / 5V open / 5V GND P13 ; TDT1 GND GND open / 5V open / 5V X P14 ; TDT2 GND open / 5V GND open / 5V X interlock time tTD /µs 1,3 2,3 3,3 4,3 no interlock Fig. 2 SKHI 24 - Selection of interlock-times: "High"-level can be achieved by no connection or connecting to 5 V. Short pulse suppression The integrated short pulse suppression avoids very short switching pulses at the power semiconductor caused by high-frequency interference pulses at the driver input signals. Switching pulses shorter than 500ns are suppressed and not transmitted to the IGBT. Power supply monitoring (VS) A controlled 15 V-supply voltage is applied to the driver. If it falls below 13 V, an error is monitored and the error output signal switches to low level. Error monitoring and error memory The error memory is set in case of under-voltage or short-circuit of the IGBTs. In case of short-circuit, an error signal is transmitted by the VCE-input via the pulse transformers to the error memory. The error memory will lock all switching pulses to the IGBTs and trigger the error output (P8) of the driver. The error output consists of an open collector transistor, which directs the signal to earth in case of error. SEMIKRON recommends the user to provide for a pull-up resistor directly connected to the error evaluation board and to adapt the error level to the desired signal voltage this way. The open collector transistor may be connected to max. 30 V / 15 mA. If several SKHI 24 are used in one device, the error terminals may also be paralleled. The error memory may only be reset, if no error is pending and both cycle signal inputs are set to low for > 12 µs at the same time. Pulse transformer set The transformer set consists of two pulse transformers. One of them is used bidirectional for turn-on and turn-off signals of the IGBT and the error feedback between primary and secondary side, the other one for the DC/ DC-converter. The DC/DC-converter serves as potential-separation and power supply for the two secondary sides of the driver. The isolation voltage is 4000 VAC . The secondary side consists of two sym-metrical driver switches integrating the following components: Supply voltage The voltage supply consists of a rectifier, a capacitor, a voltage controller for – 8 V and + 15 V and a + 10 V reference voltage. Driver Electronic – PCB Drivers 1919 Technical explanations1 Description of the circuit block diagram and the functions of the driver The block diagram (fig.1) shows the inputs of the driver (primary side) on the left side and the outputs (secondary side) on the right. The following functions are allocated to the primary side: Input-Schmitt-trigger, positive logic (input high = IGBT on). It is also possible to drive the circuit input with 15 V logic, but a 6.8 kΩ resistor has to be connected in series with the input pin (and the internal 100 Ω resistor). Interlock circuit and deadtime generation of the IGBT If one IGBT is turned on, the other IGBT of a halfbridge cannot be switched. Additionally, a digitally adjustable interlocking time is generated by the driver (see fig. 2), which has to be longer than the turn-off delay time of the IGBT. This is to avoid that one IGBT is turned on before the other one is not completely discharged. This protection-function may be neutralized by switching the select input (pin15) (see fig. 2). fig. 2 documents possible interlock-times. „High“ value can be achieved with no connection and connection to 5 V as well. 1. The following descriptions apply to the use of the hybrid driver for IGBTs as well as for power MOSFETs. For the reason of shortness, only IGBTs will be mentioned in the following. The designations „collector“ and „emitter“ will refer to IGBTs, whereas for the MOSFETs „drain“ and „source“ are to be read instead. © by SEMIKRON 10-06-2008 SKHI 24 ... Gate driver The output transistors of the power drivers are MOSFETs. The sources of the MOSFETs are separately connected to external terminals in order to provide setting of the turn-on and turn-off speed by the external resistors RON and ROFF. Do not connect the terminals ST1 with ST2 and SB1 with SB2, respectively. The IGBT is turned on by the driver at +15V by RON and turned off at – 8 V by ROFF. RON and ROFF may not chosen below 1,5 Ω. In order to ensure locking of the IGBT even when the driver supply voltage is turned off, a 22 kΩ-resistor versus the emitter output (E) has been integrated at output GOFF. VCE-monitoring The VCE-monitoring controls the collector-emitter voltage VCE of the IGBT during its on-state. VCE