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Diodes Incorporated SMAJ33CA-13
- Part No.:
- SMAJ33CA-13
- Manufacturer:
- Diodes Incorporated
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ33CA-13.pdf
- Description:
- TVS DIODE 33VWM 53.3VC SMA
- Quantity:
- Payment:
- Shipping:
Inventory:8,108
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Product details
Overview
SMAJ33CA-13 from Diodes Incorporated is a 400W bi-directional transient voltage suppressor (TVS) diode in SMA package, designed for clamping ESD and surge transients on data lines and power rails. It features a 33V reverse standoff voltage (VRWM), 53.3V max clamping voltage at 7.5A peak pulse current, and operates from –55°C to +150°C - used in industrial Ethernet port protection and automotive body control module I/O interfaces.
For engineers reviewing the SMAJ33CA-13 datasheet, SMAJ33CA-13 pinout, SMAJ33CA-13 application, or SMAJ33CA-13 equivalent, key selection criteria include clamping voltage margin vs. system rail, bidirectional capability for AC-coupled lines, JEDEC-compliant 8.3ms surge rating, and RoHS-compliant matte tin plating compatibility with lead-free reflow.
Technical Context
This bi-directional TVS diode uses glass-passivated junction construction for stable breakdown behavior and fast response (<1 ns). Its symmetrical I–V characteristic enables protection of AC signals or floating buses without polarity concerns, unlike unidirectional variants requiring cathode orientation.
Clamping performance is validated under standardized 8.3ms half-sine waveform per JEDEC, with derating above 25°C ambient per Fig. 1. The device sustains 40A non-repetitive forward surge (IFSM) and exhibits <5 µA reverse leakage at VRWM - critical for low-power sensor interface integrity.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power | 400 W - sustains single transient events up to 400W without failure, per 8.3ms waveform |
| Reverse Standoff Voltage | 33 V - maximum continuous DC or RMS voltage before significant leakage begins |
| Breakdown Voltage | 36.7–40.6 V @ 1 mA - ensures reliable triggering above system operating voltage |
| Max Clamping Voltage | 53.3 V @ 7.5 A - limits downstream voltage to safe level during surge |
| Peak Pulse Current | 7.5 A - peak current handled at rated clamping voltage |
| Operating Temperature | –55°C to +150°C - supports under-hood automotive and industrial ambient conditions |
| Package | SMA - surface-mount, UL 94V-0 molded plastic case with 0.064 g mass |
Pinout & Package
SMA package: 2-terminal surface-mount device with cathode band omitted (bi-directional); terminals are anode and cathode, electrically symmetric. Case material is flame-retardant molded plastic (UL 94V-0), lead finish is matte tin (RoHS compliant).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Transient current entry (either polarity) | Accepts surge current during positive or negative overvoltage event |
| Cathode | Transient current exit (either polarity) | Completes low-impedance path to ground or return rail during clamping |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated die | Ensures stable, repeatable breakdown voltage and long-term reliability under thermal cycling |
| Bi-directional configuration | Protects AC-coupled or floating signal lines (e.g., RS-485, CAN, USB D+/D−) without polarity constraints |
| Fast response time | <1 ns turn-on - intercepts ESD events before sensitive ICs experience overstress |
| RoHS-compliant matte tin plating | Compatible with Pb-free reflow profiles (J-STD-020C Level 1 moisture sensitivity) |
| 400W peak pulse rating | Meets IEC 61000-4-5 Level 4 (4 kV line-to-line, 2 kV line-to-ground) surge immunity requirements |
Applications
| Industrial Ethernet Port Protection | Automotive Body Control Module I/O |
|---|---|
Use Scenario: Protecting RJ45 PHY interface against ESD (IEC 61000-4-2) and lightning-induced surges on twisted-pair lines. IC Role / Device Role / Timing Role: Bi-directional clamping element placed between differential pair and PHY transceiver input pins. Use Value: Limits voltage to ≤53.3 V during 7.5 A transient, preserving PHY's 60 V absolute maximum rating and maintaining signal integrity. | Use Scenario: Safeguarding LIN bus or switch inputs in door modules exposed to load dump and jump-start transients. IC Role / Device Role / Timing Role: Primary surge shunt on 12 V supply rail and digital input lines connected to microcontroller GPIO. Use Value: Withstands 40 A surge (IFSM) and clamps to 53.3 V, preventing latch-up or permanent damage to 5 V tolerant MCU inputs. |
| USB 2.0 Data Line Protection | DC Power Input Surge Suppression |
Use Scenario: ESD protection on USB D+ and D− lines in portable medical devices requiring Class 4 IEC 61000-4-2 compliance. IC Role / Device Role / Timing Role: Low-capacitance (≈20 pF at 0 V) bi-directional TVS placed directly at USB connector. Use Value: Adds <1 pF parasitic capacitance per line, avoiding signal rise-time degradation while suppressing ±15 kV contact discharge. | Use Scenario: Secondary-level surge suppression on 24 V DC input of programmable logic controller (PLC) I/O card. IC Role / Device Role / Timing Role: Parallel-connected clamping device across input filter capacitor, downstream of primary MOV. Use Value: Provides precise 53.3 V clamping threshold to protect 36 V-rated DC/DC converter input stage during 1 kV/500 A surge events. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ33CA-13 | 600W peak power, larger SMB package (5.3 mm × 4.6 mm vs. SMA 4.6 mm × 2.9 mm) | Better thermal dissipation for higher-duty-cycle surges; requires more PCB area | Select when surge repetition rate exceeds 4 pulses/minute or board layout allows larger footprint |
| P6SMB33CA | 600W rating, same SMB package, but higher clamping voltage (53.3 V → 56.3 V at 7.5 A) | Marginally reduced protection level; not suitable where 53.3 V clamping is design-critical | Choose only if cost or inventory consolidation outweighs 3 V clamping penalty |
Compared with SMBJ33CA-13 and P6SMB33CA, SMAJ33CA-13 offers optimal balance of compact size, precise 53.3 V clamping, and 400W capability - ideal for space-constrained, high-density layouts where exact voltage margin matters.
