HCPL-3020/HCPL-0302 0.4 Amp Output Current IGBT Gate Drive Optocoupler Data Sheet Description Features The HCPL-3020 and HCPL-0302 consist of a GaAsP LED optically coupled to an integrated circuit with a power output stage. These optocouplers are ideally suited for driving power IGBTs and MOSFETs used in motor control inverter applications. The high operating voltage range of the output stage provides the drive voltages required by gate-controlled devices. The voltage and current supplied by this optocoupler makes it ideally suited for directly driving small or medium power IGBTs. For IGBTs with higher ratings, the HCPL-0314/3140 (0.6 A), HCPL3150 (0.6 A) or HCPL-3120 (2.5 A) gate drive opto-couplers can be used. * 0.4 A maximum peak output current * 0.2 A minimum peak output current * High speed response: 0.7 s maximum propagation delay over temperature range * Ultra high CMR: minimum 10 kV/s at VCM = 1000 V * Bootstrappable supply current: maximum 3 mA * Wide operating temperature range: -40C to 100C * Wide VCC operating range: 10 V to 30 V over temperature range * Available in DIP 8 and SO-8 packages * Safety approvals: UL approval, 3750 VRMS for 1 minute * CSA approval * IEC/EN/DIN EN 60747-5-2 approval VIORM = 630 VPEAK (HCPL-3020), VIORM = 566 VPEAK (HCPL-0302) Functional Diagram N/C 1 8 VCC ANODE 2 7 N/C CATHODE 3 6 VO N/C 4 5 VEE SHIELD Truth Table LED VO OFF LOW ON HIGH Applications * * * * * * * Isolated IGBT/power MOSFET gate drive AC and brushless DC motor drives Industrial inverters Air conditioner Washing machine Induction heater for cooker Switching power supplies (SPS) Note: A 0.1 uF bypass capacitor must be connected between pins VCC and VEE. CAUTION: It is advised that normal static precautions be taken in handling and assembly of this component to prevent damage and /or degradation which may be induced by ESD. Ordering Information Specify part number followed by option number (if desired). Example: HCPL-3020-XXXX No option = Standard DIP package, 50 per tube 300 = Gull Wing Surface Mount Option, 50 per tube 500 = Tape and Reel Packaging Option 060 = IEC/EN/DIN EN 60747-5-2, VIORM = 630 VPEAK XXXE = Lead Free Option HCPL-0302-XXXX No option = Standard SO-8 package, 100 per tube 500 = Tape and Reel Packaging Option 060 = IEC/EN/DIN EN 60747-5-2, VIORM = 566 VPEAK XXXE = Lead Free Option Package Outline Drawings HCPL-3020 Standard DIP Package 7.62 0.25 (0.300 0.010) 9.65 0.25 (0.380 0.010) TYPE NUMBER 8 7 6 5 OPTION CODE* 6.35 0.25 (0.250 0.010) DATE CODE A XXXXZ YYWW 1 1.19 (0.047) MAX. 2 3 4 1.78 (0.070) MAX. 5 TYP. 3.56 0.13 (0.140 0.005) 4.70 (0.185) MAX. 0.51 (0.020) MIN. 2.92 (0.115) MIN. 1.080 0.320 (0.043 0.013) 0.65 (0.025) MAX. 2.54 0.25 (0.100 0.010) + 0.076 - 0.051 + 0.003) (0.010 - 0.002) 0.254 DIMENSIONS IN MILLIMETERS AND (INCHES). * MARKING CODE LETTER FOR OPTION NUMBERS. "V" = OPTION 060 OPTION NUMBERS 300 AND 500 NOT MARKED. NOTE: FLOATING LEAD PROTUSION IS 0.25 mm (10 mils) MAX. HCPL-3020 Gull Wing Surface Mount Option 300 Land Pattern Recommendation 9.65 0.25 (0.380 0.010) 6 7 8 1.016 (0.040) 5 6.350 0.25 (0.250 0.010) 1 3 2 10.9 (0.430) 4 2.0 (0.080) 1.27 (0.050) 9.65 0.25 (0.380 0.010) 1.780 (0.070) MAX. 1.19 (0.047) MAX. 7.62 0.25 (0.300 0.010) 0.20 (0.008) 0.33 (0.013) 3.56 0.13 (0.140 0.005) 1.080 0.320 (0.043 0.013) 0.635 0.25 (0.025 0.010) 0.635 0.130 (0.025 0.005) 2.54 (0.100) BSC DIMENSIONS IN MILLIMETERS (INCHES). LEAD COPLANARITY = 0.10 mm (0.004 INCHES). 