GENERAL PURPOSE 6-PIN PHOTOTRANSISTOR OPTOCOUPLERS 4N25 4N37 4N26 H11A1 4N27 H11A2 WHITE PACKAGE (-M SUFFIX) 4N35 H11A4 4N36 H11A5 SCHEMATIC 6 1 4N28 H11A3 1 6 2 5 6 3 NC 4 1 PIN 1. ANODE 2. CATHODE 3. NO CONNECTION 4. EMITTER 5. COLLECTOR 6. BASE 6 1 BLACK PACKAGE (NO -M SUFFIX) 6 1 6 1 6 1 DESCRIPTION The general purpose optocouplers consist of a gallium arsenide infrared emitting diode driving a silicon phototransistor in a 6-pin dual in-line package. FEATURES * Also available in white package by specifying -M suffix, eg. 4N25-M * UL recognized (File # E90700) * VDE recognized (File # 94766) - Add option V for white package (e.g., 4N25V-M) - Add option 300 for black package (e.g., 4N25.300) APPLICATIONS * Power supply regulators * Digital logic inputs * Microprocessor inputs (c) 2005 Fairchild Semiconductor Corporation Page 1 of 15 6/15/05 GENERAL PURPOSE 6-PIN PHOTOTRANSISTOR OPTOCOUPLERS 4N25 4N37 4N26 H11A1 4N27 H11A2 4N28 H11A3 4N35 H11A4 4N36 H11A5 ABSOLUTE MAXIMUM RATINGS (TA = 25C unless otherwise specified) Parameter Symbol Value Units Storage Temperature TSTG -55 to +150 C Operating Temperature TOPR -55 to +100 C Wave solder temperature (see page 14 for reflow solder profiles) TSOL 260 for 10 sec C TOTAL DEVICE Total Device Power Dissipation @ TA = 25C Derate above 25C PD 250 3.3 (non-M), 2.94 (-M) mW EMITTER DC/Average Forward Input Current IF 100 (non-M), 60 (-M) mA Reverse Input Voltage VR 6 V IF(pk) 3 A Forward Current - Peak (300s, 2% Duty Cycle) LED Power Dissipation @ TA = 25C Derate above 25C PD 150 (non-M), 120 (-M) mW 2.0 (non-M), 1.41 (-M) mW/C DETECTOR Collector-Emitter Voltage VCEO 30 V Collector-Base Voltage VCBO 70 V Emitter-Collector Voltage VECO 7 V 150 mW 2.0 (non-M), 1.76 (-M) mW/C Detector Power Dissipation @ TA = 25C Derate above 25C (c) 2005 Fairchild Semiconductor Corporation PD Page 2 of 15 6/15/05 GENERAL PURPOSE 6-PIN PHOTOTRANSISTOR OPTOCOUPLERS 4N25 4N37 4N26 H11A1 4N27 H11A2 4N28 H11A3 4N35 H11A4 4N36 H11A5 ELECTRICAL CHARACTERISTICS (TA = 25C unless otherwise specified) INDIVIDUAL COMPONENT CHARACTERISTICS Parameter Test Conditions Symbol Min Typ* Max Unit EMITTER Input Forward Voltage (IF = 10 mA) VF 1.18 1.50 V Reverse Leakage Current (VR = 6.0 V) IR 0.001 10 A DETECTOR Collector-Emitter Breakdown Voltage (IC = 1.0 mA, IF = 0) Collector-Base Breakdown Voltage Emitter-Collector Breakdown Voltage Collector-Emitter Dark Current BVCEO 30 100 (IC = 100 A, IF = 0) BVCBO 70 120 V (IE = 100 A, IF = 0) BVECO 7 10 V (VCE = 10 V, IF = 0) ICEO (VCB = 10 V) ICBO (VCE = 0 V, f = 1 MHz) CCE Collector-Base Dark Current Capacitance V 1 50 nA 20 nA 8 pF ISOLATION CHARACTERISTICS Characteristic Input-Output Isolation Voltage Test Conditions Symbol (Non `-M', Black Package) (f = 60 Hz, t = 1 min) (`-M', White Package) (f = 60 Hz, t = 1 sec) Isolation Resistance Isolation Capacitance (VI-O = 500 VDC) (VI-O = &, f = 1 MHz) (`-M' White Package) VISO RISO CISO Min Typ* Max Units 5300 Vac(rms) 7500 Vac(pk) 1011 0.5 0.2 pF 2 pF Note * Typical values at TA = 25C (c) 2005 Fairchild Semiconductor Corporation Page 3 of 15 6/15/05 GENERAL PURPOSE 6-PIN PHOTOTRANSISTOR OPTOCOUPLERS 4N25 4N37 4N26 H11A1 4N27 H11A2 4N28 H11A3 4N35 H11A4 4N36 H11A5 TRANSFER CHARACTERISTICS (TA = 25C Unless otherwise specified.) DC Characteristic Test Conditions Symbol Device Min 4N35 4N36 4N37 100 H11A1 50 H11A5 30 4N25 4N26 H11A2 H11A3 20 4N27 4N28 H11A4 10 (IF = 10 mA, VCE = 10 V, TA = -55C) 4N35 4N36 4N37 40 (IF = 10 mA, VCE = 10 V, TA = +100C) 4N35 4N36 4N37 40 (IC = 2 mA, IF = 50 mA) 4N25 4N26 4N27 4N28 0.5 4N35 4N36 4N37 0.3 H11A1 H11A2 H11A3 H11A4 H11A5 0.4 (IF = 10 mA, VCE = 10 V) CTR Current Transfer Ratio, Collector to Emitter Collector-Emitter Saturation Voltage VCE (SAT) (IC = 0.5 mA, IF = 10 mA) AC Characteristic Non-Saturated Turn-on Time (IF = 10 mA, VCC = 10 V, RL = 100) (Fig.20) TON 4N25 4N26 4N27 4N28 H11A1 H11A2 H11A3 H11A4 H11A5 Non Saturated Turn-on Time (IC = 2 mA, VCC = 10 V, RL = 100) (Fig.20) TON 4N35 4N36 4N37 (c) 2005 Fairchild Semiconductor Corporation Page 4 of 15 Typ* Max Unit % 2 2 V s 10 s 6/15/05 GENERAL PURPOSE 6-PIN PHOTOTRANSISTOR OPTOCOUPLERS 4N25 4N37 4N26 H11A1 4N27 H11A2 4N28 H11A3 4N35 H11A4 4N36 H11A5 TRANSFER CHARACTERISTICS (TA = 25C Unless otherwise specified.) (Continued) AC Characteristic Test Conditions Symbol (IF = 10 mA, VCC = 10 V, RL = 100) (Fig.20) TOFF Turn-off Time (IC = 2 mA, VCC = 10 V, RL = 100) (Fig.20) Device Min Typ* 4N25 4N26 4N27 4N28 H11A1 H11A2 H11A3 H11A4 H11A5 2 4N35 4N36 4N37 2 Max Unit s 10 * Typical values at TA = 25C (c) 2005 Fairchild Semiconductor Corporation Page 5 of 15 6/15/05 GENERAL PURPOSE 6-PIN PHOTOTRANSISTOR OPTOCOUPLERS 4N25 4N37 4N26 H11A1 4N27 H11A2 4N28 H11A3 4N35 H11A4 4N36 H11A5 TYPICAL PERFORMANCE CURVES Fig. 2 LED Forward Voltage vs. Forward Current (White Package) 1.8 1.8 1.7 1.7 VF - FORWARD VOLTAGE (V) VF - FORWARD VOLTAGE (V) Fig. 1 LED Forward Voltage vs. Forward Current (Black Package) 1.6 1.5 1.4 TA = -55C 1.3 1.2 TA = 25C 1.1 TA = 100C 1.6 1.5 1.4 TA = -55C 1.3 TA = 25C 1.2 TA = 100C 1.1 1.0 1.0 1 10 100 1 10 IF - LED