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Microchip Technology SMAJ4746AE3/TR13
- Part No.:
- SMAJ4746AE3/TR13
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ4746AE3/TR13.pdf
- Description:
- DIODE ZENER 18V 2W DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:7,447
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Product details
Overview
SMAJ4746AE3/TR13 from SM Semiconductors is a 18.0 V, 5% tolerance Zener diode in SMA (DO-214AC) package, rated for 2.0 W steady-state power dissipation, 14.0 Ω maximum dynamic impedance at 14.0 mA test current, and 100 mA maximum reverse current at 13.7 V, used for overvoltage protection of I/O lines and sensor interfaces in industrial control systems.
For engineers reviewing the SMAJ4746AE3/TR13 datasheet, SMAJ4746AE3/TR13 pinout, SMAJ4746AE3/TR13 application, or SMAJ4746AE3/TR13 equivalent, key selection criteria include zener voltage tolerance, surge current rating (250 A), thermal resistance (25 °C/W), and ROHS-compliant matte-tin plating for reliable solderability.
Technical Context
This device operates as a silicon planar Zener diode optimized for transient voltage suppression in low-energy circuits. It maintains regulation across 14.0 mA to 100 mA operating current range with sharp knee characteristics verified by dual-point Zener impedance measurement per MIL-STD-750 Method 2026.
Designed for axial-lead mounting with cathode band polarity marking, it delivers stable clamping during 1/2-sine 120 Hz surge events up to 250 A while sustaining junction temperatures from –65 °C to +150 °C without derating below 100 °C ambient.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage VZ | 18.0 V ±5% at 14.0 mA - defines precise clamping threshold for 13.7 V minimum and 14.3 V maximum working voltage compliance |
| Power Dissipation PM(AV) | 2.0 W - supports continuous DC regulation without heatsink in PCB-constrained space-limited designs |
| Dynamic Impedance ZZT | 20.0 Ω max at 14.0 mA - ensures minimal voltage deviation under load transients in precision reference applications |
| Surge Current IZSM | 250 A - withstands single-event lightning-induced surges per 1/2-sine waveform (120 Hz, 1/120 s duration) |
| Reverse Leakage IR | 5 µA max at 13.7 V - guarantees low standby power loss in battery-backed sensor nodes and always-on interfaces |
| Thermal Resistance RθJL | 25 °C/W - enables direct lead-to-PCB heat transfer without thermal vias for cost-sensitive consumer electronics |
| Operating Temperature | –65 °C to +150 °C - qualified for under-hood automotive and industrial motor drive environments |
Pinout & Package
Package: SMA (DO-214AC), void-free thermosetting epoxy case with cathode band marking; weight ≈ 0.3 g; ROHS-compliant matte-tin plating on annealed copper leads.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current sink during forward bias | Connected to ground or lower-potential node; enables standard cathode-up PCB layout orientation |
| Cathode | Clamping node during reverse breakdown | Connected to protected line; band-marked terminal must be routed to signal path requiring overvoltage limiting |
Key Features
| Feature | Design Value |
|---|---|
| 5% Zener voltage tolerance | Enables tighter system-level voltage margin control vs. 10% variants, reducing need for post-regulation filtering |
| 250 A peak surge rating | Meets IEC 61000-4-5 Level 3 surge immunity requirements for industrial Ethernet and CAN bus interfaces |
| 25 °C/W junction-to-lead thermal resistance | Permits full 2.0 W power handling with only lead-frame conduction-no thermal pads or vias required |
| ROHS-compliant matte-tin plating | Ensures consistent wetting and intermetallic formation during reflow, eliminating solder joint voiding in high-volume SMT assembly |
| Sharp knee impedance profile | Validated by dual-point ZZK/ZZT measurement-rejects unstable units with soft breakdown onset |
Applications
| Industrial Sensor Protection | Automotive Body Control Module |
|---|---|
Use Scenario: Protecting analog output lines of pressure and temperature sensors exposed to relay coil flyback in PLC cabinets. IC Role / Device Role / Timing Role: Zener clamping diode placed between sensor output and microcontroller ADC input. Use Value: Limits transient spikes to ≤13.7 V, preserving 12-bit ADC accuracy and preventing ESD latch-up in downstream MCU. | Use Scenario: Safeguarding LIN bus transceiver inputs against load dump and alternator ripple in door module ECUs. IC Role / Device Role / Timing Role: Standoff protection device connected between LIN data line and chassis ground. Use Value: Clamps 100 V/10 ms load dump events to <18 V, maintaining transceiver functional integrity per ISO 7637-2 Pulse 5a. |
| Consumer Appliance Power Monitoring | Telecom Line Interface Card |
Use Scenario: Overvoltage guard for AC zero-cross detection circuitry in smart washing machine motor controllers. IC Role / Device Role / Timing Role: Shunt regulator on optocoupler input side, referenced to neutral line. Use Value: Maintains stable 18 V clamp during 264 VAC surges, ensuring accurate zero-cross timing within ±100 µs window. | Use Scenario: Secondary-side transient suppression on RS-485 receiver inputs in base station backhaul cards. IC Role / Device Role / Timing Role: Low-capacitance shunt limiter on differential pair before receiver IC. Use Value: Adds <0.5 pF parasitic capacitance while delivering 250 A surge capability-preserves signal integrity up to 10 Mbps. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode protection applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4746A | Same 18 V nominal voltage but 10% tolerance; DO-41 package with higher RθJA (65 °C/W) | Larger footprint and lower surge rating (150 A); unsuitable for space-constrained PCBs | Select when legacy DO-41 socket compatibility is required and thermal budget allows larger heatsinking |
| BZX84-C18 | 18 V, 5% tolerance but SOT-23 package; 350 mW power rating and 200 mA max IZM | Lower power handling limits use to signal-level protection only-not for power rail clamping | Choose for ultra-compact board area where surge energy is limited to <0.1 J |
Compared with 1N4746A and BZX84-C18, SMAJ4746AE3/TR13 uniquely combines 5% tolerance, 2.0 W power, 250 A surge, and SMA package-making it optimal for industrial-grade I/O protection where precision, robustness, and density are jointly critical.
