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Taiwan Semiconductor Corporation SMBJ70A
- Part No.:
- SMBJ70A
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ70A.pdf
- Description:
- TVS DIODE 70VWM 113VC DO214AA
- Quantity:
- Payment:
- Shipping:
Inventory:3,759
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Product details
Overview
SMBJ70A from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode designed for high-energy ESD and surge protection in DC power lines and signal paths. It features a 70 V working stand-off voltage (VWM), 77.8–86 V breakdown voltage (VBR), 113 V maximum clamping voltage (VC) at 5.5 A peak pulse current, and 600 W peak pulse power rating with a <1.0 ps response time. It is used in automotive power supply inputs and industrial control I/O interfaces to protect downstream ICs from ISO 7637-2 Pulse 1/2a/2b/3a/3b transients.
For engineers reviewing the SMBJ70A datasheet, SMBJ70A pinout, SMBJ70A application, or SMBJ70A equivalent, key selection criteria include clamping voltage margin relative to protected IC's absolute maximum rating, leakage current at operating voltage, thermal derating above 25°C ambient, and DO-214AA (SMB) package compatibility with board layout and reflow profiles.
Technical Context
The SMBJ70A operates as a unidirectional avalanche diode, conducting only during reverse overvoltage events while presenting high impedance under normal bias. Its glass-passivated junction ensures stable breakdown characteristics and low leakage (<1 µA at 70 V), and its 10 °C/W junction-to-case thermal resistance supports sustained energy dissipation in compact layouts.
It complies with ISO 7637-2 for automotive transient immunity (Pulse 1, 2a, 2b, 3a, 3b) and meets J-STD-020 moisture sensitivity level 1. The device is rated for -55°C to +150°C junction temperature and uses matte tin-plated leads compliant with J-STD-002 solderability standards.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 70 V - Maximum continuous DC or RMS voltage the device blocks without conduction |
| VBR min/max | 77.8 V / 86 V @ 1 mA - Confirmed breakdown threshold range defining turn-on consistency |
| VC @ IPP | 113 V @ 5.5 A - Clamped voltage seen by protected circuit during 10/1000 µs surge |
| PPK | 600 W - Peak non-repetitive surge power handling capability per IEC 61000-4-5 |
| ID @ VWM | <1 µA - Minimal leakage current preserving system efficiency and battery life |
| TJ max | +150 °C - Maximum junction temperature enabling operation in under-hood or enclosed industrial environments |
| RθJA | 55 °C/W - Thermal resistance from junction to ambient, critical for PCB copper area design |
Pinout & Package
Package: DO-214AA (SMB), surface-mount, single-diode configuration with cathode band marking. Dimensions conform to JEDEC DO-214AA standard; recommended pad layout provided in Taiwan Semiconductor package drawing R2104.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward current path terminal | Connected to lower-potential side (e.g., ground or return path) in unidirectional TVS configuration |
| Cathode | Avalanche conduction terminal | Connected to protected line (e.g., 12 V rail); conducts when line voltage exceeds VBR relative to anode |
Key Features
| Feature | Design Value |
|---|---|
| Fast response time | <1.0 ps - Enables suppression before sensitive ICs experience overstress during ESD or fast transients |
| Glass passivated junction | Stable VBR tolerance and low IR drift over temperature and lifetime vs. epoxy-passivated alternatives |
| ISO 7637-2 compliance | Validated performance against automotive load-dump and inductive-switching pulses without external filtering |
| Moisture sensitivity level 1 | No floor-life limitation or bake requirement prior to reflow - simplifies SMT manufacturing flow |
| Halogen-free & RoHS | Meets IEC 61249-2-21 and EU RoHS Directive - supports green electronics compliance programs |
Applications
| Automotive Power Input Protection | Industrial PLC Digital I/O Protection |
|---|---|
Use Scenario: 12 V battery-fed ECUs exposed to load dump (ISO 7637-2 Pulse 5a) and alternator ripple. IC Role / Device Role: Unidirectional TVS placed between power rail and ground to clamp surges before they reach LDOs or microcontrollers. Use Value: SMBJ70A clamps to 113 V at 5.5 A, staying well below typical 36 V input-rated PMIC absolute maximum ratings while surviving 600 W transients. | Use Scenario: 24 V digital input modules receiving signals from field sensors subject to inductive kickback. IC Role / Device Role: TVS on each input channel to absorb energy from relay coil de-energization (ISO 7637-2 Pulse 2b). Use Value: With 70 V VWM, SMBJ70A remains fully blocking during normal 24 V operation yet triggers reliably before 30 V logic interface ICs are damaged. |
| LED Driver Power Stage Protection | RS-485 Transceiver Bus Line Protection |
Use Scenario: Constant-current LED drivers powered from 48 V supplies, vulnerable to hot-swap and cable discharge events. IC Role / Device Role: Primary surge clamp on the high-side switch node or input capacitor bank. Use Value: 600 W PPK rating allows absorption of multiple 10/1000 µs surges without degradation; 113 V VC limits stress on 60 V MOSFETs and gate drivers. | Use Scenario: RS-485 transceivers connected to long outdoor cables susceptible to lightning-induced surges. IC Role / Device Role: Unidirectional TVS on A/B bus lines referenced to local ground, paired with common-mode chokes. Use Value: Low 1 µA leakage at 70 V prevents signal integrity degradation on half-duplex differential buses while providing robust 600 W transient immunity. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ70CA | Bidirectional variant; symmetric VBR (77.8–86 V) in both polarities; same VWM, VC, and PPK | Required for AC-coupled or floating-bus applications (e.g., Ethernet PHY, audio lines) where polarity reversal occurs | Select SMBJ70CA only if bidirectional clamping is needed; SMBJ70A is preferred for DC rails with defined ground reference. |
| SAC70A | Same VWM (70 V) and VC (113 V), but lower PPK (400 W); smaller DO-214AC (SMC) package with higher RθJA (65 °C/W) | Suitable for space-constrained designs with lower surge exposure (e.g., consumer USB ports), not automotive-grade transients | Choose SAC70A only when board area is critical and surge threat level is reduced; SMBJ70A provides higher reliability for industrial/automotive use. |
Compared with SMBJ70CA and SAC70A, the SMBJ70A delivers optimal balance of unidirectional clamping precision, 600 W surge capacity, and thermal performance in the industry-standard DO-214AA footprint-making it the default choice for DC power rail protection where polarity is fixed and transient severity is high.
