HERMETIC/HI-REL OPTOCOUPLERS H 90 V/1.0 , Hermetically Sealed, Power MOSFET Optocoupler Technical Data HSSR-711X* 5962-9314001 *See matrix for available extensions Features Applications * Dual Marked with Device Part Number and DESC Standard Military Drawing * ac/dc Signal & Power Switching * Compact Solid-State Bidirectional Switch * Manufactured and Tested on a MIL-PRF-38534 Certified Line * QML-38534 * MIL-PRF-38534 Class H * Space Level Processing Available * Hermetically Sealed 8-Pin Dual In-Line Package * Small Size and Weight * Performance Guaranteed over -55C to +125C * Connection A 0.8 A, 1.0 * Connection B 1.6 A, 0.25 * 1500 Vdc Withstand Test Voltage * High Transient Immunity * 5 Amp Output Surge Current * Military and Space * High Reliability Systems * Standard 28 Vdc and 48 Vdc Load Driver * Standard 24 Vac Load Driver * Aircraft Controls * ac/dc Electromechanical and Solid State Relay Replacement * I/O Modules * Harsh Industrial Environments Description The HSSR-7110, HSSR-7111 and SMD 5962-9314001 are single channel power MOSFET optocouplers, constructed in eight-pin, hermetic, dual-in-line, ceramic packages. The devices operate exactly like a solid-state relay. The products are capable of operation and storage over the full military temperature range and can be purchased as a standard product (HSSR-7110), with full MIL-PRF-38534 Class H testing (HSSR-7111), or from the DESC Standard Military Drawing (SMD) 5962-93140. These devices may be purchased with a variety of lead bend and plating options. See Selection Guide Table for details. Standard Military Drawing (SMD) parts are available for each lead style. Functional Diagrams CONNECTION B DC CONNECTION CONNECTION A AC/DC CONNECTION IO IO 1 NC 8 1 NC + 8 IF IF + 2 * 7 VO VF _ 3 4 NC * + _ 3 6 _ 5 VF 2 4 NC * * 7 6 + VO _ TRUTH TABLE INPUT OUTPUT H CLOSED L OPEN 5 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. 5965-1142E 1-593 All devices are manufactured and tested on a MIL-PRF-38534 certified line and are included in the DESC Qualified Manufacturers List, QML-38534 for Hybrid Microcircuits. Each device contains an AlGaAs light emitting diode optically coupled to a photovoltaic diode stack which drives two discrete power MOSFETs. The device operates as a solid-state replacement for single-pole, normally open, (1 Form A) relays used for general purpose switching of signals and loads in high reliability applications. The devices feature logic level input control and very low output on-resistance, making them suitable for both ac and dc loads. Connection A, as shown in the Functional Diagram, allows the device to switch either ac or dc loads. Connection B, with the polarity and pin configuration as shown, allows the device to switch dc loads only. The advantage of Connection B is that the on-resistance is significantly reduced, and the output current capability increases by a factor of two. Selection Guide-Package Styles and Lead Configuration Options HP Part # and Options Commercial MIL-PRF-38534 Class H Standard Lead Finish Solder Dipped Butt Joint/Gold Plate Gull Wing/Soldered Crew Cut/Gold Plate SMD Part # Prescript for all below Either Gold or Soldered Gold Plate Solder Dipped Butt Joint/Gold Plate Butt Joint/Soldered Gull Wing/Soldered Crew Cut/Gold Plate Crew Cut/Soldered The devices are convenient replacements for mechanical and solid state relays where high component reliability with standard footprint lead configuration is desirable. Devices may be purchased with a variety of lead bend and plating options. See Selection Guide table for details. Standard Military Drawing (SMD) parts are available for each package and lead style. The