is internally limited to 10 V. If the reference voltage VCEref is exceeded, the IGBT will be switched off and an error is indicated. The reference voltage VCEref may dynamically be adapted to the IGBTs switching behaviour. Immediately after turn-on of the IGBT, a higher value is effective than in the steady state. This value will, however, be reset, when the IGBT is turned off. VCEstat is the steady-state value of VCEref and is adjusted to the required maximum value for each IGBT by an external resistor RCE to be connected between the terminals CCE (ST4/SB4) and E (ST3/SB3). It may not exceed 10 V. The time constant for the delay of VCEref may be increased by an external capacitor CCE, which is connected in parallel to RCE. It controls the time tmin which passes after turn-on of the IGBT before the VCE-monitoring is activated. This makes possible any adaptation to the switching behavior of any of the IGBTs. After tmin has passed, the VCE-monitoring will be triggered as soon as VCE > VCEref and will turn off the IGBT. Dimensioning of RCE and CCE can be done in three steps: 1. Calculate the maximum forward voltage from the datasheet of the used IGBT and determine VCEstat. 2. Calculate approximate value of RCE according to equation (1) or (1.1) from VCEstat or determine RCE by using fig. 3. 3. Determine tmin and calculate CCE according to equations (2) and (3). Typical values are for 1200V IGBT: VCEstat = 5 V; tmin = 1,45 µs, RCE = 18 kΩ, CCE = 330 pF for 1700V IGBT:VCEstat = 6 V; tmin = 3 µs, RCE = 36 kΩ, CCE = 470 pF Adaptation to 1700 V IGBT When using 1700 V IGBTs it is necessary to connect a 1 kΩ / 0,4 W adaptation resistor between the VCE-terminal (ST9/ SB9) and the respective collector. Adaptation to error signal level An open collector transistor is used as error terminal, which, in case of error, leads the signal to earth. The signal has to be adapted to the evaluation circuit voltage level by means of an pull-up resistor. The maximum load applied to the transistor shall be 30 V / 15 mA. IGBT switching speed adjustment The IGBT switching speed may be adjusted by the resistors RON and ROFF. By increasing RON the turn-on speed will decrease. The reverse peak current of the free-wheeling diode will diminish. SEMIKRON recommends to adjust RON to a level that will keep the turn-on delay time td(on) of the IGBT < 1 µs. By increasing ROFF the turn-off speed of the IGBT will decrease. The inductive peak over voltage during turn-off will diminish. The minimum gate resistor value for ROFF and RON is 1,5 Ω. Typical values for RON and ROFF recommended by SEMIKRON are given in fig. 4. Interlock time adjustment Fig. 2 shows the possible interlocking times between output1 and output2. Interlocking times are adjusted by connecting the terminals TDT1 (P13), TDT2 (P14) and SELECT (P15) either to earth/ GND (P16) according to the required function or by leaving them open. SK-IGBT-Modul SKM 50GB123D Vcestat without Rvce (1200V application) Vcestat / V mit Rvce = 1 kOhm (1700V application) External components and possible adjustments of the hybrid driver Fig. 1 shows the required external components for adjustment and adaptation to the power module. VCE - monitoring adjustment The external components RCE and CCE are applied for adjusting the steady-state threshold and the short-circuit monitoring dynamic. RCE and CCE are connected in parallel to the terminals CCE (ST4/ SB4) and E (ST3/ SB3) . 8 7 6 Vcestat in V 5 4 3 2 1 0 10 20 30 40 50 60 Rce in kOhm RGon Ω 22 22 15 12 12 10 8,2 6,8 15 RGoff Ω 22 22 15 12 12 10 8,2 6,8 15 CCE pF 330 330 330 330 330 330 330 330 470 RCE kΩ 18 18 18 18 18 18 18 18 36 RVCE kΩ 0 0 0 0 0 0 0 0 1 SKM 75GB123D SKM 100GB123D SKM 145GB123D SKM 150GB123D SKM 200GB123D SKM 300GB123D SKM 400GA123D SKM 75GB173D Fig. 3 VCEstat in dependence of RCE 1920 Driver Electronic – PCB Drivers 10-06-2008 © by SEMIKRON SKHI 24 ... SKM 100GB173D SKM 150GB173D SKM 200GB173D 12 10 8,2 12 10 8,2 470 470 470 36 36 36 1 1 1 switching frequency 60 kHz 50 kHz Fig. 4 Typical values for external components 40 kHz 30 kHz A typical interlocking time value is 3,25 µs (P14 = GND; P13 and P15 open). ATTENTION: If the terminals TDT1, TDT2 and SELECT are not connected, eventually connected track on PC-board may not be longer than 20 mm in order to avoid interference. SEMIKRON recommends to start-up operation using the values recommended by SEMIKRON and to optimize the values gradually according to the IGBT switching behaviour and overvoltage peaks within the specific circuitry. Driver performance and