12 NOM. NOTE: FLOATING LEAD PROTUSION IS 0.25 mm (10 mils) MAX. HCPL-0302 Small Outline SO-8 Package Land Pattern Recommendation 8 7 6 5 XXX YWW 3.937 0.127 (0.155 0.005) 5.994 0.203 (0.236 0.008) TYPE NUMBER (LAST 3 DIGITS) 7.49 (0.295) DATE CODE PIN ONE 1 2 3 0.406 0.076 (0.016 0.003) 4 1.9 (0.075) 1.270 BSC (0.050) 0.64 (0.025) * 5.080 0.127 (0.200 0.005) 3.175 0.127 (0.125 0.005) * 7 1.524 (0.060) TOTAL PACKAGE LENGTH (INCLUSIVE OF MOLD FLASH) 5.207 0.254 (0.205 0.010) DIMENSIONS IN MILLIMETERS (INCHES). LEAD COPLANARITY = 0.10 mm (0.004 INCHES) MAX. 45 X 0.432 (0.017) 0~7 0.228 0.025 (0.009 0.001) 0.203 0.102 (0.008 0.004) 0.305 MIN. (0.012) NOTE: FLOATING LEAD PROTUSION IS 0.15 mm (6 mils) MAX. Solder Reflow Temperature Profile 300 PREHEATING RATE 3C + 1C/-0.5C/SEC. REFLOW HEATING RATE 2.5C 0.5C/SEC. TEMPERATURE (C) 200 PEAK TEMP. 245C PEAK TEMP. 240C 2.5C 0.5C/SEC. SOLDERING TIME 200C 30 SEC. 160C 150C 140C PEAK TEMP. 230C 30 SEC. 3C + 1C/-0.5C 100 PREHEATING TIME 150C, 90 + 30 SEC. 50 SEC. TIGHT TYPICAL LOOSE 0 0 50 ROOM TEMPERATURE 100 150 TIME (SECONDS) Note: Use of non-chlorine-activated fluxes is highly recommended Recommended Solder Reflow Temperature Profile (Lead free) TEMPERATURE (C) tp Tp 217 C TL Tsmax Tsmin 260 +0/-5 C RAMP-UP 3 C/SEC. MAX. 150 - 200 C ts PREHEAT 60 to 180 SEC. TIME WITHIN 5 C of ACTUAL PEAK TEMPERATURE 20-40 SEC. RAMP-DOWN 6 C/SEC. MAX. tL 60 to 150 SEC. 25 t 25 C to PEAK TIME (SECONDS) NOTES: THE TIME FROM 25 C to PEAK TEMPERATURE = 8 MINUTES MAX. Tsmax = 200 C, Tsmin = 150 C Note: Use of non-chlorine-activated fluxes is highly recommended 200 250 Regulatory Information The HCPL-0302/3020 has been approved by the following organizations: IEC/EN/DIN EN 60747-5-2 Approved under: IEC 60747-5-2:1997 + A1:2002 EN 60747-5-2:2001 + A1:2002 DIN EN 60747-5-2 (VDE 0884 Teil 2):2003-01. (Option 060 only) UL Approval under UL 1577, component recognition program up to VISO = 3750 VRMS. File E55361. CSA Approval under CSA Component Acceptance Notice #5, File CA 88324. IEC/EN/DIN EN 60747-5-2 Insulation Characteristics (HCPL-3020 and HCPL-0302 Option 060) Description Symbol HCPL-3020 HCPL-0302 Unit Installation Classification per DIN VDE 0110/1.89, Table 1 for Rated Mains Voltage 150 Vrms I - IV I - IV for Rated Mains Voltage 300 Vrms I - III I - III for Rated Mains Voltage 600 Vrms I - II Climatic Classification 55/100/21 55/100/21 Pollution Degree (DIN VDE 0110/1.89) 2 2 Maximum Working Insulation Voltage VIORM 630 566 Vpeak VPR 1181 1050 Vpeak VPR 945 840 Vpeak VIOTM 6000 4000 Vpeak Input to Output Test Voltage, Method b [1] VIORM x 1.875 = VPR, 100% Production Test with tm = 1 sec, Partial Discharge < 5 pC Input to Output Test Voltage, Method a [1] VIORM x 1.5 = VPR, Type and Sample Test, tm = 60 sec, Partial Discharge < 5 pC Highest Allowable Overvoltage (Transient Overvoltage tini = 10 sec) Safety-Limiting Values - Maximum Values Allowed in the Event of a Failure. Case Temperature TS 175 150 C Input Current [2] IS, INPUT 230 150 mA Output Power [2] PS, OUTPUT 600 600 mW RS >109 >109 Insulation Resistance at TS, VIO = 500 V 800 OUTPUT POWER - PS, INPUT CURRENT - IS 1. Refer to the optocoupler section of the Isolation and Control Components Designer's Catalog, under Product Safety Regulations section, (IEC/EN/DIN EN 60747-5-2), for a detailed description of Method a and Method b partial discharge test profiles. 