HSSR-7110, HSSR-7111, and SMD 5962-93140 are designed to switch loads on 28 Vdc power systems. They meet 80 V surge and 600 V spike requirements. HSSR-7110 HSSR-7111 Gold Option #200 Option #100 Option #300 Option #600 59629314001HPX 9314001HPC 9314001HPA 9314001HYC 9314001HYA 9314001HXA 9314001HZC 9314001HZA Outline Drawing 9.40 (0.370) 9.91 (0.390) 0.76 (0.030) 1.27 (0.050) 8-pin DIP Through Hole 8.13 (0.320) MAX. 7.16 (0.282) 7.57 (0.298) 4.32 (0.170) MAX. 0.51 (0.020) MIN. 2.29 (0.090) 2.79 (0.110) 3.81 (0.150) MIN. 0.51 (0.020) MAX. NOTE: DIMENSIONS IN MILLIMETERS (INCHES). 1-594 0.20 (0.008) 0.33 (0.013) 7.36 (0.290) 7.87 (0.310) HERMETIC/HI-REL OPTOCOUPLERS Device Marking HP LOGO HP P/N DESC SMD* DESC SMD* PIN ONE/ ESD IDENT HP QYYWWZ XXXXXX XXXXXXX XXX USA 50434 COMPLIANCE INDICATOR,* DATE CODE, SUFFIX (IF NEEDED) COUNTRY OF MFR. HP FSCN* * QUALIFIED PARTS ONLY Absolute Maximum Ratings Storage Temperature Range ........................................ -65C to +150C Operating Ambient Temperature - TA .......................... -55C to +125C Junction Temperature - TJ ......................................................... +150C Operating Case Temperature - TC ......................................... +145C[1] Lead Solder Temperature ............................................... 260C for 10 s (1.6 mm below seating plane) Average Input Current - IF ........................................................... 20 mA Peak Repetitive Input Current - IFPK ............................................ 40 mA (Pulse Width < 100 ms; duty cycle < 50%) Peak Surge Input Current - IFPK surge ....................................... 100 mA (Pulse Width < 0.2 ms; duty cycle < 0.1%) Reverse Input Voltage - VR ............................................................... 5 V Average Output Current - Figure 2 Connection A - IO ....................................................................... 0.8 A Connection B - IO ...................................................................... 1.6 A Single Shot Output Current - Figure 3 Connection A - IOPK surge (Pulse width < 10 ms) ...................... 5.0 A Connection B - IOPK surge (Pulse width < 10 ms) ................... 10.0 A Output Voltage Connection A - VO ...................................................... -90 V to +90 V Connection B - VO .......................................................... 0 V to +90 V Average Output Power Dissipation - Figure 4 ....................... 800 mW[2] Thermal Resistance Maximum Output MOSFET Junction to Case - JC = 15C/W ESD Classification (MIL-STD-883, Method 3015) .......................................... (), Class 2 Recommended Operating Conditions Parameter Symbol Min. Max. Units Input Current (on) IF(ON) 5 20 mA Input Voltage (off) VF(OFF) 0 0.6 V TA -55 +125 C Operating Temperature 1-595 Hermetic Optocoupler Options Option 100 Description Surface mountable hermetic optocoupler with leads trimmed for butt joint assembly. This option is available on commercial and hi-rel product. 4.32 (0.170) MAX. 0.51 (0.020) MIN. 2.29 (0.090) 2.79 (0.110) 1.14 (0.045) 1.40 (0.055) 0.20 (0.008) 0.33 (0.013) 0.51 (0.020) MAX. 7.36 (0.290) 7.87 (0.310) NOTE DIMENSIONS IN MILLIMETERS (INCHES) 200 Lead finish is solder dipped rather than gold plated. This option is available on commercial and hi-rel product. DESC Drawing part numbers contain provisions for lead finish. 300 Surface mountable hermetic optocoupler with leads cut and bent for gull wing assembly. This option is available on commercial and hi-rel product. This option has solder dipped leads. 