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Vishay General Semiconductor - Diodes Division SMAJ188AHM3/H
- Part No.:
- SMAJ188AHM3/H
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ188AHM3/H.pdf
- Description:
- TVS DIODE 188VWM 328VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:3,866
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Product details
Overview
SMAJ188AHM3/H from Vishay General Semiconductor is a unidirectional transient voltage suppressor (TVS) diode designed for robust overvoltage protection of sensitive electronics. It features a 188 V stand-off voltage (VWM), 209–231 V breakdown voltage (VBR) at 1 mA, 328 A peak pulse current (IPPM) with 10/1000 μs waveform, and 400 W peak pulse power dissipation - optimized for automotive-grade ESD and surge protection in high-voltage DC lines.
For engineers reviewing the SMAJ188AHM3/H datasheet, SMAJ188AHM3/H pinout, SMAJ188AHM3/H application, or SMAJ188AHM3/H equivalent, this device is evaluated for clamping performance under lightning-induced surges, load-dump transients in 24 V/48 V vehicle systems, and industrial I/O line protection where low leakage (<1.0 μA at VWM) and AEC-Q101 qualification are mandatory.
Technical Context
This unidirectional TVS diode operates as a voltage-clamped shunt protector: when reverse voltage exceeds VBR, it avalanches to divert surge current away from downstream circuitry while maintaining VC ≤ 328 V at IPPM. Its glass-passivated junction ensures stable breakdown characteristics and low incremental surge resistance across temperature.
Designed for surface-mount assembly on SMA (DO-214AC) footprint, SMAJ188AHM3/H supports automated placement and meets J-STD-020 MSL Level 1 (peak reflow 260 °C). The HM3 suffix denotes halogen-free, RoHS-compliant construction with AEC-Q101 qualification - confirming suitability for automotive powertrain and body electronics.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 188 V - maximum continuous reverse operating voltage before clamping initiates |
| VBR min/max | 209 V / 231 V at 1 mA - tight breakdown tolerance ensures predictable turn-on in high-voltage protection zones |
| VC @ IPPM | 328 V at 328 A (10/1000 μs) - clamping voltage defines worst-case stress on protected ICs or MOSFETs |
| ID @ VWM | ≤1.0 μA - ultra-low leakage preserves signal integrity and battery life in always-on circuits |
| PPPM | 400 W - peak surge energy handling capacity for transient events per IEEE C62.35 |
| TJ max | +150 °C - extended junction temperature rating enables use in under-hood automotive environments |
| Package | SMA (DO-214AC) - industry-standard 2-pin SMD outline with 5.0 mm × 5.0 mm copper pad thermal design |
Pinout & Package
Package: SMA (DO-214AC), surface-mount, cathode-banded unidirectional configuration. Dimensions: 4.93 mm × 2.92 mm × 2.29 mm (L × W × H); matte tin-plated leads, solderable per J-STD-002.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side reference terminal | Connected to system ground or lowest potential node; completes conduction path during avalanche |
| Cathode (banded end) | High-side surge input terminal | Connected to protected line (e.g., battery feed, sensor supply); blocks VWM, conducts above VBR |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive applications including engine control units and ADAS power supplies |
| Halogen-free & RoHS-compliant (HM3) | Meets automotive environmental compliance requirements without compromising surge robustness |
| 400 W peak pulse power (10/1000 μs) | Handles ISO 7637-2 Pulse 5a (load dump) up to 120 V test level with margin |
| Low clamping ratio (VC/VBR ≈ 1.44) | Minimizes voltage overshoot during fast transients, reducing stress on downstream 300 V-rated components |
| MSL Level 1, 260 °C peak reflow | Enables single-pass lead-free reflow without delamination or parameter shift |
Applications
| Automotive Load-Dump Protection | Industrial 48 V DC Power Bus |
|---|---|
|
Use Scenario: Protecting ECUs and body controllers from alternator load-dump transients (ISO 7637-2 Pulse 5a) in 24 V/48 V vehicle architectures. IC Role / Device Role / Timing Role: Unidirectional shunt TVS placed between battery rail and upstream fuse, clamping spikes within 1 ns. Use Value: Withstands 328 A surge current and limits clamped voltage to 328 V, ensuring survival of 300 V-rated MOSFETs and gate drivers. |
Use Scenario: Safeguarding programmable logic controllers (PLCs) and motor drives connected to 48 V telecom or data center backup power buses. IC Role / Device Role / Timing Role: Primary overvoltage clamp on DC input stage, coordinated with upstream fuses and downstream DC-DC converters. Use Value: 1.0 μA leakage at 188 V VWM prevents standby power drain; AEC-Q101 qualification validates long-term reliability in harsh industrial enclosures. |
| Telecom Base Station Power Input | High-Voltage Sensor Signal Conditioning |
|
Use Scenario: Front-end protection for remote radio units (RRUs) powered via 48 V PoE++ or hybrid power feeds exposed to lightning-induced surges. IC Role / Device Role / Timing Role: First-line transient suppressor before DC-DC regulation and RF front-end bias networks. Use Value: 400 W peak power rating and 120 °C/W RθJA enable operation without heatsinking in compact outdoor enclosures. |
Use Scenario: Shielding precision analog front-ends (e.g., current-sense amplifiers, isolation amplifiers) in HV battery monitoring systems. IC Role / Device Role / Timing Role: Localized clamping at sensor supply pins to prevent latch-up or die damage from coupling transients. Use Value: Tight VBR tolerance (±5%) ensures consistent clamping onset across production lots, critical for calibrated measurement accuracy. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ188AHE3/H | RoHS-compliant but not halogen-free; lacks HM3 environmental certification | Approved for commercial automotive modules where halogen-free is not mandated by OEM spec | Select when cost sensitivity outweighs halogen-free requirement and AEC-Q101 remains essential |
| SMBJ188A-HM3 | Same VWM/VBR/VC specs but in SMB (DO-214AA) package - 20% larger footprint, 15% higher RθJA (135 °C/W) | Better suited for lower-density layouts or legacy PCBs with SMB pads; less suitable for space-constrained modules | Choose only if existing layout uses SMB pads or thermal derating allows higher junction temp rise |
Compared with SMAJ188AHM3/H, SMAJ188AHE3/H omits halogen-free compliance but retains AEC-Q101 and identical electrical specs, while SMBJ188A-HM3 trades compactness for slightly reduced thermal performance in a larger package - making SMAJ188AHM3/H optimal for next-gen automotive modules demanding both miniaturization and full environmental compliance.