2. Refer to the following figure for dependence of PS and IS on ambient temperature. PS (mW) IS (mA) 700 600 500 400 300 200 100 0 0 25 50 75 100 125 150 175 200 TS - CASE TEMPERATURE - C Insulation and Safety Related Specifications Parameter Symbol HCPL-3020 HCPL-0302 Units Conditions Minimum External Air Gap L(101) 7.1 4.9 mm (Clearance) Minimum External Tracking L(102) 7.4 4.8 mm (Creepage) Minimum Internal Plastic Gap 0.08 0.08 mm (Internal Clearance) Tracking Resistance CTI (Comparative Tracking Index) Isolation Group >175 >175 IIIa IIIa Absolute Maximum Ratings Parameter Storage Temperature Operating Temperature Average Input Current Peak Transient Input Current (<1 s pulse width, 300 pps) Reverse Input Voltage "High" Peak Output Current "Low" Peak Output Current Supply Voltage Output Voltage Output Power Dissipation Input Power Dissipation Lead Solder Temperature Solder Reflow Temperature Profile Recommended Operating Conditions Parameter Symbol Power Supply VCC - VEE Input Current (ON) IF(ON) Input Voltage (OFF) VF(OFF) Operating Temperature TA Min. 10 7 -3.0 -40 V Measured from input terminals to output terminals, shortest distance through air. Measured from input terminals to output terminals, shortest distance path along body. Through insulation distance conductor to conductor, usually the straight line distance thickness between the emitter and detector. DIN IEC 112/VDE 0303 Part 1 Material Group (DIN VDE 0110, 1/89, Table 1) Symbol Min. Max. Units Note TS -55 125 C TA -40 100 C IF(AVG) 20 mA 1 IF(TRAN) 1.0 A VR 5 V IOH(PEAK) 0.4 A 2 IOL(PEAK) 0.4 A 2 VCC - VEE -0.5 35 V VO(PEAK) -0.5 VCC V PO 250 mW 3 PI 45 mW 4 260C for 10 sec., 1.6 mm below seating plane See Package Outline Drawings section Max. 30 12 0.8 100 Units Note V mA V C Electrical Specifications (DC) Over recommended operating conditions unless otherwise specified. Parameter Note Symbol Min. Typ. Max. Units Test Conditions Fig. High Level Output Current IOH 0.15 A VO = VCC - 4 5 0.2 0.3 A VO = VCC - 10 2 2 Low Level Output Current IOL 0.15 A VO = VEE + 2.5 5 0.2 0.3 A VO = VEE + 10 4 2 High Level Output Voltage VOH VCC - 4 VCC - 1.8 V IO = -100 mA 1 6, 7 Low Level Output Voltage VOL 0.4 1 V IO = 100 mA 3 High Level Supply Current ICCH 0.7 3 mA IO = 0 mA 5, 6 14 Low Level Supply Current ICCL 1.2 3 mA IO = 0 mA Threshold Input Current Low to High IFLH 6 mA IO = 0 mA, 7, 13 VO > 5 V Threshold Input Voltage High to Low VFHL 0.8 V Input Forward Voltage VF 1.2 1.5 1.8 V IF = 10 mA 14 Temperature Coefficient of Input DVF/DTA -1.6 mV/C Forward Voltage Input Reverse Breakdown Voltage BVR 5 V IR = 10 A Input Capacitance CIN 60 pF f = 1 MHz, VF = 0 V Switching Specifications (AC) Over recommended operating conditions unless otherwise specified. Parameter Symbol Min. Typ. Max. Units Test Conditions Fig. Note Propagation Delay Time to High tPLH 0.1 0.2 0.7 s Rg=75, Cg = 1.5 nF, 8, 9 14 Output Level f = 10 kHz, Duty Cycle = 50%, 10, 11 IF = 7 mA, VCC = 30 V 12, 15 Propagation Delay Time to Low tPHL 0.1 0.2 0.7 s Output Level Propagation