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Vishay General Semiconductor - Diodes Division SMAJ120AHM3/H
- Part No.:
- SMAJ120AHM3/H
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ120AHM3/H.pdf
- Description:
- TVS DIODE 120VWM 193VC DO214AC
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
SMAJ120AHM3/H from Vishay General Semiconductor is a unidirectional surface-mount Transient Voltage Suppressor (TVS) diode in SMA (DO-214AC) package, designed to protect sensitive electronics against voltage transients induced by inductive load switching and lightning surges. It features a 120 V stand-off voltage (VWM), 133–147 V breakdown voltage (VBR) at 1 mA test current, 193 V maximum clamping voltage (VC) at 1.6 A peak pulse current (IPPM), and 400 W peak pulse power rating with 10/1000 μs waveform.
For engineers reviewing the SMAJ120AHM3/H datasheet, SMAJ120AHM3/H pinout, SMAJ120AHM3/H application, or SMAJ120AHM3/H equivalent, this device is selected for robust overvoltage protection on DC power rails and signal lines in automotive ECUs, industrial motor drives, and telecom interface circuits where AEC-Q101 qualification, low incremental surge resistance, and fast response time are critical.
Technical Context
The SMAJ120AHM3/H operates as a unidirectional avalanche diode, conducting only when reverse voltage exceeds its breakdown threshold. Its glass-passivated junction ensures stable VBR tolerance and long-term reliability under repetitive surge stress. The device is rated for 40 A peak forward surge current (IFSM) and supports operation from –55 °C to +150 °C junction temperature.
Thermal performance is defined by 120 °C/W junction-to-ambient thermal resistance (RθJA) on standard 0.2" × 0.2" copper pads, and 30 °C/W junction-to-lead (RθJL). It meets MSL Level 1 per J-STD-020 and is halogen-free, RoHS-compliant, and AEC-Q101 qualified - confirmed by HM3 suffix and /H revision code.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 120 V - maximum continuous reverse operating voltage before clamping begins; defines safe DC rail protection level. |
| VBR min/max | 133 V / 147 V at IT = 1 mA - tight 10.6% tolerance ensures predictable turn-on across production lots. |
| VC @ IPPM | 193 V at 1.6 A - clamping voltage limits transient energy delivered to downstream ICs during 10/1000 μs surge. |
| PPPM | 400 W - peak pulse power handling capability with standard 10/1000 μs waveform; derates to 300 W above 78 V. |
| ID @ VWM | 1.0 μA - ultra-low reverse leakage preserves system efficiency and minimizes standby power loss. |
| TJ max. | +150 °C - enables use in under-hood automotive environments and high-temperature industrial enclosures. |
| Package | SMA (DO-214AC) - industry-standard surface-mount outline with 5.28 mm length, 4.50 mm width, and 2.29 mm height. |
Pinout & Package
Package: SMA (DO-214AC), molded plastic case with matte tin-plated leads, compliant with J-STD-002 and JESD 22-B102 solderability standards. Polarity indicated by cathode band on unidirectional devices.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to lower-potential side of protected circuit (e.g., ground or return path); conducts during positive surge events on cathode side. |
| Cathode | Reverse-biased clamping terminal | Connected to protected line (e.g., 12 V rail or signal input); initiates avalanche breakdown when transient exceeds VBR. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive-grade reliability including temperature cycling, humidity bias, and mechanical shock testing - required for ECU and ADAS power rail protection. |
| Halogen-free & RoHS-compliant | Meets IEC 61249-2-21 and JEDEC J-STD-203 requirements - supports green manufacturing and end-of-life compliance in EU and global markets. |
| 400 W peak pulse power | Handles IEC 61000-4-5 Level 4 (4 kV) surge events on 12 V/24 V systems without degradation when mounted per recommended pad layout. |
| Fast response time < 1 ps | Clamps transients before they propagate to silicon-based ICs - critical for safeguarding CAN transceivers, microcontrollers, and sensor front-ends. |
| Low incremental surge resistance | Minimizes VC overshoot during high-di/dt events, reducing stress on downstream components compared to higher-Rsurge TVS devices. |
Applications
