MOC3021S-TA1-A - 400V Random-Phase TRIAC Optocoupler SMD-6
부품 번호: MOC3021S-TA1-A ✓ 활성| 수량 | 단가 | 합계 |
|---|---|---|
| 1 | $0.5 | $0.50 |
| 10 | $0.39 | $3.90 |
| 100 | $0.27 | $27.00 |
| 500 | $0.2 | $100.00 |
| 1,000 | $0.15 | $150.00 |
| 5,000 | $0.11 | $550.00 |
MOC3021S-TA1-A 개요
A TRIAC-driver optoisolator is an optocoupler whose output stage is a photo-triggered bilateral thyristor (TRIAC), used to bridge low-voltage logic and a mains- or AC-line-driven TRIAC while providing galvanic isolation. In the component taxonomy, MOC3021S-TA1-A belongs to the optocoupler family, then to TRIAC/SCR-output optoisolators, then to signal/power isolation devices, and finally to discrete semiconductors / isolation components.
Key features include random-phase triggering (no zero-crossing detection), an input forward current (IF) of typically 10-15 mA for guaranteed trigger, a peak off-state voltage of 400 V minimum, a holding current (IH) of about 100 uA, and a 6-pin SMD footprint that supports automated assembly. The non-zero-crossing behavior means it can trigger at any point on the AC sinusoid, making it well suited to phase-angle control circuits such as lamp dimmers and motor-speed controllers.
Optically, the device pairs a high-efficiency GaAs IR LED with a photosensitive TRIAC chip mounted on a ceramic isolation substrate inside a clear epoxy body. The 5000 Vrms isolation barrier (Viso function) exceeds IEC 60747-5-2-style reinforced isolation requirements for line-voltage interface circuits, and the minimum 100 V/us dV/dt ensures the output TRIAC will not latch on falsely due to fast AC-line transients.
Typical applications include solid-state relay (SSR) front-ends, AC lamp dimmers, small AC motor drivers, solenoid drivers, and interface circuits for microcontrollers driving line-voltage TRIACs. Designers choose this part when they need a non-zero-crossing (random-phase) trigger so phase-angle modulation becomes possible.
When designing with this part, place a buffer resistor and snubber network across the output TRIAC, and remember that this part triggers at any phase angle - it does not wait for the next zero-cross. For zero-crossing loads, choose a MOC3041/MOC3043 instead. The SMD gull-wing package requires careful solder-pad design for clean reflow.
This synthesis integrates distributor pricing, drop-in alternatives, and practical design notes - information not found directly in the manufacturer datasheet.
드롭인 대체품: MOC3021S-TA1-A — 동일 패키지, 핀 호환. PCB 재작업이 필요한 다른 패키지 부품은 제외됩니다.
빠른 비교 도구 — 나란히 비교할 대체 부품을 선택하십시오:
MOC3020S-TA1
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
MOC3022S-TA1
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
MOC3023S-TA1
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
MOC3021SM
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
VO3021
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
MOC3021S-TA1-A 사양
| Manufacturer | Lite-On Technology |
| Part Number | MOC3021S-TA1-A |
| 출력 유형 | Triac (non-zero-cross / random phase) |
| Number of Channels | 1 |
| Input-to-Output Isolation Voltage (Viso) | 5000 Vrms (min) |
| Repetitive Peak Off-State Voltage (VDRM) | 400 V (min) |
| Critical Rate of Rise of Off-State Voltage (dV/dt) | 100 V/us (min) |
| Input Forward Current (IF, trigger) | 10 mA (typ), 15 mA (max rated) |
| Holding Current (IH) | 100 uA (typ) |
| 패키지 | 6-SMD, Gull-Wing (DIP-6 SMD) |
| 실장 유형 | Surface Mount |
| 동작 온도 | -40C to +100C |
| MSL 레벨 | 1 |
| RoHS 상태 | Compliant |
| Tape & Reel Orientation | TA-1 (AEC-Q-style tape orientation) |
MOC3021S-TA1-A 핀 구성
| 핀 1 | LED Anode (+) — Anode of the input infrared-emitting diode |
| 핀 2 | LED Cathode (-) — Cathode of the input infrared-emitting diode |
| 핀 3 | NC — Not connected (per datasheet) |
| 핀 4 | MT1 — Output photo-TRIAC main terminal 1 |
| 핀 5 | NC — Not connected (per datasheet, substrate tied to MT1 internally) |
| 핀 6 | MT2 — Output photo-TRIAC main terminal 2 |
일반적인 애플리케이션
MOC3021S-TA1-A 적합 용도: 6 애플리케이션s: Solid-State Relay (SSR) Front-End, AC Lamp Dimmer (Phase-Angle Control), Small AC Motor Speed Controller, Solenoid and Valve Driver, Microcontroller AC Line Interface, Temperature / Heater Power Regulator.