Delay Difference PDD -0.5 0.5 s 10 Between Any Two Parts or Channels Rise Time tR 50 ns Fall Time tF 50 ns Output High Level Common Mode |CMH| 10 kV/s TA = 25C, VCM = 1000 V 16 11 Transient Immunity Output Low Level Common Mode |CML| 10 kV/s 16 12 Transient Immunity Package Characteristics Parameter Symbol Input-Output Momentary Withstand Voltage Input-Output Resistance Input-Output Capacitance VISO Min. Typ. Max. 3750 RI-O CI-O 1012 0.6 Units Test Conditions Fig. Note Vrms TA = 25C, RH < 50% 8, 9 pF VI-O = 500 V Freq = 1 MHz 9 -0.5 -1.0 -1.5 -2.0 -2.5 -50 -25 0 25 50 75 TA - TEMPERATURE - C 100 125 0 0.44 VOL - OUTPUT LOW VOLTAGE - V 0 (VOH-VCC) - OUTPUT HIGH VOLTAGE DROP - V (VOH-VCC) - HIGH OUTPUT VOLTAGE DROP - V Notes: 1. Derate linearly above 70C free air temperature at a rate of 0.3 mA/C. 2. Maximum pulse width = 10 s, maximum duty cycle = 0.2%. This value is intended to allow for component tolerances for designs with IO peak minimum = 0.2 A. See Application section for additional details on limiting IOL peak. 3. Derate linearly above 85C, free air temperature at the rate of 4.0 mW/C. 4. Input power dissipation does not require derating. 5. Maximum pulse width = 50 s, maximum duty cycle = 0.5%. 6. In this test, VOH is measured with a DC load current. When driving capacitive load VOH will approach VCC as IOH approaches zero amps. 7. Maximum pulse width = 1 ms, maximum duty cycle = 20%. 8. In accordance with UL 1577, each optocoupler is proof tested by applying an insulation test voltage >4500 Vrms for 1 second (leakage detection current limit II-O < 5 A). This test is performed before 100% production test for partial discharge (method B) shown in the IEC/EN/DIN EN 60747-5-2 Insulation Characteristics Table, if applicable. 9. Device considered a two-terminal device: pins on input side shorted together and pins on output side shorted together. 10. PDD is the difference between tPHL and tPLH between any two parts or channels under the same test conditions. 11. Common mode transient immunity in the high state is the maximum tolerable |dVCM/dt| of the common mode pulse VCM to assure that the output will remain in the high state (i.e. VO > 6.0 V). 12. Common mode transient immunity in a low state is the maximum tolerable |dVCM/dt| of the common mode pulse, VCM, to assure that the output will remain in a low state (i.e. VO < 1.0 V). 13. This load condition approximates the gate load of a 1200 V/20 A IGBT. 14. The power supply current increases when operating frequency and Cg of the driven IGBT increases. -1 -2 -3 -4 0 0.2 IOH - OUTPUT HIGH CURRENT - A Figure 1. VOH vs. temperature. Figure 2. VOH vs. IOH. 0.4 0.43 0.42 0.41 0.40 0.39 -50 -25 0 25 50 75 TA - TEMPERATURE - C Figure 3. VOL vs. temperature. 100 125 3 2 1 0 0.1 0.2 0.3 1.2 1.2 1.0 1.0 0.8 0.6 0.4 ICCL ICCH 0.2 0 -50 0.4 IOL - OUTPUT LOW CURRENT - A 75 100 2.5 2.0 -25 0 25 50 75 100 300 TP - PROPAGATION DELAY - ns 300 200 TPLH TPHL 25 50 75 100 125 200 100 TPLH TPHL 15 20 25 TA - TEMPERATURE - C Figure 10. Propagation delay vs. tempera- 25 30 200 100 0 30 6 9 12 15 18 IF - FORWARD LED CURRENT - mA Figure 9. Propagation delay vs. IF. 400 350 TPLH TPHL 300 250 200 20 300 VCC - SUPPLY VOLTAGE - V 400 15 Figure 6. ICC vs. VCC. 400 0 ICCL ICCH 0.2 400 0 10 125 500 -25 0.4 VCC - SUPPLY VOLTAGE - V Figure 8. Propagation delay vs. VCC. 100 0.6 0 10 125 TP - PROPAGATION DELAY - ns TP - PROPAGATION DELAY - ns IFLH - LOW TO HIGH CURRENT THRESHOLD - mA 3.0 Figure 7. IFLH vs. temperature. TP - PROPAGATION DELAY - ns 50 400 TA - TEMPERATURE - C 25 Figure 5. ICC vs. temperature. 