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Taiwan Semiconductor Corporation SMBJ51AH
- Part No.:
- SMBJ51AH
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ51AH.pdf
- Description:
- TVS DIODE 51VWM 82.4VC DO214AA
- Quantity:
- Payment:
- Shipping:
Inventory:5,251
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Product details
Overview
SMBJ51AH from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode in DO-214AA (SMB) package, rated for 600W peak pulse power, 51V working stand-off voltage (VWM), and 82.4V maximum clamping voltage (VC) at 7.6A peak impulse current - designed to protect automotive and industrial power rails against ISO 7637-2 Pulse 1/2a/2b/3a/3b transients.
For engineers reviewing the SMBJ51AH datasheet, SMBJ51AH pinout, SMBJ51AH application, or SMBJ51AH equivalent, key selection criteria include unidirectional polarity, AEC-Q101 qualification, 10°C/W junction-to-case thermal resistance, glass-passivated junction, and sub-1ps response time - critical for ESD and load-dump protection in 12V/24V vehicle subsystems.
Technical Context
The SMBJ51AH operates as a unidirectional avalanche diode with a precisely controlled breakdown voltage range of 56.7V to 62.7V at 1mA test current, enabling reliable clamping before downstream ICs reach destructive voltage thresholds. Its glass-passivated junction ensures stable leakage performance (<1µA at 51V) and long-term reliability under thermal cycling.
Designed for automotive-grade robustness, it meets ISO 7637-2 immunity requirements for electrical fast transients and inductive switching events, with a 150°C maximum junction temperature and JESD201 Class 2 whisker resistance - supporting deployment in engine control units, body electronics, and ADAS sensor interfaces without derating at 85°C ambient.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 51 V - Maximum continuous reverse operating voltage before clamping initiates; sets safe margin above 12V/24V nominal rail. |
| VBR min/max | 56.7 V / 62.7 V - Breakdown occurs within this range at 1 mA; defines turn-on threshold consistency for system-level surge coordination. |
| VC @ IPP | 82.4 V at 7.6 A - Clamped voltage during 10/1000µs surge; limits stress on protected 60V-rated MOSFETs or CAN transceivers. |
| PPK | 600 W - Peak pulse power handling per 10/1000µs waveform; supports single-event load dump per ISO 7637-2 Pulse 5a. |
| ID @ VWM | <1 µA - Reverse leakage at 51 V; negligible power loss and signal integrity impact in always-on monitoring circuits. |
| RθJC | 10 °C/W - Junction-to-case thermal resistance; enables direct heatsinking via PCB copper pour for sustained surge duty cycles. |
Pinout & Package
DO-214AA (SMB) surface-mount package with cathode band marking; matte tin-plated leads compliant with J-STD-002 solderability and JESD201 Class 2 whisker resistance. Weight: 0.090 g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side reference node | Connected to ground or low-impedance return path; establishes clamping reference for unidirectional operation. |
| Cathode | Protected line input | Connected to power rail (e.g., battery feed); conducts avalanche current during overvoltage to shunt energy to ground. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive underhood applications including temperature cycling, mechanical shock, and humidity testing per JESD47. |
| Glass-passivated junction | Eliminates surface contamination sensitivity and improves long-term VBR stability across 15-year vehicle lifetimes. |
| Fast response time <1 ps | Clamps ESD events before propagation into sensitive analog front-ends or microcontroller I/O pins. |
| ISO 7637-2 compliance | Withstands Pulse 1 (inductive load dump), Pulse 2a/2b (switching transients), and Pulse 3a/3b (line impedance coupled noise) without degradation. |
| Moisture sensitivity level 1 | Zero bake requirement prior to reflow; compatible with standard SMT assembly lines without floor-life constraints. |
Applications
| Automotive Power Rail Protection | Industrial Sensor Interface Protection |
|---|---|
Use Scenario: 12V battery-fed infotainment head unit exposed to alternator load dump and jump-start surges. IC Role / Device Role / Timing Role: Unidirectional TVS placed between battery input and DC-DC converter input stage. Use Value: Limits transient voltage to ≤82.4V, protecting 60V-input buck controllers and preventing latch-up in PMICs. | Use Scenario: 4–20mA current-loop sensor node in factory automation subject to cable ESD and motor drive coupling. IC Role / Device Role / Timing Role: TVS mounted at connector entry point, shunting fast transients before signal conditioning op-amps. Use Value: Sub-1ps response prevents overshoot-induced offset drift in precision ADC references and maintains <1µA leakage at 24V supply. |
| LED Lighting Driver Protection | Automotive CAN Transceiver Protection |
Use Scenario: Constant-current LED driver in exterior lighting subjected to ISO 7637-2 Pulse 2b during relay switching. IC Role / Device Role / Timing Role: TVS placed across input capacitor to clamp inductive kickback from nearby solenoids. Use Value: 600W rating absorbs 100ms pulses without thermal runaway; 10°C/W RθJC allows PCB copper to dissipate residual heat. | Use Scenario: CAN FD transceiver in gateway module exposed to ESD and conducted transients on vehicle bus lines. IC Role / Device Role / Timing Role: Unidirectional TVS on VCC rail upstream of transceiver LDO, referenced to local ground plane. Use Value: 51V VWM provides margin above 45V CAN bus fault tolerance while clamping below 85V absolute max rating of transceiver supply pins. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Littelfuse SMAJ51A | Same DO-214AC (SMA) package; 84.5V VC @ 7.5A; 12°C/W RθJA; no AEC-Q101 listing. | Lower power density due to larger thermal resistance; suitable for non-automotive industrial use only. | Select when cost sensitivity outweighs automotive qualification and thermal performance requirements. |
| ON Semiconductor 1.5SMC51A | DO-214AB (SMC) package; 85.0V VC @ 7.0A; 1000W PPK; RoHS-compliant but not AEC-Q101 qualified. | Higher surge capacity but larger footprint; requires PCB layout revision and higher mounting force. | Choose for legacy designs needing higher PPK margin where space permits and automotive qualification is not mandated. |
Compared with SMAJ51A and 1.5SMC51A, SMBJ51AH delivers superior automotive readiness (AEC-Q101), tighter VBR tolerance (±5.5% vs ±6.5%), and optimized thermal performance (10°C/W RθJC) in the compact DO-214AA footprint - making it the preferred choice for space-constrained, thermally demanding vehicle ECUs.