| Automotive Power Rail Protection | Industrial Motor Drive Control |
|---|---|
|
Use Scenario: Protecting 12 V battery-supplied microcontroller power inputs in engine control units exposed to load dump and alternator ripple. IC Role / Device Role / Timing Role: Unidirectional TVS clamping transient overvoltages on VDD rail while remaining non-conductive during normal operation. Use Value: Prevents latch-up or permanent damage to MCU and CAN transceivers during ISO 16750-2 load dump tests up to 35 V for 400 ms. |
Use Scenario: Safeguarding gate driver supply lines in 3-phase inverter modules subjected to switching-induced dv/dt coupling and back-EMF spikes. IC Role / Device Role / Timing Role: Fast-acting voltage clamp absorbing nanosecond-scale transients generated by IGBT/MOSFET commutation. Use Value: Maintains gate drive integrity and prevents false triggering or shoot-through by limiting transient excursions to ≤193 V. |
| Telecom Interface Surge Protection | Consumer Sensor Signal Line Guarding |
|
Use Scenario: Shielding RS-485 transceiver data lines in outdoor base station equipment against lightning-induced surges on long cable runs. IC Role / Device Role / Timing Role: Bidirectional-capable variant not applicable; SMAJ120AHM3/H used on DC bias rails feeding isolated RS-485 PHYs. Use Value: Ensures sustained communication uptime by surviving repeated 1 kV/0.5 kA surges per IEC 61000-4-5 without parameter shift. |
Use Scenario: Securing analog output lines of automotive cabin temperature sensors connected to HVAC control modules. IC Role / Device Role / Timing Role: Low-leakage (1.0 μA) clamping element placed between sensor output and ADC input to suppress ESD and board-level transients. Use Value: Preserves measurement accuracy by avoiding reverse-bias leakage current that would otherwise offset low-level mV-range signals. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ120AHE3/H | Same electrical specs but RoHS-compliant commercial grade (E3), not halogen-free; lacks AEC-Q101 qualification. | Approved for non-automotive industrial and consumer applications where automotive reliability certification is not mandated. | Select SMAJ120AHE3/H for cost-sensitive commercial designs without AEC-Q101 or halogen-free requirements. |
| SMCJ120A-H | Higher 1500 W PPPM rating in larger SMC (DO-214AB) package; same VWM/VBR/VC values; 5.6 mm × 7.1 mm footprint. | Used where higher surge margin is needed (e.g., primary-side AC/DC input protection), requiring PCB layout change. | Choose SMCJ120A-H when system-level surge testing exceeds 400 W capability or when thermal dissipation demands larger package area. |
Compared with SMAJ120AHE3/H, SMAJ120AHM3/H adds halogen-free construction and AEC-Q101 validation for automotive deployment; versus SMCJ120A-H, it trades surge capacity and thermal mass for space-constrained layouts where SMA footprint is mandatory.
Availability
SMAJ120AHM3/H is available at Aetrix Electronics and suitable for automotive electronic control units, industrial motor drive power supplies, and telecom infrastructure equipment requiring stable component supply with full traceability and lifecycle continuity.
Supply support for SMAJ120AHM3/H includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Vishay General Semiconductor is a global leader in discrete semiconductors, specializing in diodes, rectifiers, MOSFETs, and protection devices with emphasis on reliability, efficiency, and application-specific optimization.
The SMAJ series was engineered for high-reliability transient suppression in space-constrained, high-temperature environments - particularly targeting automotive, industrial, and telecom systems needing certified surge resilience without design compromise.
FAQ
What is the clamping voltage of the SMAJ120AHM3/H under a 10/1000 μs surge?
The SMAJ120AHM3/H exhibits a maximum clamping voltage (VC) of 193 V when subjected to its rated peak pulse current of 1.6 A with a 10/1000 μs waveform. This value is measured per Figure 1 and Table 1 in Vishay Document 88390 and defines the upper voltage limit imposed on protected circuitry during standardized surge events. The SMAJ120AHM3/H maintains this clamping performance across its qualified temperature range and after multiple surge cycles when mounted per recommended PCB pad layout.