3.5 0 -50 0 0.8 TA - TEMPERATURE - C Figure 4. VOL vs. IOL. 1.5 -50 -25 TP - PROPAGATION DELAY - ns 0 1.4 ICC - SUPPLY CURRENT - mA 4 ICC - SUPPLY CURRENT - mA VOL - OUTPUT LOW VOLTAGE DROP - V 5 0 50 100 150 Rg - SERIES LOAD RESISTANCE - Figure 11. Propagation delay vs. Rg. 200 300 200 100 TPLH TPHL 0 0 20 40 60 80 Cg - LOAD CAPACITANCE - nF Figure 12. Propagation delay vs. Cg. 100 25 35 IF - FORWARD CURRENT - mA VO - OUTPUT VOLTAGE - V 30 25 20 15 10 5 0 -5 0 1 2 3 4 5 20 15 10 5 0 1.2 6 IF - FORWARD LED CURRENT - mA 1 50% DUTY CYCLE 1.8 8 0.1 F IF = 7 to 16 mA 500 1.6 Figure 14. Input current vs. forward voltage. Figure 13. Transfer characteristics. + 10 KHz - 1.4 VF - FORWARD VOLTAGE - V 2 IF V = 15 + CC - to 30 V 7 tr tf VO 3 6 90% 75 50% VOUT 1.5 nF 4 10% 5 tPLH tPHL Figure 15. Propagation delay test circuits and waveforms. VCM IF 1 5V t 0.1 F A B V 8 2 VO 3 6 4 5 + - VCC = 30 V VO - Figure 16. CMR test circuits and waveforms. 10 VOH SWITCH AT A: IF = 10 mA SWITCH AT B: IF = 0 mA + t t VO VCM = 1000 V VCM 0V 7 + - = VOL Applications Information Eliminating Negative IGBT Gate Drive To keep the IGBT firmly off, the HCPL-3020 and HCPL0302 have a very low maximum VOL specification of 1.0 V. Minimizing Rg and the lead inductance from the HCPL-3020 or HCPL-0302 to the IGBT gate and emitter (possibly by mounting the HCPL-3020 or HCPL-0302 on a small PC board directly above the IGBT) can eliminate the need for negative IGBT gate drive in many applications as shown in Figure 17. Care should be taken with such a PC board design to avoid routing the IGBT collector or emitter traces close to the HCPL-3020 or HCPL-0302 input as this can result in unwanted coupling of transient signals into the input of HCPL-3020 or HCPL-0302 and degrade performance. (If the IGBT drain must be routed near the HCPL-3020 or HCPL-0302 input, then the LED should be reverse biased when in the off state, to prevent the transient signals coupled from the IGBT drain from turning on the HCPL-3020 or HCPL-0302. HCPL-3020/0302 +5 V 1 270 CONTROL INPUT 74XXX OPEN COLLECTOR 8 0.1 F 2 7 3 6 4 5 + - VCC = 15 V Rg Figure 17. Recommended LED drive and application circuit for HCPL-3020 and HCPL-0302. 11 + HVDC Q1 3-PHASE AC Q2 - HVDC Selecting the Gate Resistor (Rg) for HCPL-3020 Step 1: Calculate Rg minimum from the IOL peak specification. The IGBT and Rg in Figure 17 can be analyzed as a simple RC circuit with a voltage supplied by the HCPL-3020. Rg VCC - VOL IOLPEAK = 24 - 1 0.4 = 57.5 The VOL value of 1 V in the previous equation is the VOL at the peak current of 0.4 A. (See Figure 4). Step 2: Check the HCPL-3020 power dissipation and increase Rg if necessary. The HCPL-3020 total power dissipation (PT ) is equal to the sum of the emitter power (PE) and the output power (PO). PT = PE + PO PE = IF * VF * Duty Cycle PO = PO(BIAS) + PO(SWITCHING) = ICC * VCC + ESW (Rg;Qg) * f = (ICCBIAS + KICC * Qg * f ) * VCC + ESW (Rg;Qg) * f where KICC * Qg * f is the increase in ICC due to switching and KICC is a