Solid-State Relay (SSR) Front-End
The MOC3021S-TA1-A's 5000 Vrms isolation barrier and 400 V VDRM photo-TRIAC output make it the canonical front-end for solid-state relays switching 120-240 VAC loads. The LED input (IF ~10-15 mA) is driven directly from microcontroller GPIO through a current-limit resistor, while the output photo-TRIAC gates an external power TRIAC (e.g., BTA16) for the actual load switching. The random-phase trigger permits zero-cross or phase-angle SSR topologies, with dV/dt >=100 V/us suppressing false triggering on noisy mains.
추천
AC Lamp Dimmer (Phase-Angle Control)
For incandescent or resistive AC lamp dimmers, the MOC3021S-TA1-A is fired by a microcontroller timed to a zero-cross detector; because it is random-phase (non-zero-cross), it can trigger the external TRIAC at any phase angle on the AC sinusoid, enabling phase-angle modulation of lamp brightness. The 400 V VDRM comfortably covers 230 VAC peak plus margin, and 5000 Vrms isolation lets the low-voltage logic side touch mains safely. The holding current (~100 uA typ) means incandescent lamps stay latched; small LED loads may need a bleed resistor.
추천
Small AC Motor Speed Controller
The MOC3021S-TA1-A is used to gate an external power TRIAC driving small universal or shaded-pole AC motors (fans, pumps, small tools). Phase-angle control through this optocoupler varies RMS voltage across the motor, giving variable speed. The 5000 Vrms isolation protects low-voltage control electronics from inductive kickback, and the 100 V/us dV/dt minimum plus an external snubber (R-C across MT1-MT2) handles inductive load transients reliably.
추천
Solenoid and Valve Driver
Industrial solenoid and AC-line valve drivers use the MOC3021S-TA1-A as the isolating gate driver between a 24 V logic controller and the 120-230 VAC solenoid coil. The 5000 Vrms isolation meets reinforced isolation requirements for industrial environments, and the random-phase trigger permits either on/off switching or pulsed-PWM-like phase-angle control for proportional solenoid valves. The MSL-1 rating simplifies high-volume reflow assembly.
추천
Microcontroller AC Line Interface
Any 5 V or 3.3 V microcontroller driving an AC line load benefits from the MOC3021S-TA1-A's galvanic isolation. The IR LED input (pin 1-2) draws ~10 mA through a current-limit resistor from GPIO; the output photo-TRIAC (pins 4-6) drives the gate of an external power TRIAC through a gate resistor. This isolation topology is industry-standard for safe line-voltage interfaces in IoT, smart-home, and appliance control boards.
추천
Temperature / Heater Power Regulator
Closed-loop AC heater power regulators use the MOC3021S-TA1-A to phase-angle-modulate the AC mains feeding a resistive heating element, proportional to a temperature sensor's PID output. The 400 V VDRM covers 230 VAC peak, and 5000 Vrms isolation separates the safety-critical mains wiring from the low-voltage sensor and microcontroller. The random-phase behavior is essential here - a zero-cross optocoupler could not deliver proportional heating.
