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Vishay General Semiconductor - Diodes Division SMB8J12CA-E3/5B
- Part No.:
- SMB8J12CA-E3/5B
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMB8J12CA-E3/5B.pdf
- Description:
- TVS DIODE 12VWM 19.9VC DO214AA
- Quantity:
- Payment:
- Shipping:
Inventory:3,084
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Product details
Overview
SMB8J12CA-E3/5B from Vishay General Semiconductor is a bidirectional transient voltage suppressor (TVS) diode in SMB (DO-214AA) package, designed for high-energy surge protection on signal and power lines. It features a 12 V stand-off voltage (VWM), 13.3–14.7 V breakdown voltage (VBR) at 1 mA, 19.9 V clamping voltage (VC) at 40.2 A peak pulse current (IPPM), and 800 W peak pulse power (PPPM) with 10/1000 µs waveform - deployed in automotive sensor interfaces and industrial I/O protection.
For engineers reviewing the SMB8J12CA-E3/5B datasheet, SMB8J12CA-E3/5B pinout, SMB8J12CA-E3/5B application, or SMB8J12CA-E3/5B equivalent, key selection criteria include bidirectional clamping capability, AEC-Q101 qualification, low leakage (<5 µA at VWM), MSL Level 1 moisture sensitivity, and compatibility with automated SMT placement on 0.2" × 0.2" copper pads.
Technical Context
This TVS diode operates as a voltage-clamped shunt protector: under normal conditions it presents high impedance (>1 GΩ at 12 V), then rapidly switches to low-impedance conduction when transients exceed VBR. Its glass-passivated junction ensures stable breakdown and low incremental surge resistance, critical for repeatable clamping performance across temperature (-55 °C to +150 °C).
The device meets ANSI/IEEE C62.35 surge standards and is rated for non-repetitive 10/1000 µs surges up to 40.2 A. Thermal resistance is 72 °C/W (junction-to-ambient) and 20 °C/W (junction-to-lead), enabling reliable operation on standard PCB copper land patterns without heatsinking.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 12 V - maximum continuous reverse operating voltage before significant leakage; defines safe working margin for 12 V rail protection. |
| VBR min/max | 13.3 V / 14.7 V at 1 mA - tight breakdown tolerance ensures predictable turn-on during ESD or load-switching transients. |
| VC @ IPPM | 19.9 V at 40.2 A - clamping voltage limits downstream IC stress during 800 W surge events. |
| PPPM | 800 W (10/1000 µs) - energy-handling capacity suitable for ISO 7637-2 Pulse 1/2a/3a and IEC 61000-4-5 Level 3 surges. |
| ID @ VWM | <5 µA - ultra-low leakage preserves signal integrity and battery life in always-on sensor circuits. |
| TJ max | +150 °C - supports under-hood automotive use and industrial environments with elevated ambient temperatures. |
| AEC-Q101 | Qualified - validated for automotive-grade reliability including temperature cycling, HTRB, and ESD robustness. |
Pinout & Package
Package: SMB (DO-214AA), surface-mount, bidirectional - no polarity marking; symmetrical dual-anode/dual-cathode structure.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode 1 / Anode 2 | Transient return path (bidirectional) | Both terminals function identically; either can serve as reference ground or line connection depending on PCB layout. |
| Anode 1 / Cathode 2 | Transient return path (bidirectional) | Enables symmetric clamping between any two points - ideal for differential signal line protection (e.g., CAN, RS-485). |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Protects AC-coupled or floating lines without polarity constraints - eliminates need for dual unidirectional devices. |
| AEC-Q101 qualification | Validated for automotive electronics including engine control modules, ADAS sensors, and body control units. |
| MSL Level 1 (260 °C peak) | Compatible with standard lead-free reflow profiles - no floor-life management required prior to assembly. |
| Glass-passivated junction | Ensures long-term parameter stability and low leakage drift over 15+ year service life in harsh environments. |
| Low clamping ratio (VC/VBR ≈ 1.42) | Minimizes overvoltage overshoot during fast transients - critical for protecting 12 V tolerant microcontrollers and transceivers. |