5.57 (0.180) MAX. 0.51 (0.020) MIN. 2.29 (0.090) 2.79 (0.110) 600 1.40 (0.055) 1.65 (0.065) 5 MAX. 0.51 (0.020) MAX. 5.57 (0.180) MAX. 0.20 (0.008) 0.33 (0.013) 9.65 (0.380) 9.91 (0.390) Surface mountable hermetic optocoupler with leads trimmed for butt joint assembly. This option is available on commercial and hi-rel product. 3.81 (0.150) MAX. 0.51 (0.020) MIN. 2.29 (0.090) 2.79 (0.110) Note: Dimensions in millimeters (inches). 1-596 0.20 (0.008) 0.33 (0.013) 1.02 (0.040) TYP. 7.36 (0.290) 7.87 (0.310) HERMETIC/HI-REL OPTOCOUPLERS Electrical Specifications TA =-55C to +125C, unless otherwise specified. See note 9. Parameter Output Withstand Voltage Output Connection OnA Resistance Sym. Group A, Subgroup |VO(OFF)| 1, 2, 3 VF = 0.6 V, IO = 10 A R(ON) 1, 2, 3 IF = 10 mA, IO = 800 mA, (pulse duration 30 ms) 0.40 1.0 IF = 10 mA, IO = 1.6 A, (pulse duration 30 ms) 0.12 0.25 10-4 1.24 Connection B Output Leakage Current Test Conditions Min. Typ.* Max. Units 90 IO(OFF) 1, 2, 3 VF = 0.6 V, VO = 90 V, Input Forward Voltage VF 1, 2, 3 IF = 10 mA 1.0 Input Reverse Breakdown Voltage VR 1, 2, 3 IR = 100 A 5.0 Input-Output Insulation II-O 1 Turn On Time tON 9, 10, 11 IF = 10 mA, VDD = 28 V, IO = 800 mA Turn Off Time tOFF 9,10,11 IF = 10 mA, VDD = 28 V, IO = 800 mA Output Transient Rejection dVo dt 9 VPEAK = 50 V, CM = 1000 pF, CL = 15 pF, RM 1 M Input-Output Transient Rejection dVio dt 9 VDD = 5 V, VI-O(PEAK) = 50 V, RL = 20 k, CL = 15 pF 110 Fig. V 5 6,7 10 A 8 1.7 V 9 Notes 3 V RH 45%, t = 5 s, VI-O = 1500 Vdc, TA = 25C 1.0 A 1.25 6.0 ms 1,10, 11,12, 13 0.02 0.25 ms 1,10, 14,15 1000 V/s 17 500 V/s 18 4, 5 *All typical values are at TA = 25C, IF(ON) = 10 mA, VF(OFF) = 0.6 V unless otherwise specified. 1-597 Typical Characteristics All typical values are at TA = 25C, IF(ON) = 10 mA, VF(OFF) = 0.6 V unless otherwise specified. Parameter Output Off-Capacitance Output Offset Voltage Input Diode Temperature Coefficient Input Capacitance Input-Output Capacitance Input-Output Resistance Turn On Time With Peaking Symbol CO(OFF) |VOS| VF/TA Test Conditions VO = 28 V, f = 1 MHz IF = 10 mA, IO = 0 mA IF = 10 mA Typ. 145 2 -1.4 Units pF V mV/C CIN CI-O RI-O VF = 0 V, f = 1 MHz VI-O = 0 V, f = 1 MHz VI-O = 500 V, t = 60 s 20 1.5 1013 pF pF tON IFPK = 100 mA, IFSS = 10 mA VDD = 28 V, IO = 800 mA 0.22 ms Fig. 16 19 Notes 7 8 4 4 1 6 Notes: 1. Maximum junction to case thermal resistance for the device is 15C/W, where case temperature, TC, is measured at the center of the package bottom. 2. For rating, see Figure 4. The output power PO rating curve is obtained when the part is handling the maximum average output current IO as shown in Figure 2. 3. During the pulsed RON measurement (IO duration <30 ms), ambient (TA) and case temperature (TC) are equal. 4. Device considered a two terminal device: pins 1 through 4 shorted together and pins 5 through 8 shorted together. 5. This is a momentary withstand test, not an operating condition. 6. For a faster turn-on time, the optional peaking circuit shown in Figure 1 may be implemented. 7. VOS is a function of IF, and is defined between pins 5 and 8, with pin 5 as the reference. VOS must be measured in a stable ambient (free of temperature gradients). 8. Zero-bias capacitance measured between the LED anode and cathode. 9. Standard parts receive 100% testing at 25C (Subgroups 1 and 9). SMD and class H parts receive 100% testing at 25C, 125C and -55C (Subgroups 1 and 9, 2 and 10, 3 and 11 respectively). CAUTION: Maximum Switching Frequency - Care should be taken during repetitive switching of loads so as not to exceed the maximum output current, maximum output power dissipation, maximum case temperature, and maximum junction temperature. HSSR-7110 VCC (+5V) 1 8 2 7 3 6 4 5 IF + VF _ R2 1200 R1 330 R3 C 15 F IN 1/4 54ACTOO 1/4 54ACTOO* R1 = REQUIRED CURRENT LIMITING RESISTOR FOR I =F 10 mA. (0N) R2 = PULL-UP RESISTOR FOR VF (OFF) < 600 mV; IF (V - V CC) < 600 OH mV, OMIT R2. R3, C = OPTIONAL PEAKING CIRCUIT. TYPICAL VALUES * USE SECOND GATE IF I F (PK) > 50 mA REMINDER: TIE ALL UNUSED INPUTS TO GROUND OR V CC Figure 1. Recommended Input Circuit. 