IXDN430 / IXDI430 / IXDD430 / IXDS430 30 Amp Low-Side Ultrafast MOSFET / IGBT Driver Features General Description * Built using the advantages and compatibility of CMOS and IXYS HDMOSTM processes * Latch-Up Protected * High Peak Output Current: 30A Peak * Wide Operating Range: 8.5V to 35V * Under Voltage Lockout Protection * Ability to Disable Output under Faults * High Capacitive Load Drive Capability: 5600 pF in <25ns * Matched Rise And Fall Times * Low Propagation Delay Time * Low Output Impedance * Low Supply Current The IXDN430/IXDI430/IXDD430/IXDS430 are high speed high current gate drivers specifically designed to drive MOSFETs and IGBTs to their minimum switching time and maximum practical frequency limits. The IXD_430 can source and sink 30A of peak current while producing voltage rise and fall times of less than 30ns. The input of the drivers are compatible with TTL or CMOS and are fully immune to latch up over the entire operating range. Designed with small internal delays, cross conduction/current shoot-through is virtually eliminated in all configurations. Their features and wide safety margin in operating voltage and power make the drivers unmatched in performance and value. Applications * Driving MOSFETs and IGBTs * Motor Controls * Line Drivers * Pulse Generators * Local Power ON / OFF Switch * Switch Mode Power Supplies (SMPS) * DC to DC Converters * Pulse Transformer Driver * Limiting di/dt Under Short Circuit * Class D Switching Amplifiers The IXD_430 incorporates a unique ability to disable the output under fault conditions. The standard undervoltage lockout voltages are 11.75V for the IXD_430 parts and 8.5V for the IXD_430M parts. ULVO can be set to either level in the IXDS430 with the UNSEL input line. When a logical low is forced into the Enable inputs, both final output stage MOSFETs (NMOS and PMOS) are turned off. As a result, the output of the IXDD430 enters a tristate mode and enables a Soft Turn-Off of the MOSFET when a short circuit is detected. This helps prevent damage that could occur to the MOSFET if it were to be switched off abruptly due to a dv/dt over-voltage transient. The IXDN430 is configured as a noninverting gate driver, and the IXDI430 is an inverting gate driver. The IXDS430 can be configured either as a noninverting or inverting driver. The IXD_430 are available in the standard 28-pin SIOC (SI-CT), 5-pin TO-220 (CI), and in the TO-263 (YI) surface mount packages. CT or 'Cool Tab' for the 28-pin SOIC package refers to the backside metal heatsink tab. Ordering Information P a rt N u m b e r IX D D 4 3 0 Y I IX D D 4 3 0 M Y I IX D D 4 3 0 C I IX D D 4 3 0 M C I IX D I4 3 0 Y I IX D I4 3 0 M Y I IX D I4 3 0 C I IX D I4 3 0 M C I IX D N 4 3 0 Y I IX D N 4 3 0 M Y I IX D N 4 3 0 C I IX D N 4 3 0 M C I IX D S 4 3 0 S I P ackage T ype Tem p. R ange C o n fig u ra tio n -5 5 C to + 1 2 5 N o n In v e rtin g w ith E n a b le -5 5 C to + 1 2 5 In v e rtin g -5 5 C to + 1 2 5 N o n In v e rtin g 5 -p in T O -2 6 3 5 -p in T O -2 2 0 5 -p in T O -2 6 3 5 -p in T O -2 2 0 5 -p in T O -2 6 3 5 -p in T O -2 2 0 2 8 -p in S O IC -5 5 C to + 1 2 5 In v e rtin g / N o n In v e rtin g w ith E n a b le and UV SEL Copyright (c) IXYS CORPORATION 2005 U n d e r v o lta g e L o c k -o u t 1 1 .7 5 V 8 .5 V 1 1 .7 5 V 8 .5 V 1 1 .7 5 V 8 .5 V 1 1 .7 5 V 8 .5 V 1 1 .7 5 V 8 .5 V 1 1 .7 5 V 8 .5 V 1 1 .7 5 V or 8 .5 V DS99045C(04/04) First Release IXDN430 / IXDI430 / IXDD430 / IXDS430 Figure 1A - IXDD430 (Non Inverting With Enable) Diagram Vcc Vcc 400k 1K IN OUT EN UVCC GND GND Figure 1B - IXDN430 (Non-Inverting) Diagram Vcc Vcc 1K IN OUT UVCC GND GND Figure 1C - IXDI430 (Inverting) Diagram Vcc Vcc 1K IN OUT UVCC GND GND Figure 1D - IXDS430 (Inverting and Non Inverting with Enable) Diagram Vcc IN Vcc OUT P 1K 400K OUT N EN 400K INV UVSEL UVCC GND GND Notes: 1. Out P and Out N are connected together in the 5 lead TO-220 and TO-263 packages; 2. IXDS430: Undervoltage lock-out is set by UVSEL. UVSEL = Vcc, UVLO = 8.5V, UVSEL = OPEN, UVLO = 11.75V. 2 IXDN430 / IXDI430 / IXDD430 / IXDS430 Absolute Maximum Ratings (Note 1) Operating Ratings Parameter Value P a ra m e te r Supply Voltage All Other Pins 40 V -0.3 V to VCC + 0.3 V M a xim um Junction T em perature Power Dissipation, TAMBIENT 25 oC TO220 (CI), TO263 (YI) Derating Factors (to Ambient) TO220 (CI), TO263 (YI) 2W Storage Temperature 0.016W/oC -65 oC to 150 oC Lead Temperature (10 sec) 300 oC V a lu e 150 o C -55 o C to 125 o C T herm al Im pedance T O 220 (C I), TO 263 (Y I) JC (Ju nction T o C ase) 0.95 o C /W JA (Ju nction T o A m bien t) 62.5 o C /W O pera ting T em perature R ange T herm al Im pedance 28 pin S O IC w ith H eat S lug (S I) JC (Ju nction T o C ase) 3 o C /W Electrical Characteristics Unless otherwise noted, TA = 25 oC, 8.5V VCC 35V . All voltage measurements with respect to GND. IXDD430 configured as described in Test Conditions. S ym b o l P a r a m e te r T e s t C o n d itio n s M in V IH H ig h in p u t v o lta g e 0 V V IN V C C , 8 .5 V V IN 1 8 V 3 .5 V IL L o w in p u t v o lta g e 0 V V IN V C C , 8 .5 V V IN 1 8 V V IN In p u t v o lta g e r a n g e I IN In p u t c u rre n t 0 V V IN V C C V OH H ig h o u tp u t v o lta g e V OL L o w o u tp u t v o lta g e R OH O u tp u t re s is ta n c e @ O u tp u t h ig h O u tp u t re s is ta n c e @ O u tp u t L o w P e a k o u tp u t c u rre n t VCC = 18V V EN C o n tin u o u s o u tp u t c u rre n t E n a b le v o lta g e ra n g e L im ite d b y p a c k a g e p o w e r d is s ip a tio n IX D D 4 3 0 O n ly V ENH H ig h E n In p u t V o lta g e IX D D 4 3 0 O n ly V ENL L o w E n In p u t V o lta g e IX D D 4 3 0 O n ly R EN E N In p u t R e s is ta n c e IX D S 4 3 0 O n ly R OL IP E A K ID C T yp M ax U n its V 0 .8 V -5 V C C + 0 .3 V -1 0 10 A V C C - 0 .0 2 5 V 0 .0 2 5 V 0 .3 0 .4 VCC = 18V 0 .2 0 .3 VCC = 18V 30 - 0 .3 A 8 A V c c + 0 .3 V 2 /3 V c c V 1 /3 V c c 400 V K ohm V IN V IN V V o lta g e R a n g e IX D S 4 3 0 O n ly - 0 .3 V IN V H H ig h IN V In p u t V o lta g e IX D S 4 3 0 O n ly 2 /3 V c c V IN V L L o w IN V In p u t V o lta g e IX D S 4 3 0 O n ly R IN V IN V In p u t R e s is ta n c e IX D S 4 3 0 O n ly tR R is e tim e C L= 5 6 0 0 p F V c c = 1 8 V 18 20 ns tF F a ll tim e C L= 5 6 0 0 p F V c c = 1 8 V 16 18 ns tO N D L Y C L= 5 6 0 0 p F V c c = 1 8 V 41 45 ns C L= 5 6 0 0 p F V c c = 1 8 V 35 39 ns IX D D 4 3 0 O n ly , V c c = 1 8 V 47 ns IX D D 4 3 0 O n ly , V c c = 1 8 V 120 ns V CC O n -tim e p ro p a g a tio n d e la y O ff-tim e p ro p a g a tio n d e la y E n a b le to o u tp u t h ig h d e la y tim e D is a b le to o u tp u t lo w d e la y tim e P o w e r s u p p ly v o lta g e 18 35 V IC C P o w e r s u p p ly c u rre n t V IN = 3 .5 V V IN = 0 V V IN = + V C C 1 0 3 10 10 mA A A 8 .5 1 1 .7 5 9 .5 1 3 .0 V V tO FF D L Y tE N O H tD O L D V c c + 0 .3 V 1 /3 V c c 400 8 .5 U VLO IX D _ 4 3 0 M ; IX D S 4 3 0 : U V S E L = V C C (M O S F E T ) IX D _ 4 3 0 ; IX D S 4 3 0 : U V S E L = O P E N (IG B T ) Specifications Subject To Change Without Notice 7 .5 1 0 .5 V V K ohm Note 1: Operating the device beyond parameters with listed "absolute maximum ratings" may cause permanent damage to the device. Typical values indicate conditions for which the device is intended to be functional, but do not guarantee specific performance limits. The guaranteed specifications apply only for the test conditions listed. Exposure to absolute maximum rated conditions for extended periods may affect device reliability. 3 IXDN430 / IXDI430 / IXDD430 / IXDS430 Electrical Characteristics Unless otherwise noted, temperature over -55 oC to +125 oC, 4.5 VCC 35V . All voltage measurements with respect to GND. IXDD430 configured as described in Test Conditions. Symbol Parameter Test Conditions Min VIH High input voltage 8.5 Vcc 18V 3.5 VIL Low input voltage 8.5 Vcc 18V VIN Input voltage range ROH tR Output resistance @ Output high Output resistance @ Output Low Rise time tF tONDLY ROL tOFFDLY VCC Typ Max Units V 1.1 V VCC + 0.3 V VCC = 18V 0.46 VCC = 18V 0.4 CL=5600pF Vcc=18V 20 ns Fall time CL=5600pF Vcc=18V 18 ns On-time propagation delay Off-time propagation delay Power supply voltage CL=5600pF Vcc=18V 58 ns CL=5600pF Vcc=18V 51 ns 35 V -5 8.5 18 5-lead TO-220 Outline (IXD_430CI, IXD_430MCI) 5-lead TO-263 Outline (IXD_430YI, IXD_430MYI) 28-pin SOIC Outline (IXD_430SI) NOTE: Mounting tabs, solder tabs, or heat sink metalization on all packages are connected to ground. 4 IXDN430 / IXDI430 / IXDD430 / IXDS430 Pin Configurations Vcc 1 28 Vcc Vcc 2 27 Vcc Vcc 3 26 Vcc Vcc 4 25 Vcc N/C 5 28 Pin SOIC 24 OUT P (SI-CT) 23 OUT P UVSEL 6 1 2 N/C 7 22 OUT P IN 8 21 OUT N 3 4 5 EN 9 20 OUT N INV 10 19 OUT N GND 11 18 GND GND 12 17 GND GND 13 16 GND GND 14 15 GND Vcc OUT GND IN EN * TO220 (CI) TO263 (YI) Pin Description SYMBOL FUNCTION VCC Supply Voltage IN Input EN * Enable INV Invert OUT P OUT N Output GND Ground UVSEL Select Under Voltage Level DESCRIPTION Positive power-supply voltage input. This pin provides power to the entire chip. The range for this voltage is from 8.5V to 35V. Input signal-TTL or CMOS compatible. The system enable pin. This pin, when driven low, disables the chip, forcing high impedance state to the output (IXDD430 Only). Forcing INV low causes the IXDS430 to become non-inverted, while forcing INV high causes the IXDS430 to become inverted. Respective P and N driver outputs. For application purposes this pin is connected, through a resistor, to Gate of a MOSFET/IGBT. The P and N output pins are connected together in the TO-263 and TO-220 packages. The system ground pin. Internally connected to all circuitry, this pin provides ground reference for the entire chip. This pin should be connected to a low noise analog ground plane for optimum performance. W ith UVSEL connected to Vcc, IXDS430 outputs go low at Vcc < 8.5V; W ith UVSEL open, under voltage level is set at Vcc < 12.5V * This pin is used only on the IXDD430, and is N/C (not connected) on the IXDI430 and IXDN430. CAUTION: These devices are sensitive to electrostatic discharge; follow proper ESD procedures when handling and