constant of 0.001 mA/(nC*kHz). For the circuit in Figure 17 with IF (worst case) = 10 mA, Rg = 57.5 , Max Duty Cycle = 80%, Qg = 100 nC, f = 20 kHz and TAMAX = 85C: PE = 10 mA * 1.8 V * 0.8 = 14 mW PO = [3 mA + (0.001 mA/nC * kHz) * 20 kHz * 100 nC] * 24 V + 0.3mJ * 20 kHz = 126 mW < 250 mW (PO(MAX)) @ 85C The value of 3 mA for ICC in the previous equation is the max. ICC over entire operating temperature range. Since PO for this case is less than PO(MAX), Rg = 57.5 is alright for the power dissipation. Esw - ENERGY PER SWITCHING CYCLE - J 4.0 Qg = 50 nC Qg = 100 nC Qg = 200 nC 3.5 3.0 Qg = 400 nC 2.5 2.0 1.5 1.0 0.5 0 0 20 40 60 80 100 Rg - GATE RESISTANCE - Figure 18. Energy dissipated in the HCPL-3020 and HCPL-0302 and for each IGBT switching cycle. 12 LED Drive Circuit Considerations for Ultra High CMR Performance Without a detector shield, the dominant cause of optocoupler CMR failure is capacitive coupling from the input side of the optocoupler, through the package, to the detector IC as shown in Figure 19. The HCPL-3020 and HCPL-0302 improve CMR performance by using a detector IC with an optically transparent Faraday shield, which diverts the capacitively coupled current away from the sensitive IC circuitry. However, this shield does not eliminate the capacitive coupling between the LED and optocoupler pins 5-8 as shown in Figure 20. This capacitive coupling causes 1 CLEDP 2 perturbations in the LED current during common mode transients and becomes the major source of CMR failures for a shielded optocoupler. The main design objective of a high CMR LED drive circuit becomes keeping the LED in the proper state (on or off ) during common mode transients. For example, the recommended application circuit (Figure 17), can achieve 10 kV/s CMR while minimizing component complexity. Techniques to keep the LED in the proper state are discussed in the next two sections. 8 1 7 2 CLEDO1 8 CLEDP 7 CLEDO2 3 CLEDN 4 6 3 5 4 Figure 19. Optocoupler input to output capacitance model for unshielded optocouplers. +5 V 1 2 + VSAT - 1 0.1 F 7 6 CLEDN 4 + - SHIELD VCC = 18 V Rg 5 2 *** Q1 8 +5 V 3 4 CLEDN SHIELD CLEDN 7 6 SHIELD 5 Figure 22. Not recommended open collector drive circuit. Figure 21. Equivalent circuit for figure 15 during common mode transient. CLEDP CLEDP ILEDN 4 + - 2 3 *** VCM 1 8 +5 V * THE ARROWS INDICATE THE DIRECTION OF CURRENT FLOW DURING -dVCM/dt. 7 6 5 Figure 23. Recommended LED drive circuit for ultra-high CMR IPM dead time and propagation delay specifications. 13 Figure 20. Optocoupler Input to output capacitance model for shielded optocouplers. ILEDP 3 5 SHIELD 8 CLEDP 6 CLEDN CMR with the LED On (CMRH) A high CMR LED drive circuit must keep the LED on during common mode transients. This is achieved by overdriving the LED current beyond the input threshold so that it is not pulled below the threshold during a transient. A minimum LED current of 7 mA provides adequate margin over the maximum IFLH of 6 mA to achieve 10 kV/s CMR. CMR with the LED Off (CMRL) A high CMR LED drive circuit must keep the LED off (VF VF(OFF)) during common mode transients. For example, during a -dVCM/dt transient in Figure 21, the current flowing through CLEDP also flows through the RSAT and VSAT of the logic gate. As long as the low state voltage developed