Availability
SMBJ70A is available at Aetrix Electronics and suitable for automotive body control modules, industrial programmable logic controllers, LED lighting drivers, and RS-485 communication interfaces requiring stable component supply across extended temperature ranges and multi-year production cycles.
Supply support for SMBJ70A 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 TVS diodes, rectifiers, MOSFETs, and power management devices.
The SMBJ series was developed specifically for high-reliability transient suppression in automotive and industrial environments, emphasizing robustness to ISO 7637-2 pulses, tight VBR tolerances, and manufacturability in automated SMT lines.
FAQ
What is the maximum clamping voltage of SMBJ70A under a 10/1000 µs surge?
The SMBJ70A has a maximum clamping voltage (VC) of 113 V when subjected to a 10/1000 µs waveform at 5.5 A peak impulse current. This value is measured per IEC 61000-4-5 and ANSI/IEEE C62.35 standards and represents the highest voltage the protected circuit will experience during such a transient event. The SMBJ70A maintains this clamping performance across its full operating temperature range.
Is SMBJ70A unidirectional or bidirectional, and how is polarity identified?
SMBJ70A is a unidirectional TVS diode. Polarity is indicated by a cathode band printed on the device body, aligned with the cathode terminal. In circuit implementation, the cathode connects to the line being protected (e.g., 70 V rail), and the anode connects to ground or the lower-potential reference. Bidirectional variants carry a "C" or "CA" suffix (e.g., SMBJ70CA), which SMBJ70A does not have.
What is the leakage current specification for SMBJ70A at its working stand-off voltage?
At its 70 V working stand-off voltage (VWM), the SMBJ70A exhibits a maximum blocking leakage current (ID) of 1 µA at 25°C ambient temperature. This low leakage preserves system efficiency in battery-powered or low-power standby applications and avoids false triggering in high-impedance sensing circuits. Leakage remains below 5 µA up to +125°C per thermal derating curves.
Does SMBJ70A meet automotive transient immunity standards?
Yes, SMBJ70A is explicitly validated to meet ISO 7637-2 for automotive electrical disturbances, covering Pulse 1 (inductive load disconnect), Pulse 2a (sudden load removal), Pulse 2b (inductive switch-off), Pulse 3a (capacitive coupled noise), and Pulse 3b (battery connection bounce). This compliance is documented in Taiwan Semiconductor's SMBJ series datasheet revision R2104 and confirmed via standardized test waveforms.
What is the package type and mounting compatibility of SMBJ70A?
SMBJ70A is housed in the DO-214AA (SMB) surface-mount package, with standardized dimensions and lead finish per JEDEC MS-012. It is compatible with standard reflow soldering profiles (per J-STD-020 Level 1), uses matte tin-plated leads (J-STD-002 compliant), and requires no pre-bake due to its MSL-1 rating. The SMB footprint is widely supported in PCB design libraries and SMT assembly equipment.
SMBJ70A Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- DO-214AA, SMB
- Series:
- SMBJ
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 70V
- Voltage - Breakdown (Min):
- 77.8V
- Voltage - Clamping (Max) @ Ipp:
- 113V
- Current - Peak Pulse (10/1000µs):
- 5.3A
- Power - Peak Pulse:
- 600W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AA (SMB)
SMBJ70A FAQ
1.How can I place an order for SMBJ70A through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ70A 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 SMBJ70A reliable?
The price and inventory of SMBJ70A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBJ70A is usually 5 days.
3.What payment methods are accepted for SMBJ70A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ70A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ70A?
SMBJ70A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ70A 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 SMBJ70A?
For technical support, including SMBJ70A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ70A requirements.
6.How does Aetrix verify that SMBJ70A is sourced from the original manufacturer or authorized distributors?
All SMBJ70A 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 SMBJ70A meets industry standards.
7.What is the process for return or replacement of SMBJ70A?
All SMBJ70A units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ70A, 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 SMBJ70A part is unused and in its original packaging.
Return procedure for SMBJ70A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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