1-598 R3 () I F (PK) (mA) HSSR-7110 t ON (ms) - 330 100 33 10 (NO PK) 20 40 100 2.0 1.0 0.48 0.22 0.6 0.4 0 -55 CONNECTION - A IF 10 mA CA= 40 C/W CA= 80 C/W -25 5 0.8 10 9 CONNECTION-B 8 7 6 65 95 125 10 155 200 400 600 800 1.8 1.6 NORMALIZED TYPICAL OUTPUT RESISTANCE 1.06 1.04 1.02 1.00 0.98 0.8 CONNECTION - A IF > 10 mA IO = 800 mA (PULSE DURATION 30 ms) 0.6 1.4 1.2 1.0 0.8 65 95 0.6 -55 125 -25 5 35 65 95 T A - AMBIENT TEMPERATURE - C T A - AMBIENT TEMPERATURE - C Figure 5. Normalized Typical Output Withstand Voltage vs. Temperature. Figure 6. Normalized Typical Output Resistance vs. Temperature. 10 -8 35 65 95 125 155 0.4 CONNECTION - A IF > 10 mA IO (PULSE DURATION 30 ms) 0.2 0 TA = 125C -0.2 TA = 25C -0.4 TA = -55C 125 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 VO - OUTPUT VOLTAGE - V Figure 7. Typical On State Output I-V Characteristics. 10 -1 CONNECTION A V F = 0.6V VO = 90V 10 -2 I F - INPUT FORWARD CURRENT - A I O(OFF) - OUTPUT LEAKAGE CURRENT - A 10 -7 5 -0.6 0.94 35 -25 Figure 4. Output Power Rating vs. Ambient Temperature. 0.96 5 CONNECTION - A IF 10 mA CA= 40 C/W CA= 80 C/W T A - AMBIENT TEMPERATURE - C Figure 3. Single Shot (non-repetitive) Output Current vs. Pulse Duration. VF = 0.6V IO = 10 A -25 0 -55 1000 PULSE DURATION - ms 1.10 NORMALIZED TYPICAL OUTPUT WITHSTAND VOLTAGE 0.2 CONNECTION-A 3 35 Figure 2. Maximum Average Output Current Rating vs. Ambient Temperature. 0.92 -55 0.4 4 T A - AMBIENT TEMPERATURE - C 1.08 0.6 5 I O - OUTPUT CURRENT - A 0.2 1.0 IF 10mA 11 P O - OUTPUT POWER DISSIPATION - W IOPK SURGE - OUTPUT CURRENT - A I O - OUTPUT CURRENT - A 0.8 HERMETIC/HI-REL OPTOCOUPLERS 12 1.0 10 -9 10 -10 10 -3 TA = 125C 10 -4 TA = 25C 10 -5 TA = -55C 10 -11 20 35 65 95 TA - TEMPERATURE - C Figure 8. Typical Output Leakage Current vs. Temperature. 125 10 -6 0.4 0.6 0.8 1.0 1.2 1.4 1.6 V F - INPUT FORWARD VOLTAGE - V Figure 9. Typical Input Forward Current vs. Input Forward Voltage. 1-599 VDD 50% PULSE GEN. Z O = 50 t f = t r = 5ns 50% IF RL HSSR-7110 P.W. = 15 ms 1 8 2 7 3 6 4 5 VO MONITOR NODE IF + VF _ VO 90% C L= 25 pF (C L INCLUDES PROBE AND FIXTURE CAPACITANCE) IF MONITOR 10% R (MONITOR) 200 t ON t OFF GND GND Figure 10. Switching Test Circuit for tON, tOFF. 2.6 2.0 1.8 1.6 1.4 1.2 -25 5 35 65 95 2.2 1.8 1.4 1.0 14.2 14.0 13.8 13.6 35 65 0.6 0.4 10 20 95 125 TA - TEMPERATURE - C Figure 14. Typical Turn Off Time vs. Temperature. 30 40 50 60 70 80 90 Figure 13. Typical Turn On Time vs. Voltage. 440 35 CONNECTION A f = 1MHz TA = 25C 400 30 25 20 15 360 320 280 240 200 160 120 5 5 0.8 V DD - VOLTAGE - V 10 13.4 -25 1.0 0 20 CONNECTION A V DD = 28V IO = 800mA TA = 25C 40 TOFF - TURN OFF TIME - s TOFF - TURN OFF TIME - s 15 45 CONNECTION A I F = 10mA VDD = 28V IO = 800mA 14.4 1-600 10 Figure 12. Typical Turn On Time vs. Input Current. 15.0 13.2 -55 1.2 I F - INPUT CURRENT - mA Figure 11. Typical Turn On Time vs. Temperature. 14.6 1.4 0 5 TA - TEMPERATURE - C 14.8 1.6 0.2 0.2 125 CONNECTION - A IF = 10 mA IO = 800 mA TA = 25C 1.8 0.6 1.0 0.8 -55 CONNECTION A V DD = 28V IO = 800mA TA = 25C C O(OFF) - OUTPUT OFF CAPACITANCE - pF 2.2 2.0 3.0 CONNECTION A IF = 10mA VDD = 28V IO = 800mA T ON - TURN ON TIME - ms TON - TURN ON TIME - ms 2.4 T ON - TURN ON TIME - ms 2.6 5 10 15 I F - INPUT CURRENT - mA Figure 15. Typical Turn Off Time vs. Input Current. 