FORWARD CURRENT (mA) 100 IF - LED FORWARD CURRENT (mA) Fig.3 Normalized CTR vs. Forward Current (Black Package) Fig.4 Normalized CTR vs. Forward Current (White Package) 1.4 1.6 VCE = 5.0V TA = 25C Normalized to IF = 10 mA VCE = 5.0V TA = 25C 1.4 1.2 Normalized to IF = 10 mA 1.2 NORMALIZED CTR NORMALIZED CTR 1.0 0.8 0.6 0.4 1.0 0.8 0.6 0.4 0.2 0.2 0.0 0.0 0 5 10 15 20 0 2 IF - FORWARD CURRENT (mA) 4 6 8 10 12 14 16 18 20 IF - FORWARD CURRENT (mA) Fig. 5 Normalized CTR vs. Ambient Temperature (Black Package) Fig. 6 Normalized CTR vs. Ambient Temperature (White Package) 1.6 1.4 1.4 1.2 IF = 5 mA NORMALIZED CTR NORMALIZED CTR IF = 5 mA 1.2 IF = 10 mA 1.0 0.8 0.6 IF = 10 mA 0.8 IF = 20 mA 0.6 Normalized to IF = 10 mA TA = 25C 0.4 Normalized to IF = 10 mA TA = 25C IF = 20 mA 0.4 -75 1.0 0.2 -50 -25 0 25 50 75 100 125 TA - AMBIENT TEMPERATURE (C) (c) 2005 Fairchild Semiconductor Corporation -60 -40 -20 0 20 40 60 80 100 TA - AMBIENT TEMPERATURE (C) Page 6 of 15 6/15/05 GENERAL PURPOSE 6-PIN PHOTOTRANSISTOR OPTOCOUPLERS 4N25 4N37 4N26 H11A1 4N27 H11A2 4N28 H11A3 4N36 H11A5 Fig. 8 CTR vs. RBE (Unsaturated) (White Package) Fig. 7 CTR vs. RBE (Unsaturated) (Black Package) 1.0 1.0 NORMALIZED CTR ( CTRRBE / CTRRBE(OPEN)) NORMALIZED CTR ( CTRRBE / CTRRBE(OPEN)) 4N35 H11A4 0.9 VCE= 5.0 V 0.8 IF = 20 mA 0.7 0.6 IF = 10 mA 0.5 0.4 IF = 5 mA 0.3 0.2 0.1 0.9 IF = 20 mA 0.8 IF = 10 mA 0.7 IF = 5 mA 0.6 0.5 0.4 0.3 0.2 VCE= 5.0 V 0.1 0.0 0.0 10 100 1000 10 100 RBE- BASE RESISTANCE (k) Fig. 9 CTR vs. RBE (Saturated) (Black Package) Fig. 10 CTR vs. RBE (Saturated) (White Package) 1.0 NORMALIZED CTR ( CTRRBE / CTRRBE(OPEN)) NORMALIZED CTR ( CTRRBE / CTRRBE(OPEN)) 1.0 0.9 VCE= 0.3 V 0.8 IF = 20 mA 0.7 0.6 IF = 10 mA 0.5 0.4 IF = 5 mA 0.3 0.2 0.1 0.9 VCE= 0.3 V 0.8 IF = 20 mA 0.7 0.6 IF = 10 mA 0.5 0.4 0.3 IF = 5 mA 0.2 0.1 0.0 0.0 10 100 1000 10 100 RBE- BASE RESISTANCE (k ) 10 1 IF = 2.5 mA 0.1 IF = 10 mA IF = 20 mA IF = 5 mA TA = 25C 0.001 0.01 0.1 1 10 Fig. 12 Collector-Emitter Saturation Voltage vs Collector Current (White Package) VCE (SAT) - COLLECTOR-EMITTER SATURATION VOLTAGE (V) 100 0.01 100 TA = 25C 10 1 IF = 2.5 mA 0.1 IF = 20 mA 0.01 IF = 5 mA 0.001 0.01 IF = 10 mA 0.1 1 10 IC - COLLECTOR CURRENT (mA) IC - COLLECTOR CURRENT (mA) (c) 2005 Fairchild Semiconductor Corporation 1000 RBE- BASE RESISTANCE (k ) Fig. 11 Collector-Emitter Saturation Voltage vs Collector Current (Black Package) VCE (SAT) - COLLECTOR-EMITTER SATURATION VOLTAGE (V) 1000 RBE- BASE RESISTANCE (k) Page 7 of 15 6/15/05 GENERAL PURPOSE 6-PIN