assembling this component. Figure 2 - Characteristics Test Diagram . . Vcc + C BYPASS/ FILTER Vcc OUT - GND IXDD430 CLOAD IN EN + Vin - 5 IXDN430 / IXDI430 / IXDD430 / IXDS430 Typical Performance Characteristics Fig. 3 Fig. 4 Rise Tim es vs. Supply Voltage Fall Tim es vs. Supply Voltage 30 35 30 25 15000 pF 15000 pF 10000 pF Fall Time (ns) Rise Time (ns) 25 20 5600 pF 15 20 10000 pF 5600 pF 15 10 10 1000 pF 1000 pF 5 5 0 0 10 15 20 25 30 10 35 15 20 Fig. 5 25 30 Fig. 6 Output Rise Times vs. Load Capacitance Output Fall Times vs. Load Capacitance 30 13V 18V 35V 30 25 35V 18V 13V Fall Time (ns) 25 Rise Time (ns) 35 Supply Voltage (V ) Supply Voltage (V) 20 15 20 15 10 10 5 5 1000 3000 5000 7000 9000 11000 13000 0 1000 15000 3000 5000 Load Capacitance (pF) Fig. 7 7000 Rise and Fall Times vs. Temperature CL = 5600 pF, Vcc = 18V Fig. 8 25 11000 13000 15000 Max / Min Input vs. Temperature CL = 5600pF, Vcc = 18V 4 3.5 20 tR Max / Min Input Voltage Time (ns) 9000 Load Capacitance (pF) 15 tF 10 5 Min Input High 3 Max Input Low 2.5 2 1.5 1 0.5 0 0 -60 -10 40 90 140 190 -60 Temperature (C) -10 40 90 Temperature (C) 6 140 190 IXDN430 / IXDI430 / IXDD430 / IXDS430 Fig. 9 Supply Current vs. Load Capacitance Vcc = 13V Fig. 10 1000 300 Supply Current vs. Frequency Vcc = 13V 15000 10000 5600 1000 2 MHz 100 Supply Current (mA) Supply Current (mA) 250 1 MHz 200 150 500 kHz 100 pF pF pF pF 10 1 50 100 kHz 50 kHz 10 kHz 0 1000 10000 0.1 1 100000 10 Load Capacitance (pF) Supply Current vs. Load Capacitance Vcc = 18V Fig. 11 100 1000 Fig. 12 300 Supply Current vs. Frequency Vcc = 18V 15000 pF 10000 pF 5600 pF 1000 pF 1000 2 MHz 1 MHz Supply Current (mA) Supply Current (mA) 250 200 500 kHz 150 100 50 100 10 1 100 kHz 50 kHz 10 kHz 0 1000 10000 0.1 1 100000 10 Fig. 14 Supply Current vs. Load Capacitance Vcc = 25V Fig. 13 100 1000 Supply Current vs. Frequency Vcc = 25V 1000 400 350 15000 pF 10000 pF 5600 pF 1000 pF 1 MHz 300 Supply Current (mA) Supply Current (mA) 2 MHz 10000 Frequency (kHz) Load Capacitance (pF) 250 200 500 kHz 150 100 100 10 1 100 kHz 50 0 1000 10000 Frequency (kHz) 50 kHz 10 kHz 10000 0.1 1 100000 10 100 Frequency (kHz) Load Capacitance (pF) 7 1000 10000 IXDN430 / IXDI430 / IXDD430 / IXDS430 Fig. 15 Supply Current vs. Load Capacitance Vcc = 35V Fig. 16 400 1000 Supply Current vs. Frequency Vcc = 35V 350 15000 pF 10000 pF 5600 pF 1000 pF Supply Current (mA) Supply Current (mA) 1 MHz 300 500 kHz 250 200 150 100 100 kHz 100 10 50 kHz 50 10 kHz 1 0 1000 10000 1 100000 10 Load Capacitance (pF) Fig. 17 50 100 Fig. 18 Propagation Delay vs. Supply Voltage CL = 5600 pF Vin = 15V@1kHz Propagation Delay vs. Input Voltage CL = 5600 pF Vcc = 18V 50 45 tONDLY tONDLY 40 40 Propagation Delay (ns) Propagation Delay (ns) 10000 Frequency (kHz) 45 35 tOFFDLY 30 25 20 15 35 tOFFDLY 30 25 20 15 10 10 5 5 0 0 10 15 20 25 30 5 35 10 Fig. 19 15 20 25 Input Voltage (V) Supply Voltage (V) Fig. 20 Propagation Delay Times vs. Temperature CL = 5600pF, Vcc = 18V Quiescent Supply Current vs. Temperature Vcc = 18V, Vin = 15V@1kHz, CL = 5600pF 0.6 Quiescent Vcc Input Current (mA) 70 60 50 tONDLY Time (ns) 1000 40 tOFFDLY 30 20 10 0 0.5 0.4 0.3 0.2 0.1 0 -60 -10 40 90 140 190 -60 Temperature (C) -10 40 90 Temperature (C) 8 140 190 IXDN430 / IXDI430 / IXDD430 / IXDS430 Fig. 21 High State Output Resistance vs. Supply Voltage Fig. 22 Low State Output Resistance (Ohms) High State Output Resistance (Ohms) Low State Output Resistance vs. Supply Voltage 0.25 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0.2 0.15 0.1 0.05 0 0 10 15 20 25 30 35 40 10 15 20 Supply Voltage (V) Fig. 23 P Channel Output Current vs. Vcc Fig. 24 0 N Channel Output Current (A) P Channel Output Current (A) 30 35 40 N Channel O utput Current vs. Vcc 70 -10 -20 -30 -40 -50 -60 -70 60 50 40 30 20 10 -80 0 10 15 20 25 30 35 40 10 15 20 V cc (V) 25 30 35 40 Vcc (V) Fig. 25 P Channel Output Current vs. Temperature Fig. 26 Vcc = 18V N Channel Output Current vs. Temperature Vcc = 18V 45 40 40 35 N Channel Output Current (A) P Channel Output Current (A) 25 Supply Voltage (V) 30 25 20 15 10 35 30 25 20 15 10 5 5 0 0 -60 -10 40 90 140 -60 190 -10 40 90 Temperature (C) Temperature (C) 9 140 190 IXDN430 / IXDI430 / IXDD430 / IXDS430 Figure 27 - Typical circuit to decrease di/dt during turn-off Figure 28 - IXDD430 Application Test Diagram + Ld 10uH - VB Rd IXDD430 0.1ohm VCC VCCA Rg OUT IN EN + - VCC + - VIN High_Power VMO580-02F 1ohm Rsh 1600ohm GND GND Rs Low_Power 2N7002/PLP Ls R+ 10kohm 20nH One Shot Circuit Rcomp 5kohm NAND CD4011A NOT1 CD4049A NOT2 CD4049A Ccomp 1pF Ros 0 Comp LM339 + V+ V- C+ 100pF + R 1Mohm REF Cos 1pF Q NOT3 CD4049A NOR1 CD4001A EN NOR2 CD4001A SR Flip-Flop 10 S - IXDN430 / IXDI430 / IXDD430 / IXDS430 APPLICATIONS INFORMATION Short Circuit di/dt Limit A short circuit in a high-power MOSFET module such as the VM0580-02F, (580A, 200V), as shown in Figure 27, can cause the current through the module to flow in excess of 1500A for 10s or more prior to self-destruction due to thermal runaway. For this reason, some protection circuitry is needed to turn off the MOSFET module. However, if the module is switched off too fast, there is a danger of voltage transients occuring on the drain due to Ldi/dt, (where L represents total inductance in series with drain). If these voltage transients exceed the MOSFET's voltage rating, this can cause an avalanche breakdown. In this way, the high-power MOSFET module is softly turned off by the IXDD430, preventing its destruction. Supply Bypassing and Grounding Practices, Output Lead inductance When designing a circuit to drive a high speed MOSFET utilizing the IXDD430/IXDI430/IXDN430, it is very important to keep certain design criteria in mind, in order to optimize performance of the driver. Particular attention needs to be paid to Supply Bypassing, Grounding, and minimizing the Output Lead Inductance. The IXDD430 has the unique capability to softly switch off the high-power MOSFET module, significantly reducing these Ldi/dt transients. Say, for example, we are using the IXDD430 to charge a 15nF capacitive load from 0 to 25 volts in 25ns. Thus, the IXDD430 helps to prevent device destruction from both dangers; over-current, and avalanche breakdown due to di/dt induced over-voltage transients. Using the formula: I= C V / t, where V=25V C=15nF & t=25ns we can determine that to charge 15nF to 25 volts in 25ns will take a constant current of 15A. (In reality, the charging current won't be constant, and will peak somewhere around 30A). The IXDD430 is designed to not only provide 30A under normal conditions, but also to allow it's output to go into a high impedance state. This permits the IXDD430 output to control a separate weak pull-down circuit during detected