Applications
| Automotive Sensor Interface | Industrial Digital I/O Protection |
|---|---|
Use Scenario: Protecting LIN bus or analog sensor outputs (e.g., pressure, temperature) from load-dump and inductive switching transients in vehicle ECUs. IC Role / Device Role / Timing Role: Shunt-type transient suppressor placed directly at connector entry point, clamping surges before reaching MCU ADC or LIN transceiver. Use Value: Maintains signal fidelity below 20 V clamping threshold while surviving repeated 800 W pulses per ISO 7637-2. |
Use Scenario: Safeguarding PLC digital input channels against field-wiring induced surges in factory automation systems. IC Role / Device Role / Timing Role: Primary front-end protection element on 24 V DC input lines, coordinated with upstream fuse and series impedance. Use Value: Enables >100,000 surge cycles without degradation due to stable glass-passivated junction and low thermal resistance. |
| RS-485 Data Line Protection | Power Supply Rail Clamping |
Use Scenario: Bidirectional protection of half-duplex RS-485 bus lines (A/B) exposed to ESD and lightning-induced surges in building control networks. IC Role / Device Role / Timing Role: Low-capacitance (≈100 pF) TVS placed across differential pair to clamp common-mode transients without distorting data signals up to 10 Mbps. Use Value: Symmetric clamping ensures equal protection on both lines - prevents data corruption during ±15 kV contact ESD per IEC 61000-4-2. |
Use Scenario: Secondary overvoltage clamp on 12 V auxiliary power rail feeding infotainment modules or camera systems. IC Role / Device Role / Timing Role: Fast-response backup to primary DC-DC regulator OVP, limiting rail excursions during feedback loop failure or hot-swap events. Use Value: 19.9 V clamping holds rail within safe operating range of 16 V-rated LDOs and PMICs, preventing latch-up or burnout. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ12CA-E3/5B | 1000 W PPPM (unidirectional rating only); same VWM/VBR/VC but higher IPPM (50.3 A) and lower RθJA (65 °C/W). | Optimized for higher-energy unidirectional surges; not AEC-Q101 qualified in standard commercial version. | Select SMBJ12CA-E3/5B only if system requires >800 W single-polarity surge handling and automotive qualification is not mandated. |
| SMCJ12CA-E3/57T | Larger SMC (DO-214AB) package; 1500 W PPPM; identical VWM/VBR/VC specs but higher thermal mass and 3× footprint area. | Used where board space permits and higher surge endurance (e.g., telecom power entry) justifies larger size and cost. | Choose SMCJ12CA-E3/57T when design must survive repeated 1500 W surges and PCB layout accommodates 7.11 mm × 6.22 mm footprint. |
Compared with SMBJ12CA-E3/5B and SMCJ12CA-E3/57T, SMB8J12CA-E3/5B delivers optimal balance of AEC-Q101 compliance, compact SMB footprint, and 800 W bidirectional surge capability - making it the preferred choice for space-constrained automotive and industrial edge nodes.
Availability
SMB8J12CA-E3/5B is available at Aetrix Electronics and suitable for automotive sensor protection, industrial I/O conditioning, RS-485 interface hardening, and 12 V power rail clamping requiring stable component supply across production lifecycles.
Supply support for SMB8J12CA-E3/5B 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, MOSFETs, optoelectronics, and passive components with emphasis on reliability and application-specific performance.
The SMB8JxxCA family targets high-density, AEC-Q101-compliant transient suppression for automotive and industrial electronics where bidirectional clamping, low profile, and automated assembly are mandatory.
FAQ
What is the clamping voltage of SMB8J12CA-E3/5B at its rated peak pulse current?
The SMB8J12CA-E3/5B has a maximum clamping voltage (VC) of 19.9 V at 40.2 A peak pulse current (IPPM), measured with a 10/1000 µs waveform. This value defines the upper voltage limit imposed on protected circuitry during an 800 W transient event, ensuring downstream components like 12 V microcontrollers remain within safe operating margins. The SMB8J12CA-E3/5B achieves this with low incremental surge resistance and a stable glass-passivated junction.