Availability
SMAJ4746AE3/TR13 is available at Aetrix Electronics and suitable for industrial sensor interfaces, automotive body control modules, consumer appliance power monitoring, and telecom line interface cards requiring stable component supply with traceable lot history and full RoHS compliance.
Supply support for SMAJ4746AE3/TR13 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
SM Semiconductors is a Taiwan-based manufacturer specializing in discrete semiconductor devices including Zener diodes, TVS diodes, rectifiers, and bridge rectifiers for industrial and automotive markets.
The SMAJ47xxA series was developed specifically for high-reliability transient voltage suppression in space-constrained, high-surge environments-emphasizing tight voltage tolerance, repeatable surge performance, and lead-free manufacturability.
FAQ
What is the exact Zener voltage tolerance for SMAJ4746AE3/TR13?
The SMAJ4746AE3/TR13 has a ±5% Zener voltage tolerance at 14.0 mA test current, resulting in a guaranteed breakdown range of 17.1 V to 18.9 V. This tighter tolerance than standard 10% Zeners enables more predictable clamping behavior in precision analog circuits and reduces design margin uncertainty compared to wider-tolerance alternatives like SMAJ4746A (no suffix).
Does SMAJ4746AE3/TR13 meet RoHS requirements?
Yes, SMAJ4746AE3/TR13 uses ROHS-compliant annealed matte-tin plating on its copper leads, fully compliant with Directive 2011/65/EU and IPC-J-STD-609A Class 1. The device carries no lead, mercury, cadmium, hexavalent chromium, PBB, or PBDE substances above threshold limits, and is suitable for lead-free reflow assembly per JEDEC J-STD-020D.3.
What is the maximum surge current rating for SMAJ4746AE3/TR13?
The SMAJ4746AE3/TR13 is rated for 250 A peak surge current under standardized 1/2-sine wave conditions (120 Hz, 1/120 second duration) at 25 °C ambient. This rating is validated per the manufacturer's test method in Table 1 and supports compliance with IEC 61000-4-5 Level 3 surge immunity testing for industrial equipment.
Can SMAJ4746AE3/TR13 be used in place of SMAJ4746A?
Yes, SMAJ4746AE3/TR13 is a direct replacement for SMAJ4746A with identical electrical specifications except for the tighter ±5% voltage tolerance and RoHS-compliant plating. Both share the same SMA (DO-214AC) package, pinout, thermal resistance, and surge rating-no PCB or schematic changes are needed when upgrading from SMAJ4746A to SMAJ4746AE3/TR13.
What is the thermal resistance junction-to-lead for SMAJ4746AE3/TR13?
The thermal resistance junction-to-lead (RθJL) for SMAJ4746AE3/TR13 is 25 °C/W, measured under specified test conditions. This value reflects efficient heat conduction through the copper leads to the PCB, enabling full 2.0 W power dissipation without additional thermal vias or heatsinks-critical for compact, high-density layouts in industrial and automotive modules.
SMAJ4746AE3/TR13 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- DO-214AC, SMA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 18 V
- Tolerance:
- ±5%
- Power - Max:
- 2 W
- Impedance (Max) (Zzt):
- 20 Ohms
- Current - Reverse Leakage @ Vr:
- 5 µA @ 13.7 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.2 V @ 200 mA
- Operating Temperature:
- -55°C ~ 150°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC
SMAJ4746AE3/TR13 FAQ
1.How can I place an order for SMAJ4746AE3/TR13 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ4746AE3/TR13 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 SMAJ4746AE3/TR13 reliable?
The price and inventory of SMAJ4746AE3/TR13 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ4746AE3/TR13 is usually 5 days.
3.What payment methods are accepted for SMAJ4746AE3/TR13?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ4746AE3/TR13 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ4746AE3/TR13?
SMAJ4746AE3/TR13 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ4746AE3/TR13 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 SMAJ4746AE3/TR13?
For technical support, including SMAJ4746AE3/TR13 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ4746AE3/TR13 requirements.
6.How does Aetrix verify that SMAJ4746AE3/TR13 is sourced from the original manufacturer or authorized distributors?
All SMAJ4746AE3/TR13 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 SMAJ4746AE3/TR13 meets industry standards.
7.What is the process for return or replacement of SMAJ4746AE3/TR13?
All SMAJ4746AE3/TR13 units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ4746AE3/TR13, 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 SMAJ4746AE3/TR13 part is unused and in its original packaging.
Return procedure for SMAJ4746AE3/TR13:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ4746AE3/TR13 Tags
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MMBZ5240B-7-F
Diodes Incorporated
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BZT52C5V6T-7
Diodes Incorporated
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MMSZ5231B-7-F
Diodes Incorporated
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BZT52C15-7-F
Diodes Incorporated
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BZX84C3V3LT1G
onsemi
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MMSZ5245BS-7-F
Diodes Incorporated
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MMSZ4682T1G
onsemi
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BZT52C15S-7-F
Diodes Incorporated
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MM5Z5V1ST1G
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SMAJ4744A-TP
Micro Commercial Co
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BZT52C3V6LP-7
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SMAZ12-13-F
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