20 0 5 10 15 20 25 VO(OFF) - OUTPUT VOLTAGE - V Figure 16. Typical Output Off Capacitance vs. Output Voltage. 30 HERMETIC/HI-REL OPTOCOUPLERS HSSR-7110 VM 1 8 2 7 3 6 4 5 MONITOR NODE IF INPUT OPEN + VF _ RM CM + VPEAK _ PULSE GENERATOR CM INCLUDES PROBE AND FIXTURE CAPACITANCE RM INCLUDES PROBE AND FIXTURE RESISTANCE 90% 90% V PEAK 10% 10% tr tf VM (MAX) 5V (0.8) V(PEAK) (0.8) V (PEAK) dVo = OR tf dt tr OVERSHOOT ON V PEAK IS TO BE 10%. Figure 17. Output Transient Rejection Test Circuit. 1-601 V DD HSSR-7110 RL 1 8 2 7 3 6 4 5 VO IF + VF _ S1 A CL (C L INCLUDES PROBE PLUS FIXTURE CAPACITANCE ) B V in VI-O + _ PULSE GENERATOR 90% 90% V I-O(PEAK) 10% 10% tf tr VO(OFF) S1 AT A (VF = 0V) VO(OFF) (min) 3.25V VO(ON) (max) 0.8 VO(ON) S1 AT B (IF = 10mA) (0.8) VI-O(PEAK) (0.8) V I-O (PEAK) dV I-O = OR dt tr tf OVERSHOOT ON V I-O(PEAK) IS TO BE 10% Figure 18. Input-Output Transient Rejection Test Circuit. 1-602 HERMETIC/HI-REL OPTOCOUPLERS ISOTHERMAL CHAMBER HSSR-7110 IF 1 8 2 7 _ 3 6 + + DIGITAL NANOVOLTMETER VOS 4 5 _ Figure 19. Voltage Offset Test Setup. VO (SEE NOTE) HSSR-7110 1 8 2 7 3 6 4 5 R OUT 1.0 V IN R IN 200 5.5 V R OUT 1.0 NOTE: IN ORDER TO DETERMINE VOUT CORRECTLY, THE CASE TO AMBIENT THERMAL IMPEDANCE MUST BE MEASURED FOR THE BURN-IN BOARDS TO BE USED. THEN, KNOWING CA, DETERMINE THE CORRECT OUTPUT CURRENT PER FIGURES 2 AND 4 TO INSURE THAT THE DEVICE MEETS THE DERATING REQUIREMENTS AS SHOWN. Figure 20. Burn-In Circuit. T je 104 Tjd T jf1 15 T jf2 15 15 TC CA TA Tje = LED JUNCTION TEMPERATURE T jf1= FET 1 JUNCTION TEMPERATURE T jf2 = FET 2 JUNCTION TEMPERATURE Tjd = FET DRIVER JUNCTION TEMPERATURE TC = CASE TEMPERATURE (MEASURED AT CENTER OF PACKAGE BOTTOM) TA = AMBIENT TEMPERATURE (MEASURED 6" AWAY FROM THE PACKAGE) CA = CASE-TO-AMBIENT THERMAL RESISTANCE ALL THERMAL RESISTANCE VALUES ARE IN C/W Figure 21. Thermal Model. 1-603 Applications Information Thermal Model The steady state thermal model for the HSSR-7110 is shown in Figure 21. The thermal resistance values given in this model can be used to calculate the temperatures at each node for a given operating condition. The thermal resistances between the LED and other internal nodes are very large in comparison with the other terms and are omitted for simplicity. The components do, however, interact indirectly through CA, the case-to-ambient thermal resistance. All heat generated flows through CA, which raises the case temperature TC accordingly. The value of CA depends on the conditions of the board design and is, therefore, determined by the designer. The maximum value for each output MOSFET junction-to-case thermal resistance is specified as 15C/W. The thermal resistance from FET driver junction-to-case is also 15C/W. The power dissipation in the FET driver, however, is negligible in comparison to the MOSFETs. On-Resistance and Rating Curves The output on-resistance, RON, specified in this data sheet, is the resistance measured across the output contact when a pulsed current signal (IO = 800 mA) is applied to the output pins. The use of a pulsed signal ( 30 ms) implies that each junction temperature is equal to the ambient and case temperatures. The steady-state resistance, RSS, on the other hand, is the value of 1-604 the resistance measured across the output contact when a DC current signal is applied to the output pins for a duration sufficient to reach thermal equilibrium. RSS includes the effects of the temperature rise of each element in the thermal model. Rating curves are shown in Figures 2 and 4. Figure 2 specifies the maximum average output current allowable for a given ambient temperature. Figure 