Availability
SMBJ51AH is available at Aetrix Electronics and suitable for automotive power rail protection, industrial sensor interface hardening, LED lighting driver surge suppression, and CAN transceiver VCC rail safeguarding requiring stable component supply across multi-year production programs.
Supply support for SMBJ51AH 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
Taiwan Semiconductor Corporation (TSC) is a vertically integrated analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, specializing in high-reliability protection devices, rectifiers, and TVS diodes for automotive and industrial markets.
The SMBJH series was developed specifically to meet AEC-Q101 and ISO 7637-2 requirements for unidirectional transient suppression in 12V/24V automotive subsystems - balancing clamping precision, thermal robustness, and SMT manufacturability.
FAQ
What is the breakdown voltage range of SMBJ51AH?
The SMBJ51AH has a guaranteed breakdown voltage (VBR) range of 56.7 V to 62.7 V at 1 mA test current, measured per ANSI/IEEE C62.35. This tight tolerance ensures consistent clamping behavior across production lots and supports coordinated surge protection design with downstream 60V-rated components.
Is SMBJ51AH suitable for bidirectional transient protection?
No, SMBJ51AH is a unidirectional TVS diode intended for DC power rail protection with defined anode-cathode polarity. For bidirectional applications such as data line protection, the SMBJ51AH must be replaced with the bipolar SMBJ51CAH variant, which features symmetrical clamping in both directions and different marking (e.g., "MZ" for unidirectional vs "MZB" for bipolar).
Does SMBJ51AH meet automotive qualification standards?
Yes, SMBJ51AH is AEC-Q101 qualified and tested per JESD22-A108 for temperature cycling, JESD22-A110 for highly accelerated stress testing, and JESD22-A114 for ESD - confirming suitability for under-hood automotive applications including engine control, body electronics, and ADAS modules.
What is the maximum clamping voltage of SMBJ51AH during a surge event?
The SMBJ51AH clamps to a maximum of 82.4 V when subjected to its rated 7.6 A peak impulse current (IPP) under the standardized 10/1000 µs waveform. This value is specified in the Electrical Specifications table and verified per Figure 3 in the official Taiwan Semiconductor datasheet Version A2102.
How does SMBJ51AH compare to SMBJ51H in terms of electrical performance?
SMBJ51AH offers a tighter breakdown voltage range (56.7–62.7 V) versus SMBJ51H (56.7–69.3 V), lower clamping voltage (82.4 V vs 91.1 V at rated IPP), and improved leakage control - resulting in more precise overvoltage protection and reduced stress on downstream circuitry in safety-critical automotive systems.
SMBJ51AH Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- DO-214AA, SMB
- Series:
- SMBJH
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 51V
- Voltage - Breakdown (Min):
- 56.7V
- Voltage - Clamping (Max) @ Ipp:
- 82.4V
- Current - Peak Pulse (10/1000µs):
- 7.6A
- Power - Peak Pulse:
- 600W
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AA (SMB)
SMBJ51AH FAQ
1.How can I place an order for SMBJ51AH through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ51AH 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 SMBJ51AH reliable?
The price and inventory of SMBJ51AH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBJ51AH is usually 5 days.
3.What payment methods are accepted for SMBJ51AH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ51AH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ51AH?
SMBJ51AH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ51AH 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 SMBJ51AH?
For technical support, including SMBJ51AH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ51AH requirements.
6.How does Aetrix verify that SMBJ51AH is sourced from the original manufacturer or authorized distributors?
All SMBJ51AH 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 SMBJ51AH meets industry standards.
7.What is the process for return or replacement of SMBJ51AH?
All SMBJ51AH units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ51AH, 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 SMBJ51AH part is unused and in its original packaging.
Return procedure for SMBJ51AH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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