BETAOutput blocking400 V peak · absolute
Random-phase optotriac driver
MOC3021 Specifications
Review MOC3021 electrical specifications, operating conditions and package details.
Package view
Key specifications
The LED activates a bilateral output path. A larger power triac normally handles the final load; the optocoupler supplies its trigger.
LED trigger max.15 mA · specified conditions
Ambient range−40–85 °C
Isolation test4.17 kVrms · one minute
Package details
MOC3021M · DIP-6
| Property | Details |
|---|---|
| Manufacturer | onsemi |
| Part number | MOC3021M |
| Package | DIP-6 |
| Connections | 6 pins |
| Mounting | Through-hole |
| Lead pitch | 2.54 mm |
| Package code | 646BX |
| Thermal reference | Apply separate input, detector and total package power limits. |
Device and pin connections
Selected onsemi family
Manufacturer specifications 5 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Through-hole / surface-mount | MOC3021M / MOC3021SR2M | 646BX / formed 646BY |
| Input | 1 anode · 2 cathode | Current limiting required |
| Output | Main terminals 4 and 6 | Bilateral triac-driver output |
| Leave open | Pin 3 NC · pin 5 substrate | Never use pin 5 as a wiring junction |
| Trigger type | Random-phase | No built-in zero-cross detector |
No specifications match. Try a parameter name or a unit.
Read the selected manufacturer’s variant rather than assuming all similar part names match.
Absolute maximum ratings
Ambient 25°C unless noted
Manufacturer specifications 6 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Emitter continuous / reverse | 60 mA / 3 V | Separate stress limits |
| Output blocking | 400 V peak | Either direction |
| Output surge | 1 A, 100 µs at 120 pulses/s | Not continuous load current |
| Input / detector dissipation | 100 / 300 mW | Derate above 25°C |
| Total dissipation | 330 mW | Combined input and detector limit |
| Ambient / junction max. | −40 to +85°C / +100°C | Storage −40 to +125°C |
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A driver output must not be used as a mains power switch.
Electrical characteristics
TA 25°C; selected device
Manufacturer specifications 6 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| LED forward voltage | 1.15 V typical; 1.5 V maximum | IF 10 mA |
| LED trigger current | 15 mA maximum | Main-terminal voltage 3 V |
| Peak on-state voltage | 1.8 V typical; 3 V maximum | ITM 100 mA; IF at rated trigger |
| Holding current | 100 µA typical | Either direction |
| Off-state leakage | 10 nA typical; 100 nA maximum | Rated blocking voltage; input off |
| Static dV/dt | 1000 V/µs minimum | Input off; specified rated-voltage test |
No specifications match. Try a parameter name or a unit.
The low-current demonstration uses an explicit drop assumption.
Isolation and mounting
Device certification does not certify the assembled board
Manufacturer specifications 6 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Input-output dielectric test | 4170 Vrms · 1 minute | Test condition, not continuous working voltage |
| External creepage / clearance | ≥7 mm / ≥7 mm | Selected standard package; check installed board |
| Body | 8.51 × 6.35 mm nominal | 2.54 mm pitch; 3.40 mm nominal mould height |
| DIP footprint | 7.62 mm rows | Original 1 mm holes, 1.8 mm pads |
| SMD recommended lands | 1.525 × 1.78 mm | 9.015 mm rows; 10.54 mm outer span |
| Isolation layout | Keep both domains separate | Slots, copper, contamination and enclosure affect the system |
No specifications match. Try a parameter name or a unit.
Use the relevant safety approval option and complete system insulation design.
Isolated low-current AC demonstration
Buffered input and separate isolated output source
Manufacturer specifications 7 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Input source / resistor | 5 V_A / 220 Ω | Input switch or buffer must source the LED current |
| Nominal LED current | 17.50 mA | Assumed VF 1.15 V |
| At 1.5 V LED drop | 15.91 mA | Nominal supply/resistor only; temperature and tolerance remain |
| Output source / load | 12 V RMS isolated / 2.2 kΩ | Resistor ≥0.25 W |
| Approximate peak load | 6.90 mA | (12√2−1.8)/2200; assumed output drop |
| Resistor power upper bound | 65.5 mW | 12²/2200; neglects device drop |
| Returns | GND_A isolated from AC_B | No wire crosses the barrier |
No specifications match. Try a parameter name or a unit.
Calculated teaching values, not a measured switching waveform.
Connections by function
Select a pin for its function, connection guidance and electrical notes.