application limits The drivers are designed for application with halfbridges and single modules with a maximum gate charge QGE < 5 µC. The charge necessary to switch the IGBT is mainly depending on the IGBT's chip size, the DC-link voltage and the gate voltage. This correlation is also shown in the corresponding module datasheet curves. It should, however, be considered that the SKHI 24 is turned on at + 15 V and turned off at – 8 V. Therefore, the gate voltage will change by 23 V during each switching cycle. Unfortunately, most datasheets do not indicate negative gate voltages. In order to determine the required charge, the upper leg of the charge curve may be prolonged to + 23 V for an approximately determination of approximate charge per switch. The medium output current of the driver is determined by the switching frequency and the gate charge. For the SKHI 24 the maximum medium output current is IoutAVmax < ± 80 mA. The maximum switching frequency fMAX may be calculated with the following formula, the maximum value however being 50 kHz due to switching losses: 20 kHz 10 kHz 0 kHz 0,0 µC 1,0 µC 2,0 µC 3,0 µC 4,0 µC 5,0 µC 6,0 µC gate charge Fig. 5 Maximum rating for output gate charge per pulse Further application notes The CMOS-inputs of the hybrid driver are extremely sensitive to overvoltage. Voltages higher than VS + 0,3 V or below – 0,3 V may destroy these inputs. Therefore, control signal overvoltages exceeding the above values have to be avoided. Please provide for static discharge protection during handling. As long as the hybrid driver is not completely assembled, the input terminals have to be short-circuited. Persons working with CMOS-devices have to wear a grounded bracelet. Any synthetic floor coverings must not be statically chargeable. Even during transportation the input terminals have to be short-circuited using, for example, conductive rubber. Worktables have to be grounded. The same safety requirements apply to MOSFET- and IGBT-modules! The connecting leads between hybrid driver and the power module should be as short as possible, the driver leads should be twisted. Any parasitic inductances within the DC-link have to be minimized. Overvoltages may be absorbed by C- or RCD-snubbers between the main terminals for PLUS and MINUS of the power module. When first operating a newly developed circuit, SEMIKRON recommends to apply low collector voltage and load current in the beginning and to increase these values gradually, observing the turn-off behaviour of the free-wheeling diode and the turn-off voltage spikes generated accross the IGBT. An oscillographic control will be necessary. In addition to that the case temperature of the module has to be monitored. When the circuit works correctly under rated operation conditions, short-circuit testing may be done, starting again with low collector voltage. It is important to feed any errors back to the control circuit and to switch off the device immediately in such events. Repeated turn-on of the IGBT into a short circuit with a high frequency may destroy the device. Driver Electronic – PCB Drivers 1921 8 ⋅ 10 f MAX ( kHz ) = ---------------------Q GE ( nC ) © by SEMIKRON 10-06-2008 4 SKHI 24 ... Mechanical fixing on PCB Px 1 Bottom View 9 1 9 Fig. 6 Dimensional drawing and PIN array View: bottom side L x B x H: 113,8 x 56,7 x 20 [mm] grid of connector pins; gaps of connector pins: RM 2,54 mm Pin dimensions: 0,64 mm x 0,64 mm; Length 3,2 mm Max. Isolation Distance between two switches Fig. 7 Dimensions in [mm] for solder pads (as a proposal for a design) and solder pad gaps (partial drawing) with maximum distance between two switches Mounting Hints The temperature of the solder must not exceed 265°C , and solder time must not exceed 4 seconds. The ambient temperature must not exceed the specified maximum storage temperature of the driver. The driver is not suited for hot air reflow or infrared reflow soldering processes. The driver has two drill holes ( inner diameter: 1,8mm ) for fixing the driver on PCB with self tapping screws 30x8 (e.g. EJOT PT). The maximum immersion depth of the screws may not exceed 9 mm. The details of screw head design can be chosen by the user. All electrical and mechanical parameters should be validated by user´s technical experts for each application. This technical information specifies devices but promises no characteristics. No warranty or guarantee expressed or implied is made regarding delivery, performance or suitability. 1922 Driver Electronic – PCB Drivers 10-06-2008 © by SEMIKRON