Availability
SMAJ33CA-13 is available at Aetrix Electronics and suitable for industrial Ethernet port protection, automotive body control module I/O, and USB 2.0 data line protection requiring stable component supply and consistent RoHS-compliant delivery.
Supply support for SMAJ33CA-13 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
Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design and manufacturing operations across Asia and the US.
The SMAJ series belongs to Diodes' transient voltage suppressor product line, engineered specifically for robust, low-cost, surface-mount surge protection in automotive, industrial, and communications infrastructure applications.
FAQ
What is the difference between SMAJ33CA-13 and SMAJ33A-13?
SMAJ33CA-13 is bi-directional (denoted by "C"), providing symmetrical clamping for both polarities - essential for AC or floating lines. SMAJ33A-13 is unidirectional, with a defined cathode band and only clamps negative transients relative to its cathode. They share identical VRWM (33 V) and clamping voltage (53.3 V), but differ in polarity handling and marking.
Does SMAJ33CA-13 require a heatsink for 400W operation?
No - the 400W rating applies to a single, non-repetitive 8.3ms surge under specified test conditions (TA = 25°C, terminals at ambient). Continuous power dissipation is limited to 1.0 W at TL = 75°C. For repetitive surges, derating per Fig. 1 is mandatory; no heatsink is needed for typical transient duty cycles.
Can SMAJ33CA-13 be used on a 24 V DC power rail?
Yes - its 33 V VRWM provides 9 V margin above 24 V nominal, ensuring minimal leakage (<5 µA) during normal operation. The 53.3 V clamping voltage protects downstream 36 V-rated components during transients, making it suitable for 24 V industrial power inputs with IEC 61000-4-5 compliance targets.
Is SMAJ33CA-13 compatible with lead-free reflow soldering?
Yes - it features matte tin plating and meets J-STD-020C Level 1 moisture sensitivity. It is qualified for standard Pb-free reflow profiles (peak temperature ≤260°C), with no pre-baking required. The UL 94V-0 mold compound withstands multiple reflow cycles without delamination or cracking.
SMAJ33CA-13 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Package/Case:
- DO-214AC, SMA
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Discontinued at Digi-Key
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 33V
- Voltage - Breakdown (Min):
- 36.7V
- Voltage - Clamping (Max) @ Ipp:
- 53.3V
- Current - Peak Pulse (10/1000µs):
- 7.5A
- Power - Peak Pulse:
- 400W
- 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:
- SMA
SMAJ33CA-13 FAQ
1.How can I place an order for SMAJ33CA-13 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ33CA-13 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 SMAJ33CA-13 reliable?
The price and inventory of SMAJ33CA-13 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ33CA-13 is usually 5 days.
3.What payment methods are accepted for SMAJ33CA-13?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ33CA-13 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ33CA-13?
SMAJ33CA-13 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ33CA-13 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 SMAJ33CA-13?
For technical support, including SMAJ33CA-13 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ33CA-13 requirements.
6.How does Aetrix verify that SMAJ33CA-13 is sourced from the original manufacturer or authorized distributors?
All SMAJ33CA-13 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 SMAJ33CA-13 meets industry standards.
7.What is the process for return or replacement of SMAJ33CA-13?
All SMAJ33CA-13 units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ33CA-13, 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 SMAJ33CA-13 part is unused and in its original packaging.
Return procedure for SMAJ33CA-13:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ33CA-13 Tags
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ESD9B5.0ST5G
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