4 specifies the output power dissipation allowable for a given ambient temperature. Above 55C (for CA = 80C/W) and 107C (for CA = 40C/W), the maximum allowable output current and power dissipation are related by the expression RSS = PO(max)/ (IO(max))2 from which RSS can be calculated. Staying within the safe area assures that the steady-state junction temperatures remain less than 150C. As an example, for TA = 95C and CA = 80C/W, Figure 2 shows that the output current should be limited to less than 610 mA. A check with Figure 4 shows that the output power dissipation at TA = 95C and IO = 610 mA, will be limited to less than 0.35 W. This yields an RSS of 0.94 . Design Considerations for Replacement of Electro-Mechanical Relays The HSSR-7110 family can replace electro-mechanical relays with comparable output voltage and current ratings. The following design issues need to be considered in the replacement circuit. Input Circuit: The drive circuit of the electro-mechanical relay coil needs to be modified so that the average forward current driving the LED of the HSSR7110 does not exceed 20 mA. A nominal forward drive current of 10 mA is recommended. A recommended drive circuit with 5 volt VCC and CMOS logic gates is shown in Figure 1. If higher VCC voltages are used, adjust the current limiting resistor to a nominal LED forward current of 10 mA. One important consideration to note is that when the LED is turned off, no more than 0.6 volt forward bias should be applied across the LED. Even a few microamps of current may be sufficient to turn on the HSSR7110, although it may take a considerable time. The drive circuit should maintain at least 5 mA of LED current during the ON condition. If the LED forward current is less than the 5 mA level, it will cause the HSSR-7110 to turn on with a longer delay. In addition, the power dissipation in the output power MOSFETs increases, which, in turn, may violate the power dissipation guidelines and affect the reliability of the device. Output Circuit: Unlike electromechanical relays, the designer should pay careful attention to the output on-resistance of solid state relays. The previous section, "OnResistance and Rating Curves" describes the issues that need to be considered. In addition, for strictly dc applications the designer has an advantage using Connection B which has twice the backs, lightning strikes, and electro-static voltages that exceed the specifications on this data sheet. For more information on output load and protection refer to Application Note 1047. Output over-voltage protection is yet another important design consideration when replacing electro-mechanical relays with the HSSR-7110. The output power MOSFETs can be protected using Metal oxide varistors (MOVs) or TransZorbs against voltage surges that exceed the 90 volt output withstand voltage rating. Examples of sources of voltage surges are inductive load kick- References: 1. Application Note 1047, "Low On-Resistance Solid State Relays for High Reliability Applications." 2. Reliability Data for HSSR-7110. MIL-PRF-38534 Class H and DESC SMD Test Program Hewlett-Packard's Hi-Rel Optocouplers are in compliance with MIL-PRF-38534 Class H. Class H devices are also in compliance with DESC drawing 5962-93140. Testing consists of 100% screening and quality conformance inspection to MIL-PRF-38534. MOV is a registered trademark of GE/RCA Solid State. TransZorb is a registered trademark of General Semiconductor. 1-605 HERMETIC/HI-REL OPTOCOUPLERS output current rating as Connection A. Furthermore, for dc-only applications, with Connection B the on-resistance is considerably less when compared to Connection A.