overcurrent shutdown conditions to limit and separately control dVGS/dt gate turnoff. This circuit is shown in Figure 28. SUPPLY BYPASSING In order for our design to turn the load on properly, the IXDD430 must be able to draw this 5A of current from the power supply in the 25ns. This means that there must be very low impedance between the driver and the power supply. The most common method of achieving this low impedance is to bypass the power supply at the driver with a capacitance value that is a magnitude larger than the load capacitance. Usually, this would be achieved by placing two different types of bypassing capacitors, with complementary impedance curves, very close to the driver itself. (These capacitors should be carefully selected, low inductance, low resistance, high-pulse current-service capacitors). Lead lengths may radiate at high frequency due to inductance, so care should be taken to keep the lengths of the leads between these bypass capacitors and the IXDD430 to an absolute minimum. Referring to Figure 28, the protection circuitry should include a comparator, whose positive input is connected to the source of the VM0580-02. A low pass filter should be added to the input of the comparator to eliminate any glitches in voltage caused by the inductance of the wire connecting the source resistor to ground. (Those glitches might cause false triggering of the comparator). The comparator's output should be connected to a SRFF(Set Reset Flip Flop). The flip-flop controls both the Enable signal, and the low power MOSFET gate. Please note that CMOS 4000-series devices operate with a VCC range from 3 to 15 VDC, (with 18 VDC being the maximum allowable limit). GROUNDING In order for the design to turn the load off properly, the IXDD430 must be able to drain this 5A of current into an adequate grounding system. There are three paths for returning current that need to be considered: Path #1 is between the IXDD430 and it's load. Path #2 is between the IXDD430 and it's power supply. Path #3 is between the IXDD430 and whatever logic is driving it. All three of these paths should be as low in resistance and inductance as possible, and thus as short as practical. In addition, every effort should be made to keep these three ground paths distinctly separate. Otherwise, (for instance), the returning ground current from the load may develop a voltage that would have a detrimental effect on the logic line driving the IXDD430. A low power MOSFET, such as the 2N7000, in series with a resistor, will enable the VMO580-02F gate voltage to drop gradually. The resistor should be chosen so that the RC time constant will be 100us, where "C" is the Miller capacitance of the VMO580-02F. For resuming normal operation, a Reset signal is needed at the SRFF's input to enable the IXDD430 again. This Reset can be generated by connecting a One Shot circuit between the IXDD430 Input signal and the SRFF restart input. The One Shot will create a pulse on the rise of the IXDD430 input, and this pulse will reset the SRFF outputs to normal operation. When a short circuit occurs, the voltage drop across the lowvalue, current-sensing resistor, (Rs=0.005 Ohm), connected between the MOSFET Source and ground, increases. This triggers the comparator at a preset level. The SRFF drives a low input into the Enable pin disabling the IXDD430 output. The SRFF also turns on the low power MOSFET, (2N7000). 