across the logic gate is less than VF(OFF) the LED will remain off and no common mode failure will occur. The open collector drive circuit, shown in Figure 22, cannot keep the LED off during a +dVCM/dt transient, since all the current flowing through CLEDN must be supplied by the LED, and it is not recommended for applications requiring ultra high CMR1 performance. The alternative drive circuit, which likes the recommended application circuit (Figure 17), does achieve ultra high CMR performance by shunting the LED in the off state. Dead Time and Propagation Delay Specifications The HCPL-3020 and HCPL-0302 include a Propagation Delay Difference (PDD) specification intended to help designers minimize "dead time" in their power inverter designs. Dead time is the time high and low side power transistors are off. Any overlap in Ql and Q2 conduction will result in large currents flowing through the power devices from the high voltage to the low-voltage motor rails. To minimize dead time in a given design, the turn on of LED2 should be delayed (relative to the turn off of LED1) so that under worst-case conditions, transistor Q1 has just turned off when transistor Q2 turns on, as shown in Figure 24. The amount of delay necessary to achieve this condition is equal to the maximum value of the propagation delay difference specification, PDD max, which is specified to be 500 ns over the operating temperature range of -40 to 100C. Delaying the LED signal by the maximum propagation delay difference ensures that the minimum dead time is zero, but it does not tell a designer what the maximum dead time will be. The maximum dead time is equivalent to the difference between the maximum and minimum propagation delay difference specification as shown in Figure 25. The maximum dead time for the HCPL-3020 and HCPL-0302 is 1 ms (= 0.5 s - (-0.5 s)) over the operating temperature range of -40C to 100C. Note that the propagation delays used to calculate PDD and dead time are taken at equal temperatures and test conditions since the optocouplers under consideration are typically mounted in close proximity to each other and are switching identical IGBTs. 14 ILED1 ILED1 VOUT1 VOUT1 Q1 ON Q1 ON Q1 OFF Q1 OFF Q2 ON VOUT2 Q2 OFF Q2 ON VOUT2 Q2 OFF ILED2 ILED2 tPHL MIN tPHL MAX tPHL MAX tPLH tPLH MIN MIN PDD* MAX = (tPHL- tPLH)MAX = tPHL MAX - tPLH MIN tPLH MAX (tPHL-tPLH) MAX *PDD = PROPAGATION DELAY DIFFERENCE NOTE: FOR PDD CALCULATIONS THE PROPAGATION DELAYS ARE TAKEN AT THE SAME TEMPERATURE AND TEST CONDITIONS. PDD* MAX MAXIMUM DEAD TIME (DUE TO OPTOCOUPLER) = (tPHL MAX - tPHL MIN) + (tPLH MAX - tPLH MIN) = (tPHL MAX - tPLH MIN) - (tPHL MIN - tPLH MAX) = PDD* MAX - PDD* MIN Figure 24. Minimum LED skew for zero dead time. *PDD = PROPAGATION DELAY DIFFERENCE NOTE: FOR DEAD TIME AND PDD CALCULATIONS ALL PROPAGATION DELAYS ARE TAKEN AT THE SAME TEMPERATURE AND TEST CONDITIONS. Figure 25. Waveforms for dead time. For product information and a complete list of distributors, please go to our web site: www.avagotech.com Avago, Avago Technologies, and the A logo are trademarks of Avago Technologies, Pte. in the United States and other countries. Data subject to change. Copyright (c) 2006 Avago Technologies Pte. All rights reserved. Obsoletes 5989-2947EN AV01-0367EN - August 2, 2006 15