Is SMB8J12CA-E3/5B suitable for automotive applications?
Yes, SMB8J12CA-E3/5B is AEC-Q101 qualified and specifically designed for automotive use - validated for temperature cycling, highly accelerated life testing (HALT), and ESD robustness per JESD22-A114. Its 150 °C maximum junction temperature, MSL Level 1 rating, and RoHS-compliant matte tin plating make SMB8J12CA-E3/5B appropriate for engine bay sensors, body control modules, and ADAS camera power rails.
How does SMB8J12CA-E3/5B differ from unidirectional SMBJ12A variants?
SMB8J12CA-E3/5B is bidirectional with symmetrical clamping behavior on both terminals, whereas SMBJ12A is unidirectional and requires correct cathode orientation. SMB8J12CA-E3/5B offers 800 W PPPM and 40.2 A IPPM, while SMBJ12A provides 1000 W PPPM and 50.3 A IPPM - but only in one direction. The SMB8J12CA-E3/5B also carries AEC-Q101 qualification, unlike standard SMBJ12A-E3/5B.
What is the thermal resistance of SMB8J12CA-E3/5B, and how does it affect PCB layout?
SMB8J12CA-E3/5B has a typical junction-to-ambient thermal resistance (RθJA) of 72 °C/W and junction-to-lead resistance (RθJL) of 20 °C/W. These values assume mounting on 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pads per terminal. To maintain safe operation under repeated surges, PCB layout must replicate this minimum pad area - reducing pad size increases thermal impedance and risks junction overheating beyond the 150 °C limit during SMB8J12CA-E3/5B's rated PPPM.
Does SMB8J12CA-E3/5B have polarity markings, and how is it installed?
No, SMB8J12CA-E3/5B has no polarity markings because it is a bidirectional device - both terminals are functionally identical. Installation requires no orientation check; either end may connect to line or ground. This simplifies automated placement and eliminates risk of reverse installation errors common with unidirectional TVS diodes. The SMB8J12CA-E3/5B's symmetrical construction enables flexible routing in differential or floating signal paths.
SMB8J12CA-E3/5B Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-214AA, SMB
- Series:
- TransZorb®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 12V
- Voltage - Breakdown (Min):
- 13.3V
- Voltage - Clamping (Max) @ Ipp:
- 19.9V
- Current - Peak Pulse (10/1000µs):
- 40.2A
- Power - Peak Pulse:
- 800W
- 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)
SMB8J12CA-E3/5B FAQ
1.How can I place an order for SMB8J12CA-E3/5B through Aetrix?
Please submit a Request for Quotation (RFQ) for SMB8J12CA-E3/5B 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 SMB8J12CA-E3/5B reliable?
The price and inventory of SMB8J12CA-E3/5B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMB8J12CA-E3/5B is usually 5 days.
3.What payment methods are accepted for SMB8J12CA-E3/5B?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMB8J12CA-E3/5B transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMB8J12CA-E3/5B?
SMB8J12CA-E3/5B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMB8J12CA-E3/5B 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 SMB8J12CA-E3/5B?
For technical support, including SMB8J12CA-E3/5B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMB8J12CA-E3/5B requirements.
6.How does Aetrix verify that SMB8J12CA-E3/5B is sourced from the original manufacturer or authorized distributors?
All SMB8J12CA-E3/5B 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 SMB8J12CA-E3/5B meets industry standards.
7.What is the process for return or replacement of SMB8J12CA-E3/5B?
All SMB8J12CA-E3/5B units undergo pre-shipment inspection (PSI). If there is an issue with SMB8J12CA-E3/5B, 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 SMB8J12CA-E3/5B part is unused and in its original packaging.
Return procedure for SMB8J12CA-E3/5B:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMB8J12CA-E3/5B Tags
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