Is the SMAJ120AHM3/H suitable for automotive applications?
Yes, the SMAJ120AHM3/H is explicitly AEC-Q101 qualified, as confirmed by its HM3 suffix and /H revision code in the ordering nomenclature. It undergoes rigorous stress testing including temperature cycling, high-temperature reverse bias, and mechanical shock - making it appropriate for under-hood and chassis-mounted automotive subsystems such as body control modules, lighting drivers, and infotainment power supplies. The SMAJ120AHM3/H meets all requirements for Grade 1 (–40 °C to +125 °C ambient) and Grade 2 (–40 °C to +150 °C ambient) applications.
How does the SMAJ120AHM3/H differ from the SMAJ120A-M3 variant?
The SMAJ120AHM3/H and SMAJ120A-M3 share identical electrical specifications and SMA package dimensions, but differ in qualification and marking: SMAJ120AHM3/H includes AEC-Q101 qualification and uses /H revision coding, whereas SMAJ120A-M3 is halogen-free and RoHS-compliant but not automotive-qualified. The "H" in SMAJ120AHM3/H denotes the AEC-Q101-compliant version within the HM3 family. Both parts use matte tin-plated leads and meet JESD 201 Class 2 whisker resistance.
What is the maximum operating temperature for the SMAJ120AHM3/H?
The SMAJ120AHM3/H has a maximum junction temperature (TJ max.) of +150 °C, enabling reliable operation in high-thermal-load environments such as engine compartments, industrial inverters, and enclosed telecom cabinets. Its thermal resistance values - RθJA = 120 °C/W (on 0.2" × 0.2" copper pads) and RθJL = 30 °C/W - allow accurate junction temperature estimation under steady-state and pulsed power conditions. Derating curves in Vishay Document 88390 confirm usable power dissipation down to –55 °C ambient.
Does the SMAJ120AHM3/H have polarity marking, and how is it identified?
Yes, the SMAJ120AHM3/H is a unidirectional TVS diode and features a visible cathode band printed on the device body - consistent with DO-214AC package conventions. This band identifies the cathode terminal, which must be connected toward the side of the circuit requiring overvoltage protection (e.g., positive rail), while the anode connects to ground or return. No marking appears on bidirectional variants, but SMAJ120AHM3/H always includes the band, confirming its unidirectional functionality and correct orientation during automated placement.
SMAJ120AHM3/H Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-214AC, SMA
- Series:
- TransZorb®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Discontinued at Digi-Key
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 120V
- Voltage - Breakdown (Min):
- 133V
- Voltage - Clamping (Max) @ Ipp:
- 193V
- Current - Peak Pulse (10/1000µs):
- 1.6A
- Power - Peak Pulse:
- 400W
- Power Line Protection:
- No
- Applications:
- Telecom
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMA)
SMAJ120AHM3/H FAQ
1.How can I place an order for SMAJ120AHM3/H through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ120AHM3/H on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for SMAJ120AHM3/H reliable?
The price and inventory of SMAJ120AHM3/H are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ120AHM3/H is usually 5 days.
3.What payment methods are accepted for SMAJ120AHM3/H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ120AHM3/H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ120AHM3/H?
SMAJ120AHM3/H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ120AHM3/H order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for SMAJ120AHM3/H?
For technical support, including SMAJ120AHM3/H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ120AHM3/H requirements.
6.How does Aetrix verify that SMAJ120AHM3/H is sourced from the original manufacturer or authorized distributors?
All SMAJ120AHM3/H products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that SMAJ120AHM3/H meets industry standards.
7.What is the process for return or replacement of SMAJ120AHM3/H?
All SMAJ120AHM3/H units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ120AHM3/H, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The SMAJ120AHM3/H part is unused and in its original packaging.
Return procedure for SMAJ120AHM3/H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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