My Inquiry
My Account
STMicroelectronics SMC50J40CA
- Part No.:
- SMC50J40CA
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMC50J40CA.pdf
- Description:
- 5000 W, 40 V TVS IN SMC
- Quantity:
- Payment:
- Shipping:
Inventory:1,000
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMC50J40CA from STMicroelectronics is a bidirectional transient voltage suppression (TVS) diode in SMC package, designed for IEC 61000-4-2 ESD protection (30 kV air/contact) and IEC 61000-4-4 surge immunity (4 kV level 4). It features 40 V standoff voltage (VRM), 64.5 V clamping voltage (VCL) at 78 A IPP (10/1000 µs), and 0.2 µA leakage at 25 °C - enabling robust protection in high-reliability power supply inputs and industrial communication interfaces.
For engineers reviewing the SMC50J40CA datasheet, SMC50J40CA pinout, SMC50J40CA application, or SMC50J40CA equivalent, this device is selected for high-energy surge suppression where low leakage, 175 °C junction operation, JEDEC-compliant SMC footprint, and bidirectional polarity are required - especially in DC power rails, PoE injectors, and RS-485 transceiver protection circuits.
Technical Context
This TVS diode uses planar silicon avalanche technology to achieve precise breakdown behavior and stable clamping under repetitive surges. Its bidirectional configuration provides symmetrical protection without polarity dependency, making it suitable for AC-coupled signal lines and floating DC buses.
It delivers 5000 W peak pulse power (10/1000 µs) and up to 48 kW (8/20 µs), with dynamic resistance (RD) of 68.5 mΩ and temperature coefficient αT = 10.1 × 10⁻⁴ /°C - ensuring predictable VBR and VCL drift across –55 °C to +175 °C operating junction range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Standoff Voltage (VRM) | 40 V - maximum continuous reverse working voltage before conduction begins; defines safe operating margin for 36–42 V DC systems. |
| Clamping Voltage (VCL) | 64.5 V at 78 A (10/1000 µs) - limits transient voltage seen by downstream ICs; ensures protected circuit remains below 65 V during worst-case surge. |
| Peak Pulse Power (PPP) | 5000 W (10/1000 µs) - sustains high-energy transients typical in industrial power line surges and load dump events. |
| Leakage Current (IRM) | 0.2 µA at 25 °C - negligible standby power loss and minimal impact on high-impedance sensing or battery-backed circuits. |
| Junction Temperature (Tj) | –55 °C to +175 °C - supports operation in harsh environments including automotive under-hood, industrial motor drives, and outdoor telecom equipment. |
| ESD Rating | 30 kV contact & air discharge (IEC 61000-4-2) - exceeds level 4 requirements, eliminating need for additional ESD stages in front-end protection. |
| Surge Rating | 4 kV (IEC 61000-4-4 level 4) - withstands fast-rising repetitive bursts common in AC mains coupling and relay switching noise. |
Pinout & Package
The SMC50J40CA is housed in a JEDEC-standard SMC (DO-214AB) surface-mount package with matte tin-plated leads and MSL level 1 moisture sensitivity. The bidirectional structure has no anode/cathode designation; both terminals are electrically symmetrical.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode/Cathode (Bidirectional) | Surge current path (symmetrical) | Either terminal conducts during positive or negative transients - simplifies PCB layout and eliminates polarity concerns in AC or floating DC applications. |
| Cathode Bar Marking | Visual polarity indicator (non-functional for CA) | Present per marking convention but electrically irrelevant for bidirectional type; used only for traceability and version differentiation vs. unidirectional A variants. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional ESD/surge protection | Enables single-device protection of AC signals or differential buses (e.g., RS-485, CAN FD) without external polarity management. |
| Low dynamic resistance (68.5 mΩ) | Minimizes clamping voltage rise under high-current surges, improving protection margin for sensitive 3.3 V or 5 V logic interfaces. |
| 175 °C max junction temperature | Supports placement near heat-generating components (e.g., MOSFETs, inductors) without derating, reducing thermal design overhead. |
| JEDEC SMC footprint compliance | Ensures drop-in compatibility with standard reflow processes and automated assembly lines using IPC-7531 land patterns. |
| UL94 V0 flammability rating | Meets safety-critical enclosure requirements for industrial and medical power supplies without additional flame-retardant conformal coating. |
Applications
| Industrial Power Input Protection | RS-485 Transceiver Interface |
|---|---|
|
Use Scenario: 24–48 V DC input stage of PLC I/O modules exposed to lightning-induced surges and inductive switching transients. IC Role / Device Role / Timing Role: Primary overvoltage clamp placed upstream of DC-DC converter input, absorbing energy before it reaches primary-side FETs and controller ICs. Use Value: Limits transient voltage to ≤64.5 V during 78 A surges, preventing damage to 65 V-rated input capacitors and gate drivers while maintaining system uptime. |
Use Scenario: Differential data lines of industrial RS-485 nodes installed in factory-floor machinery with long cable runs. IC Role / Device Role / Timing Role: Bidirectional TVS placed across A/B bus lines and ground, suppressing ESD and fast transients without distorting signal integrity. Use Value: Withstands 30 kV ESD strikes and 4 kV ring waves while adding <100 pF capacitance - preserving signal edge rates up to 10 Mbps. |
| PoE+ Midspan Injector | Automotive Body Control Module (BCM) |
|
Use Scenario: 4-pair PoE+ (IEEE 802.3at) injector delivering up to 30 W over CAT6 cabling in enterprise networks. IC Role / Device Role / Timing Role: Secondary-level surge protector on each powered pair, complementing primary GDT-based protection. Use Value: Clamps induced surges to <65 V within nanoseconds, protecting IEEE 802.3at PD interface controllers rated for 60 V absolute maximum. |
Use Scenario: 12 V battery-supplied lighting and sensor interface in passenger compartment BCMs subject to load dump and jump-start conditions. IC Role / Device Role / Timing Role: Bidirectional clamp on LIN or CAN FD signal lines tied to microcontroller GPIOs with 5.5 V tolerance. Use Value: Survives 175 °C ambient under hood conditions and suppresses 30 kV ESD without latch-up, meeting ISO 10605 and ISO 7637-2 requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ40CA (Bourns) | Same VRM (40 V), lower PPP (600 W), higher VCL (69.4 V at 58.1 A), SMB package (smaller footprint, lower thermal mass) | Limited to lower-energy surges; unsuitable for 5000 W IEC 61000-4-4 compliance | Select when space-constrained layouts prioritize size over surge rating - not for industrial mains-connected designs. |
| TPSMD40CA (Texas Instruments) | Same VRM (40 V), identical PPP (5000 W), slightly higher VCL (65.8 V), same SMC package, but 100 nA leakage (vs. 0.2 µA) | Lower leakage benefits ultra-low-power wake-on-LIN or battery-backed sensors; otherwise functionally interchangeable | Prefer for always-on automotive modules where sub-100 nA leakage reduces quiescent current budget impact. |
Compared with SMC50J40CA, SMBJ40CA trades surge capability for compactness, while TPSMD40CA offers tighter leakage control at equivalent power handling - making the ST part optimal for cost-sensitive, thermally demanding industrial applications requiring full 5000 W compliance.