추천
추천 제품 요약
엔지니어링 참조 데이터: MOC3021S-TA1-A — 비교, 설계 지침 및 규정 준수 정보.
선택 가이드
대체품과의 비교
| 파라미터 | 이 제품 | MOC3020S-TA1 | MOC3022S-TA1 | MOC3023S-TA1 | MOC3021SM | VO3021 |
|---|---|---|---|---|---|---|
| Brand | Lite-On | Lite-On | Lite-On | Lite-On | onsemi | Vishay Intertechnology |
| Package | 6-SMD, Gull-Wing | 6-SMD, Gull-Wing | 6-SMD, Gull-Wing | 6-SMD, Gull-Wing | 6-SMD, Gull-Wing | 6-SMD, Gull-Wing |
| VDRM (Peak Off-State Voltage) | 400 V (min) | 400 V (min) | 400 V (min) | 400 V (min) | 400 V (min) | 400 V (min) |
| Viso (Isolation Voltage) | 5000 Vrms | 5000 Vrms | 5000 Vrms | 5000 Vrms | 5300 Vrms (typ) | 5300 Vrms (typ) |
| Trigger Type | Random Phase (Non-Zero-Cross) | Random Phase | Random Phase | Random Phase | Random Phase | Random Phase |
| Trigger IF (typ) | 10 mA | 30 mA (max) | 10 mA (max) | 5 mA (max) | 15 mA (max) | 10 mA (typ) |
| dV/dt (min) | 100 V/us | 100 V/us | 100 V/us | 100 V/us | 100 V/us | 100 V/us |
| RoHS / Lead-Free | Yes | Yes | Yes | Yes | Yes | Yes |
주요 차별점
- Random-phase trigger supports phase-angle control circuits (lamp dimmers, motor speed, proportional solenoids) (vs MOC3041 (zero-cross optocoupler))
- Single Lite-On part family covering four IF trigger-current grades (MOC3020/3021/3022/3023) for design flexibility (vs onsemi MOC3021SM)
- MSL 1 rating simplifies reflow production (no dry-pack bag required) (vs Vishay VO3021)
설계 노트
Always size the input LED current-limit resistor so that IF stays between the trigger-maximum (typically 15 mA) and the trigger-minimum (typically 5-10 mA) for the specific family member. For MOC3021S-TA1-A at 5 V GPIO, a 330 ohm resistor gives ~11 mA IF (5 V - 1.2 V forward drop) / 330 = 11.5 mA. Too low an IF will fail to trigger the photo-TRIAC; too high an IF will accelerate LED aging and may exceed absolute maximum.
Maintain at least the datasheet-recommended creepage and clearance between the input-side traces (pins 1-2) and the output-side traces (pins 4-6) on the PCB. Even with 5000 Vrms internal isolation, a PCB surface arc would defeat the isolation. Keep any external snubber network compact and located within 5 mm of MT1-MT2 pins. Add a TVS or MOV across the mains side for transient protection beyond the 100 V/us dV/dt rating.
The MOC3021S-TA1-A output photo-TRIAC only handles a few hundred mA peak surge - it is intended to GATE an external power TRIAC (e.g., BTA08, BTA16, BTA25), NOT to switch the AC load directly. Driving the load through the MOC's internal TRIAC will exceed IT(RMS) ratings and destroy the part. Always use the MOC3021 as a gate-coupler, with the power TRIAC doing the actual load switching.
Estimated: at 10 mA continuous IF and 1.2 V Vf across the input LED, the input dissipates ~12 mW; output thermal is dominated by the external power TRIAC. The MOC3021S-TA1-A itself does not require a heatsink in normal gate-driver service. If used outside the datasheet's recommended operating area (e.g., driving inductive loads without a snubber), allow at least 200 mil of continuous ground copper under the package for thermal relief.
규정 준수 정보
RoHS compliant per Lite-On product page and distributor listings (DigiKey, Mouser, LCSC). MSL 1 per Lite-On datasheet. Halogen-free and conflict-minerals status not explicitly stated in verified web data - marked unknown.
