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STMicroelectronics SMBJ20CA-TR
- Part No.:
- SMBJ20CA-TR
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ20CA-TR.pdf
- Description:
- TVS DIODE 20VWM 32.4VC SMB
- Quantity:
- Payment:
- Shipping:
Inventory:25,491
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Product details
Overview
SMBJ20CA-TR from STMicroelectronics is a bidirectional transient voltage suppression (TVS) diode in SMB package, designed for robust ESD and surge protection of signal/power lines. It features 20 V standoff voltage (VRM), 32.4 V clamping voltage at 19.4 A (10/1000 µs), 600 W peak pulse power, 0.2 µA max leakage at 25 °C, and operates up to 150 °C junction temperature - deployed in industrial I/O ports, automotive body control modules, and PoE-powered Ethernet interfaces.
For engineers reviewing the SMBJ20CA-TR datasheet, SMBJ20CA-TR pinout, SMBJ20CA-TR application, or SMBJ20CA-TR equivalent, key selection criteria include bidirectional clamping symmetry, low dynamic resistance (0.404 Ω), UL497B recognition (E136224), IEC 61000-4-2 level 4 compliance (30 kV contact/air), and thermal derating above 25 °C ambient.
Technical Context
This TVS diode uses planar silicon junction technology to achieve low leakage (<1 µA at 85 °C) and stable clamping performance across its full operating temperature range (−55 to +150 °C). Its bidirectional architecture ensures symmetrical voltage limiting on both polarities without external polarity biasing.
The device delivers 600 W (10/1000 µs) and 4 kW (8/20 µs) surge handling capability with fast response time (<1 ns), enabling protection against ESD per IEC 61000-4-2, EFT per IEC 61000-4-4 level 4 (4 kV), and lightning-induced transients in low-voltage DC circuits.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Standoff Voltage (VRM) | 20 V - maximum continuous reverse working voltage before clamping initiates |
| Breakdown Voltage (VBR) | 22.2–23.4 V at 1 mA - precise threshold where avalanche conduction begins |
| Clamping Voltage (VCL) | 32.4 V at 19.4 A (10/1000 µs) - peak voltage seen by protected circuit during surge |
| Peak Pulse Power (PPP) | 600 W (10/1000 µs) - sustained surge energy dissipation capability at 25 °C ambient |
| Leakage Current (IRM) | 0.2 µA max at 20 V & 25 °C - negligible loading on high-impedance signal paths |
| Dynamic Resistance (RD) | 0.404 Ω - determines voltage rise per ampere of surge current beyond IPP |
| Junction Temperature (Tj) | −55 to +150 °C - enables deployment in under-hood automotive and industrial environments |
Pinout & Package
Package: SMB (DO-214AA), surface-mount, JEDEC-registered outline, matte tin-plated leads compliant with J-STD-020 MSL Level 1 and JESD 22-B102 E3 solderability.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (K) | Anode-side terminal (bidirectional) | Marked end of device; forms one side of symmetrical avalanche junction |
| Anode (A) | Cathode-side terminal (bidirectional) | Unmarked end; completes bidirectional conduction path with K terminal |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables single-device protection of AC-coupled or floating signal lines without polarity constraints |
| UL497B recognition (E136224) | Validated for isolated loop circuit protection in telecom and industrial safety-critical systems |
| IEC 61000-4-2 level 4 compliance | Withstands 30 kV air/contact discharge - exceeds standard requirements for industrial field equipment |
| Low TCR of clamping voltage | αT = 9.4 × 10⁻⁴ /°C - ensures predictable VCL shift over temperature for stable system-level margining |
| High-temperature reliability | Rated for 150 °C Tj operation with <1 µA leakage at 85 °C - supports compact, thermally constrained PCB layouts |
Applications
| Industrial PLC I/O Protection | Automotive Body Control Module |
|---|---|
|
Use Scenario: Protecting 24 V digital input channels in programmable logic controllers against induced surges from relay switching and motor noise. IC Role / Device Role / Timing Role: Bidirectional TVS placed between signal line and ground, clamping transients within 1 ns to prevent microcontroller GPIO latch-up. Use Value: Maintains 32.4 V clamping at 19.4 A while dissipating 600 W - sufficient to suppress 2 kV ring wave (IEC 61000-4-12) without degradation. |
Use Scenario: Safeguarding LIN bus transceivers and sensor inputs in door module ECUs exposed to load dump and jump-start events. IC Role / Device Role / Timing Role: Parallel-connected TVS on LIN data line, leveraging bidirectional symmetry to handle ±30 kV ESD per IEC 61000-4-2. Use Value: 0.2 µA leakage at 25 °C avoids signal integrity issues on 10 kΩ pull-up networks; UL497B approval satisfies OEM isolation requirements. |
| PoE-Powered Ethernet Interface | Medical Sensor Signal Conditioning |
|
Use Scenario: Protecting RJ45 Ethernet magnetics secondary windings and PHY interface pins in IEEE 802.3af/at powered devices. IC Role / Device Role / Timing Role: Bidirectional TVS on each differential pair (MDI-X), placed after common-mode choke to limit differential-mode surges. Use Value: 0.404 Ω dynamic resistance minimizes overshoot during 8/20 µs lightning surges - critical for maintaining 100BASE-TX eye diagram integrity. |