Availability
SMAJ188AHM3/H is available at Aetrix Electronics and suitable for automotive electronic control units, industrial 48 V power distribution systems, and telecom base station power inputs requiring stable component supply with full traceability and lifecycle continuity.
Supply support for SMAJ188AHM3/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, and protection devices with emphasis on reliability, efficiency, and application-specific validation.
The SMAJ series was engineered specifically for high-reliability transient suppression in automotive, industrial, and telecom infrastructure - combining AEC-Q101 qualification, precise clamping, and robust surge handling in compact surface-mount packages.
FAQ
What is the clamping voltage of SMAJ188AHM3/H at its rated peak pulse current?
The SMAJ188AHM3/H has a maximum clamping voltage (VC) of 328 V when subjected to its rated peak pulse current (IPPM) of 328 A under the standard 10/1000 μs waveform. This value is measured at TA = 25 °C on specified 5.0 mm × 5.0 mm copper pads and defines the upper voltage limit imposed on protected circuitry during surge events. The SMAJ188AHM3/H maintains this clamping performance across its qualified operating temperature range.
Is SMAJ188AHM3/H suitable for automotive applications?
Yes, SMAJ188AHM3/H is AEC-Q101 qualified and explicitly designated for automotive use with the HM3 suffix indicating halogen-free, RoHS-compliant construction. It meets requirements for engine control, body electronics, and ADAS power domains where load-dump immunity, thermal stability up to +150 °C, and long-term reliability under vibration and thermal cycling are mandatory. The SMAJ188AHM3/H datasheet confirms qualification per AEC-Q101 Rev D.
How does the HM3 suffix differ from E3 or M3 in the SMAJ188A family?
The HM3 suffix on SMAJ188AHM3/H indicates halogen-free, RoHS-compliant construction with AEC-Q101 qualification. In contrast, E3 denotes RoHS-compliant only (no halogen-free or automotive qualification), and M3 adds halogen-free compliance but excludes AEC-Q101. Only HM3 and HE3 variants carry the automotive qualification; HM3 is the sole option satisfying both halogen-free and AEC-Q101 requirements. SMAJ188AHM3/H therefore fulfills strict Tier 1 automotive material declarations.
What is the maximum reverse leakage current for SMAJ188AHM3/H at its stand-off voltage?
The SMAJ188AHM3/H exhibits a maximum reverse leakage current (ID) of 1.0 μA when biased at its rated stand-off voltage (VWM) of 188 V and tested at TA = 25 °C. This ultra-low leakage ensures minimal power loss in always-on automotive modules and preserves battery runtime in infotainment and telematics systems. Leakage remains below 5 μA up to TJ = 125 °C per thermal derating curves in the official Vishay datasheet.
Can SMAJ188AHM3/H be used in bidirectional configurations?
No, SMAJ188AHM3/H is a unidirectional TVS diode, identifiable by its cathode band marking. Bidirectional operation requires the "CA" suffix (e.g., SMAJ188CA), which features symmetrical breakdown in both polarities. Using SMAJ188AHM3/H in reverse-biased configurations beyond its specified forward voltage (VF = 3.5 V at 25 A) risks permanent degradation. For AC-coupled or dual-polarity signal lines, SMAJ188CA or equivalent bidirectional variants must be selected instead of SMAJ188AHM3/H.
SMAJ188AHM3/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):
- 188V
- Voltage - Breakdown (Min):
- 209V
- Voltage - Clamping (Max) @ Ipp:
- 328V
- Current - Peak Pulse (10/1000µs):
- 910mA
- 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)
SMAJ188AHM3/H FAQ
1.How can I place an order for SMAJ188AHM3/H through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ188AHM3/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 SMAJ188AHM3/H reliable?
The price and inventory of SMAJ188AHM3/H are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ188AHM3/H is usually 5 days.
3.What payment methods are accepted for SMAJ188AHM3/H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ188AHM3/H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ188AHM3/H?
SMAJ188AHM3/H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ188AHM3/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 SMAJ188AHM3/H?
For technical support, including SMAJ188AHM3/H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ188AHM3/H requirements.
6.How does Aetrix verify that SMAJ188AHM3/H is sourced from the original manufacturer or authorized distributors?
All SMAJ188AHM3/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 SMAJ188AHM3/H meets industry standards.
7.What is the process for return or replacement of SMAJ188AHM3/H?
All SMAJ188AHM3/H units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ188AHM3/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 SMAJ188AHM3/H part is unused and in its original packaging.
Return procedure for SMAJ188AHM3/H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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