PHOTOTRANSISTOR OPTOCOUPLERS 4N25 4N37 4N26 H11A1 4N27 H11A2 4N28 H11A3 1000 1000 IF = 10 mA VCC = 10 V TA = 25C IF = 10 mA VCC = 10 V TA = 25C SWITCHING SPEED - (s) 100 Toff 10 Tf Ton 1 Tr 0.1 100 Toff 10 Ton 1 Tr 1 10 100 0.1 1 10 100 R-LOAD RESISTOR (k) R-LOAD RESISTOR (k) Fig. 16 Normalized ton vs. RBE (White Package) Fig. 15 Normalized ton vs. RBE (Black Package) 5.0 5.0 VCC = 10 V IC = 2 mA RL = 100 4.5 NORMALIZED ton - (ton(RBE) / ton(open)) NORMALIZED ton - (ton(RBE) / ton(open)) Tf 0.1 0.1 4.0 3.5 3.0 2.5 2.0 1.5 1.0 4.5 VCC = 10 V IC = 2 mA RL = 100 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 10 100 1000 10000 10 100000 RBE- BASE RESISTANCE (k ) 1.3 NORMALIZED toff - (toff(RBE) / toff(open)) 1.4 1.3 1.2 1.1 1.0 0.9 0.8 0.7 0.6 VCC = 10 V IC = 2 mA RL = 100 0.4 1000 10000 100000 Fig. 18 Normalized toff vs. RBE (White Package) 1.4 0.5 100 RBE- BASE RESISTANCE (k ) Fig. 17 Normalized toff vs. RBE (Black Package) NORMALIZED toff - (toff(RBE) / toff(open)) 4N36 H11A5 Fig. 14 Switching Speed vs. Load Resistor (White Package) Fig. 13 Switching Speed vs. Load Resistor (Black Package) SWITCHING SPEED - (s) 4N35 H11A4 0.3 1.2 1.1 1.0 0.9 0.8 0.7 0.6 VCC = 10 V IC = 2 mA RL = 100 0.5 0.4 0.3 0.2 0.2 0.1 0.1 10 100 1000 10000 100000 RBE- BASE RESISTANCE (k ) (c) 2005 Fairchild Semiconductor Corporation 10 100 1000 10000 100000 RBE- BASE RESISTANCE (k ) Page 8 of 15 6/15/05 GENERAL PURPOSE 6-PIN PHOTOTRANSISTOR OPTOCOUPLERS 4N25 4N37 4N26 H11A1 4N27 H11A2 4N28 H11A3 4N35 H11A4 4N36 H11A5 Fig. 19 Dark Current vs. Ambient Temperature 10000 ICEO - COLLECTOR -EMITTER DARK CURRENT (nA) VCE = 10 V TA = 25C 1000 100 10 1 0.1 0.01 0.001 0 20 40 60 80 100 TA - AMBIENT TEMPERATURE (C) TEST CIRCUIT WAVE FORMS VCC = 10V INPUT PULSE IC IF INPUT RL 10% OUTPUT OUTPUT PULSE 90% RBE tr ton tf toff Adjust IF to produce IC = 2 mA Figure 20. Switching Time Test Circuit and Waveforms (c) 2005 Fairchild Semiconductor Corporation Page 9 of 15 6/15/05 GENERAL PURPOSE 6-PIN PHOTOTRANSISTOR OPTOCOUPLERS 4N25 4N37 4N26 H11A1 4N27 H11A2 4N28 H11A3 4N35 H11A4 4N36 H11A5 Black Package (No -M Suffix) Package Dimensions (Through Hole) Package Dimensions (Surface Mount) PIN 1 ID. 0.350 (8.89) 0.320 (8.13) 0.270 (6.86) 0.240 (6.10) Pin 1 ID 0.390 (9.90) 0.332 (8.43) 0.350 (8.89) 0.330 (8.38) 0.070 (1.78) 0.045 (1.14) 0.070 (1.77) 0.040 (1.02) Seating Plane SEATING PLANE 0.260 (6.60) 0.240 (6.10) 0.200 (5.08) 0.115 (2.92) 0.200 (5.08) 0.115 (2.93) 0.020 (0.51) MIN 0.154 (3.90) 0.100 (2.54) 0.320 (8.13) 0.014 (0.36) 0.010 (0.25) 0.012 (0.30) 