Use Scenario: Shielding analog front-end amplifiers and ADC inputs in portable patient monitors from ESD during clinical handling. IC Role / Device Role / Timing Role: Low-capacitance TVS (typ. 100 pF at 0 V) placed directly at connector entry point to shunt ESD before reaching precision op-amps. Use Value: 30 kV contact discharge immunity meets IEC 60601-1-2 ed.4 requirements; 150 °C rating supports sterilization-cycle thermal stress. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ20CA from Vishay (SMBJ20CA-E3/5BT) | Identical VRM (20 V), VBR (22.2–23.4 V), and VCL (32.4 V @ 19.4 A); slightly higher RD (0.42 Ω) | Same SMB package and UL497B recognition; lower IEC 61000-4-2 contact discharge rating (25 kV vs. 30 kV) | Preferred where cost sensitivity outweighs marginal ESD margin loss in non-critical medical or consumer interfaces |
| SMCJ20CA from STMicroelectronics (SMCJ20CA-TR) | Same electrical specs but in larger SMC (DO-214AB) package; 1500 W PPP (10/1000 µs) rating | Higher thermal mass allows sustained surge duty cycles; footprint incompatible with SMB-restricted PCBs | Select when board layout permits larger package and system requires >600 W surge headroom for repetitive transients |
Compared with Vishay's SMBJ20CA-E3/5BT, this ST part offers superior ESD robustness (30 kV vs. 25 kV) and identical clamping performance; versus ST's own SMCJ20CA-TR, it trades surge capacity for space-constrained designs where SMB footprint is mandatory.
Availability
SMBJ20CA-TR is available at Aetrix Electronics and suitable for industrial PLC I/O protection, automotive body control modules, and PoE-powered Ethernet interfaces requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for SMBJ20CA-TR 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
STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power ICs, sensors, and discrete protection devices for industrial, automotive, and consumer markets.
The SMBJ series belongs to ST's high-reliability TVS portfolio, engineered specifically for demanding transient suppression in harsh electromagnetic environments - emphasizing low leakage, tight VBR tolerance, and certified safety compliance.
FAQ
What is the difference between SMBJ20A and SMBJ20CA?
SMBJ20A is unidirectional - it clamps only in reverse bias and conducts forward like a rectifier diode; SMBJ20CA is bidirectional, providing symmetrical clamping for both positive and negative transients. The "CA" suffix denotes bidirectional configuration, essential for AC-coupled or floating signal lines where polarity is undefined.
Does SMBJ20CA-TR meet automotive AEC-Q200 requirements?
No - SMBJ20CA-TR is not AEC-Q200 qualified. It is rated for industrial and commercial applications with Tj up to 150 °C and carries UL497B recognition, but lacks the extended temperature cycling, vibration, and failure analysis testing required for automotive-grade qualification.
How does thermal derating affect SMBJ20CA-TR's 600 W rating?
The 600 W peak pulse power (10/1000 µs) applies only at Tamb = 25 °C. At 125 °C ambient, the derated PPP drops to ~350 W per Figure 3 in DS1283. This reflects reduced junction-to-ambient thermal gradient and must be accounted for in high-temperature enclosures or densely packed PCBs.
Can SMBJ20CA-TR replace P6KE20CA in an existing design?
No - P6KE20CA uses DO-15 axial package (through-hole), while SMBJ20CA-TR is SMB surface-mount. Electrical specs differ: P6KE20CA has higher VBR (22.2–24.6 V), higher VCL (36.5 V), and lower PPP (600 W same, but different test conditions). Footprint and thermal behavior are incompatible without redesign.
SMBJ20CA-TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AA, SMB
- Series:
- SMBJ, TRANSIL™
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 20V
- Voltage - Breakdown (Min):
- 22.2V
- Voltage - Clamping (Max) @ Ipp:
- 32.4V
- Current - Peak Pulse (10/1000µs):
- 19.4A
- 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:
- SMB
SMBJ20CA-TR FAQ
1.How can I place an order for SMBJ20CA-TR through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ20CA-TR 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 SMBJ20CA-TR reliable?
The price and inventory of SMBJ20CA-TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBJ20CA-TR is usually 5 days.
3.What payment methods are accepted for SMBJ20CA-TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ20CA-TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ20CA-TR?
SMBJ20CA-TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ20CA-TR 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 SMBJ20CA-TR?
For technical support, including SMBJ20CA-TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ20CA-TR requirements.
6.How does Aetrix verify that SMBJ20CA-TR is sourced from the original manufacturer or authorized distributors?
All SMBJ20CA-TR 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 SMBJ20CA-TR meets industry standards.
7.What is the process for return or replacement of SMBJ20CA-TR?
All SMBJ20CA-TR units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ20CA-TR, 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 SMBJ20CA-TR part is unused and in its original packaging.
Return procedure for SMBJ20CA-TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMBJ20CA-TR Tags
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