BETAElectrical terminals4 LED + phototransistor
Phototransistor optocoupler
PC817 Specifications
Review PC817 electrical specifications, operating conditions and package details.
Package view
Key specifications
The infrared emitter drives a phototransistor through light. Input current, CTR, pull-up resistance and temperature determine the output behavior.
Selected rank A CTR80–160 % · stated test conditions
Operating ambient−30–100 °C · derating applies
Isolation test5 kVrms · 1 minute
Package details
PC817X1NSZ1B · DIP-4
| Property | Details |
|---|---|
| Manufacturer | Sharp |
| Part number | PC817X1NSZ1B |
| Package | DIP-4 |
| Connections | 4 pins |
| Mounting | Through-hole |
| Lead pitch | 2.54 mm |
| Package code | DIP |
| Thermal reference | Derate LED, collector and total dissipation with ambient temperature |
Selected devices and pinout
One gain grade · two lead forms
Manufacturer specifications 6 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Through-hole part | PC817X1NSZ1B | Rank A · four-pin DIP |
| SMD part | PC817X1NIP1B | Rank A · SMT gullwing DIP, not SOP-4 |
| Pin 1 / pin 2 | Anode / cathode | Input infrared LED |
| Pin 4 / pin 3 | Collector / emitter | Output phototransistor |
| CTR for selected rank A | 80–160% | Calculated from 4–8 mA collector current at IF = 5 mA, VCE = 5 V, 25°C |
| Isolation test | 5 kVrms for 1 minute | 40–60% RH; not a continuous working-voltage rating |
No specifications match. Try a parameter name or a unit.
Confirm the complete order code. PC817 variants and manufacturers need not have identical gain or limits.
Electrical characteristics
Sharp test conditions · 25°C
Manufacturer specifications 6 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| LED forward voltage | 1.2 V typical; 1.4 V maximum | IF = 20 mA |
| LED reverse current | 10 µA maximum | VR = 4 V |
| Collector dark current | 100 nA maximum | VCE = 50 V; IF = 0 |
| Collector saturation voltage | 0.1 V typical; 0.2 V maximum | IF = 20 mA; IC = 1 mA |
| Input capacitance | 30 pF typical; 250 pF maximum | V = 0; f = 1 kHz |
| Input-output capacitance | 0.6 pF typical; 1.0 pF maximum | V = 0; f = 1 MHz |
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Forward voltage varies with current and temperature. CTR measured at VCE = 5 V does not guarantee the same transfer in saturation.
Response and loading
Load-dependent phototransistor response
Manufacturer specifications 6 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Rise time | 4 µs typical; 18 µs maximum | VCE = 2 V; IC = 2 mA; RL = 100 Ω |
| Fall time | 3 µs typical; 18 µs maximum | Same response-time test |
| Cut-off frequency | 80 kHz typical | VCE = 5 V; IC = 2 mA; RL = 100 Ω; −3 dB |
| Output pull-up | Lower resistance demands more collector current | Higher resistance increases sensitivity to leakage and capacitance |
| Deep saturation | Can slow turn-off | Account for stored charge in switching designs |
| High-speed protocols | Use a suitable logic-output isolator when needed | The 80 kHz test is not a guaranteed digital data rate |
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The example uses a 10 kΩ pull-up and therefore does not inherit the 100 Ω switching-time test results.
Isolated logic input
5 V input side · separate 3.3 V output side
Manufacturer specifications 6 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Input resistance | 750 Ω | Example assumes an approximately 1.2 V LED drop |
| Estimated LED current | 5.07 mA | (5 − 1.2) / 750 |
| Input resistor dissipation | Approximately 19.3 mW | IF² × R; 0.125 W or greater nominal rating provides margin |
| Output pull-up | 10 kΩ to +3.3 V_B | Collector pin 4 is the output node |
| Low-state pull-up current | Up to approximately 0.33 mA | 3.3 V / 10 kΩ, ignoring VCE(sat) |
| Grounds | GND_A and GND_B stay separate | No conductive link across the optocoupler |
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Illustrative low-voltage circuit: verify CTR across temperature and life, logic thresholds, drive capability and switching speed for the actual design.
Absolute maximum ratings
Stress limits at 25°C unless specified
Manufacturer specifications 7 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Continuous LED current | 50 mA | Derate with ambient temperature |
| LED reverse voltage | 6 V | Avoid reverse stress in normal operation |
| Collector-emitter voltage | 80 V | LED off |
| Emitter-collector voltage | 6 V | Reverse output polarity limit |
| Collector current | 50 mA | Also limited by power dissipation and temperature |
| LED / collector / total dissipation | 70 / 150 / 200 mW | At 25°C; derating required |
| Operating / storage temperature | −30–100°C / −55–125°C | Ambient operation / unpowered storage |
No specifications match. Try a parameter name or a unit.
These are stress limits, not recommended continuous operating targets. Isolation-system design also depends on spacing, insulation and applicable standards.
Package and PCB geometry
Same electrical numbering in both packages
Manufacturer specifications 6 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Moulded body | 6.5 × 4.6 mm nominal | 3.5 mm nominal body height |
| Lead pitch | 2.54 mm | Along each two-pin row |
| DIP footprint | 7.62 mm row spacing | TEP pattern: 1.00 mm holes and 1.80 mm pads |
| SMD footprint | 8.20 mm pad-row centres | Sharp reference pads: 2.20 × 1.70 mm |
| Pin 1 identification | Anode mark on body | Square through-hole pad / top-left SMD mark |
| Board routing | Preserve separation across the barrier | Avoid copper that bypasses the intended isolation |
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Dimensions follow Sharp’s mechanical drawings; check the ordered lead form and your fabricator’s tolerances.
Connections by function
Select a pin for its function, connection guidance and electrical notes.