0.008 (0.20) 0.016 (0.40) 0.008 (0.20) 0.022 (0.56) 0.016 (0.41) 0 to 15 0.300 (7.62) TYP 0.025 (0.63) 0.020 (0.51) 0.100 (2.54) TYP 0.100 [2.54] 0.035 (0.88) 0.012 (0.30) 0.020 (0.50) 0.016 (0.41) Package Dimensions (0.4" Lead Spacing) Recommended Pad Layout for Surface Mount Leadform PIN 1 ID 0.070 (1.78) 0.270 (6.86) 0.240 (6.10) 0.060 (1.52) 0.350 (8.89) 0.330 (8.38) SEATING PLANE 0.415 (10.54) 0.100 (2.54) 0.070 (1.78) 0.045 (1.14) 0.295 (7.49) 0.030 (0.76) 0.200 (5.08) 0.135 (3.43) 0.154 (3.90) 0.100 (2.54) 0.004 (0.10) MIN 0.016 (0.40) 0.008 (0.20) 0 to 15 0.022 (0.56) 0.016 (0.41) 0.100 (2.54) TYP 0.400 (10.16) TYP NOTE All dimensions are in inches (millimeters) (c) 2005 Fairchild Semiconductor Corporation Page 10 of 15 6/15/05 GENERAL PURPOSE 6-PIN PHOTOTRANSISTOR OPTOCOUPLERS 4N25 4N37 4N26 H11A1 4N27 H11A2 4N28 H11A3 4N35 H11A4 4N36 H11A5 White Package (-M Suffix) Package Dimensions (Through Hole) Package Dimensions (Surface Mount) 0.350 (8.89) 0.320 (8.13) 0.350 (8.89) 0.320 (8.13) PIN 1 ID Pin 1 ID 0.260 (6.60) 0.240 (6.10) 0.070 (1.77) 0.040 (1.02) 0.390 (9.90) 0.332 (8.43) 0.070 (1.77) 0.040 (1.02) SEATING PLANE SEATING PLANE 0.260 (6.60) 0.240 (6.10) 0.320 (8.13) 0.014 (0.36) 0.010 (0.25) 0.200 (5.08) 0.115 (2.93) 0.320 (8.13) 0.014 (0.36) 0.010 (0.25) 0.200 (5.08) 0.115 (2.93) 0.012 (0.30) 0.008 (0.20) 0.025 (0.63) 0.020 (0.51) 0.100 (2.54) 0.015 (0.38) 0.020 (0.50) 0.016 (0.41) 0.100 (2.54) 0.100 [2.54] 0.035 (0.88) 0.006 (0.16) 0.020 (0.50) 0.016 (0.41) 15 0.012 (0.30) Package Dimensions (0.4" Lead Spacing) Recommended Pad Layout for Surface Mount Leadform 0.350 (8.89) 0.320 (8.13) PIN 1 ID 0.070 (1.78) 0.260 (6.60) 0.240 (6.10) 0.060 (1.52) SEATING PLANE 0.070 (1.77) 0.040 (1.02) 0.014 (0.36) 0.010 (0.25) 0.425 (10.79) 0.100 (2.54) 0.305 (7.75) 0.030 (0.76) 0.200 (5.08) 0.115 (2.93) 0.100 (2.54) 0.015 (0.38) 0.020 (0.50) 0.016 (0.41) 0.100 [2.54] 0.012 (0.30) 0.008 (0.21) 0.425 (10.80) 0.400 (10.16) NOTE All dimensions are in inches (millimeters) (c) 2005 Fairchild Semiconductor Corporation Page 11 of 15 6/15/05 GENERAL PURPOSE 6-PIN PHOTOTRANSISTOR OPTOCOUPLERS 4N25 4N37 4N26 H11A1 4N27 H11A2 4N28 H11A3 4N35 H11A4 4N36 H11A5 ORDERING INFORMATION Order Entry Identifier Black Package (No Suffix) White Package (-M Suffix) Option .S S .SD SR2 .W T 0.4" Lead Spacing VDE 0884 Surface Mount Lead Bend Surface Mount; Tape and reel .300 V .300W TV VDE 0884, 0.4" Lead Spacing .3S SV VDE 0884, Surface Mount .3SD SR2V VDE 0884, Surface Mount, Tape & Reel MARKING INFORMATION 1 3 4N25 2 V XX YY K 