Availability
SMC50J40CA is available at Aetrix Electronics and suitable for industrial power input protection, RS-485 interface hardening, PoE+ midspan injectors, and automotive body control modules requiring stable component supply and long-term lifecycle support.
Supply support for SMC50J40CA 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, specializing in power management, analog, MEMS, and microcontrollers for industrial, automotive, and consumer markets.
The SMC50J TVS series targets high-reliability surge protection in industrial automation and power conversion systems, emphasizing thermal robustness, JEDEC-compliant manufacturability, and full IEC/ISO compliance out-of-the-box.
FAQ
What is the maximum clamping voltage of SMC50J40CA under a 10/1000 µs surge?
The maximum clamping voltage (VCL) is 64.5 V at 78 A peak pulse current for a 10/1000 µs waveform, measured at 25 °C ambient. This value increases with junction temperature at a rate defined by αT = 10.1 × 10⁻⁴ /°C, reaching ~67.2 V at 125 °C junction.
Is SMC50J40CA compatible with lead-free reflow soldering?
Yes - it is qualified for lead-free reflow per J-STD-020 MSL level 1, with a maximum peak temperature of 245 °C and 60-second exposure above 220 °C. The matte tin plating and SMC package meet IPC/JEDEC thermal profile requirements without delamination or voiding.
How does the bidirectional configuration affect PCB layout versus unidirectional variants?
The bidirectional SMC50J40CA eliminates polarity constraints: either terminal connects to the protected line and the other to ground, removing orientation checks during placement. Unlike unidirectional A-types (e.g., SMC50J40A), no cathode bar must align with ground - reducing assembly errors and enabling symmetric routing on differential pairs.
Can SMC50J40CA be used in parallel for higher surge current handling?
No - TVS diodes exhibit parametric mismatch (VBR tolerance ±5 %, RD variation), causing current imbalance and potential thermal runaway. For >78 A surge capability, select a higher-rated single device (e.g., SMC50J48CA) or implement staged protection with GDT + TVS rather than paralleling.
SMC50J40CA Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AB, SMC
- Series:
- SMC50J
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 40V (Max)
- Voltage - Breakdown (Min):
- 44.4V
- Voltage - Clamping (Max) @ Ipp:
- 64.5V
- Current - Peak Pulse (10/1000µs):
- 78A
- Power - Peak Pulse:
- 5000W (5kW)
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMC
SMC50J40CA FAQ
1.How can I place an order for SMC50J40CA through Aetrix?
Please submit a Request for Quotation (RFQ) for SMC50J40CA 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 SMC50J40CA reliable?
The price and inventory of SMC50J40CA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMC50J40CA is usually 5 days.
3.What payment methods are accepted for SMC50J40CA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMC50J40CA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMC50J40CA?
SMC50J40CA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMC50J40CA 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 SMC50J40CA?
For technical support, including SMC50J40CA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMC50J40CA requirements.
6.How does Aetrix verify that SMC50J40CA is sourced from the original manufacturer or authorized distributors?
All SMC50J40CA 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 SMC50J40CA meets industry standards.
7.What is the process for return or replacement of SMC50J40CA?
All SMC50J40CA units undergo pre-shipment inspection (PSI). If there is an issue with SMC50J40CA, 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 SMC50J40CA part is unused and in its original packaging.
Return procedure for SMC50J40CA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMC50J40CA Tags
-
ESD9B5.0ST5G
onsemi
-
DESD3V3E1BL-7B
Diodes Incorporated
-
ESD5Z3.3T1G
onsemi
-
D5V0H1B2LP-7B
Diodes Incorporated
-
D5V0P1B2LP-7B
Diodes Incorporated
-
DESD5V0U1BA-7
Diodes Incorporated
-
ESD5Z5.0T1G
onsemi
-
DESD5V0U1BB-7
Diodes Incorporated
-
D12V0L1B2LP-7B
Diodes Incorporated
-
PESD2V0Y1BSFYL
Nexperia USA Inc.
-
DF2S5M4CT,L3F
Toshiba Semiconductor and Storage
-
D5V0L1B2WS-7
Diodes Incorporated
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