11 IXDN430 / IXDI430 / IXDD430 / IXDS430 OUTPUT LEAD INDUCTANCE Of equal importance to Supply Bypassing and Grounding are issues related to the Output Lead Inductance. Every effort should be made to keep the leads between the driver and it's load as short and wide as possible. If the driver must be placed farther than 2" from the load, then the output leads should be treated as transmission lines. In this case, a twisted-pair should be considered, and the return line of each twisted pair should be placed as close as possible to the ground pin of the driver, and connect directly to the ground terminal of the load. TTL to High Voltage CMOS Level Translation (IXDD430 Only) The enable (EN) input to the IXDD430 is a high voltage CMOS logic level input where the EN input threshold is 1/2 VCC, and may not be compatible with 5V CMOS or TTL input levels. The IXDD430 EN input was intentionally designed for enhanced noise immunity with the high voltage CMOS logic levels. In a typical gate driver application, VCC =15V and the EN input threshold at 7.5V, a 5V CMOS logical high input applied to this typical IXDD430 application's EN input will be misinterpreted as a logical low, and may cause undesirable or unexpected results. The note below is for optional adaptation of TTL or 5V CMOS levels. A TTL or 5V CMOS logic low, VTTLLOW=~<0.8V, input applied to the Q1 emitter will drive it on. This causes the level translator output, the Q1 collector output to settle to VCESATQ1 + VTTLLOW=<~2V, which is sufficiently low to be correctly interpreted as a high voltage CMOS logic low (<1/3VCC=5V for VCC =15V given in the IXDD430 data sheet.) A TTL high, VTTLHIGH=>~2.4V, or a 5V CMOS high, V5VCMOSHIGH=~>3.5V, applied to the EN input of the circuit in Figure 29 will cause Q1 to be biased off. This results in Q1 collector being pulled up by R3 to VCC=15V, and provides a high voltage CMOS logic high output. The high voltage CMOS logical EN output applied to the IXDD430 EN input will enable it, allowing the gate driver to fully function as an 30 Amp output driver. The total component cost of the circuit in Figure 29 is less than $0.10 if purchased in quantities >1K pieces. It is recommended that the physical placement of the level translator circuit be placed close to the source of the TTL or CMOS logic circuits to maximize noise rejection. The circuit in Figure 29 alleviates this potential logic level misinterpretation by translating a TTL or 5V CMOS logic input to high voltage CMOS logic levels needed by the IXDD430 EN input. From the figure, VCC is the gate driver power supply, typically set between 8V to 20V, and VDD is the logic power supply, typically between 3.3V to 5.5V. Resistors R1 and R2 form a voltage divider network so that the Q1 base is positioned at the midpoint of the expected TTL logic transition levels. Figure 29 - TTL to High Voltage CMOS Level Translator Vcc (From gate driver power supply) (From logic Vdd power supply) R3 10K R1 10K Q1 2N3904 High Voltage CMOS EN output (To IXDD430 EN input) R2 10K 5V CMOS or TTL input EN IXYS Corporation 3540 Bassett St; Santa Clara, CA 95054 Tel: 408-982-0700; Fax: 408-496-0670 www.ixys.com e-mail: sales@ixys.net IXYS Semiconductor GmbH Edisonstrasse15 ; D-68623; Lampertheim Tel: +49-6206-503-0; Fax: +49-6206-503627 e-mail: marcom@ixys.de 12 DS99045A(8/03)