6 1 V 5 4 3 Black Package, No Suffix 4N25 2 X YY Q 6 4 5 White Package, -M Suffix Definitions 1 Fairchild logo 2 Device number 3 VDE mark (Note: Only appears on parts ordered with VDE option - See order entry table) 4 One or two digit year code * Two digits for black package parts, e.g., `03' * One digit for white package parts, e.g., `3' 5 Two digit work week ranging from `01' to `53' 6 Assembly package code *Note - Parts built in the white package (M suffix) that do not have the `V' option (see definition 3 above) that are marked with date code `325' or earlier are marked in the portrait format. (c) 2005 Fairchild Semiconductor Corporation Page 12 of 15 6/15/05 GENERAL PURPOSE 6-PIN PHOTOTRANSISTOR OPTOCOUPLERS 4N25 4N37 4N26 H11A1 4N27 H11A2 4N28 H11A3 4N35 H11A4 4N36 H11A5 QT Carrier Tape Specifications (Black Package, No Suffix) 12.0 0.1 4.85 0.20 0.30 0.05 4.0 0.1 4.0 0.1 O1.55 0.05 1.75 0.10 7.5 0.1 13.2 0.2 9.55 0.20 0.1 MAX 10.30 0.20 16.0 0.3 O1.6 0.1 User Direction of Feed QT Carrier Tape Specifications (White Package, -M Suffix) 12.0 0.1 4.5 0.20 2.0 0.05 0.30 0.05 4.0 0.1 O1.5 MIN 1.75 0.10 11.5 1.0 21.0 0.1 9.1 0.20 0.1 MAX 10.1 0.20 24.0 0.3 O1.5 0.1/-0 User Direction of Feed (c) 2005 Fairchild Semiconductor Corporation Page 13 of 15 6/15/05 GENERAL PURPOSE 6-PIN PHOTOTRANSISTOR OPTOCOUPLERS 4N25 4N37 4N26 H11A1 4N27 H11A2 4N28 H11A3 4N35 H11A4 4N36 H11A5 Reflow Profile (White Package, -M Suffix) 300 280 260 240 220 200 180 160 C 140 120 100 80 60 40 20 0 260C >245C = 42 Sec Time above 183C = 90 Sec 1.822C/Sec Ramp up rate 33 Sec 0 60 120 180 270 360 Time (s) Reflow Profile (Black Package, No Suffix) Temperature (C) 300 215C, 10-30 s 250 225 C peak 200 150 Time above 183C, 60-150 sec 100 50 Ramp up = 3C/sec * Peak reflow temperature: 225C (package surface temperature) * Time of temperature higher than 183C for 60-150 seconds * One time soldering reflow is recommended 0 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 Time (Minute) (c) 2005 Fairchild Semiconductor Corporation Page 14 of 15 6/15/05 GENERAL PURPOSE 6-PIN PHOTOTRANSISTOR OPTOCOUPLERS 4N25 4N37 4N26 H11A1 4N27 H11A2 4N28 H11A3 4N35 H11A4 4N36 H11A5 DISCLAIMER FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS. LIFE SUPPORT POLICY FAIRCHILD'S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and (c) whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury of the user. (c) 2005 Fairchild Semiconductor Corporation 2. A critical component in any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. Page 15 of 15 6/15/05