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Microchip Technology SMAJ4731E3/TR13
- Part No.:
- SMAJ4731E3/TR13
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ4731E3/TR13.pdf
- Description:
- DIODE ZENER 4.3V 2W DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:2,272
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Product details
Overview
SMAJ4731E3/TR13 from SM Semiconductor is a 4.3 V, 5% tolerance silicon Zener diode in SMA (DO-214AC) package, rated for 2.0 W steady-state power dissipation, 434 mA maximum regulator current at 100°C, and 1070 mA peak surge current; used for transient voltage suppression and precision DC voltage regulation in low-profile power rails.
For engineers reviewing the SMAJ4731E3/TR13 datasheet, SMAJ4731E3/TR13 pinout, SMAJ4731E3/TR13 application, or SMAJ4731E3/TR13 equivalent, key selection criteria include zener voltage tolerance (±5%), thermal resistance (25°C/W), reverse leakage (10 µA @ 1.0 V), knee impedance (400 Ω), and surge current capability under 1/2-sine waveform conditions.
Technical Context
This device operates as a two-terminal voltage reference and transient suppressor, leveraging silicon PN-junction Zener breakdown at 4.3 V nominal with sharp knee characteristics confirmed by dual-point dynamic impedance measurement per MIL-STD-750 Method 2026. It maintains regulation across 1.0–434 mA operating current and -65°C to +150°C ambient range.
Designed for axial-lead mounting in space-constrained PCBs, SMAJ4731E3/TR13 uses void-free UL94V-0 epoxy encapsulation with cathode band polarity marking and matte-tin ROHS-compliant terminations. Its thermal resistance of 25°C/W enables stable operation when lead-mounted without additional heatsinking.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage VZ | 4.3 V ±5% at 58 mA test current - defines precise DC regulation point for low-voltage logic supply clamping |
| Power Dissipation | 2.0 W steady-state - supports continuous regulation in compact 2.5 mm × 4.3 mm SMA footprint |
| Dynamic Impedance | 9.0 Ω max at 58 mA - ensures minimal voltage deviation under load transients |
| Knee Impedance | 400 Ω max at 1.0 mA - guarantees stable turn-on behavior near regulation threshold |
| Reverse Leakage | 10 µA max at 1.0 V - prevents excessive standby current in always-on protection circuits |
| Surge Current | 1070 mA peak (1/2-sine, 1/120 s) - withstands inductive switching spikes in automotive and industrial I/O lines |
| Thermal Resistance | 25°C/W junction-to-lead - enables direct PCB trace heat conduction without thermal vias |
Pinout & Package
Package: SMA (DO-214AC), surface-mount, cathode indicated by band, 0.3 g weight, UL94V-0 epoxy body, ROHS-compliant matte-tin terminations.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / low-side reference node | Connected to ground or lower-potential rail during reverse-biased regulation mode |
| Cathode | Zener breakdown terminal / high-side clamp node | Connected to protected line; conducts when voltage exceeds 4.3 V, shunting surge energy to ground |
Key Features
| Feature | Design Value |
|---|---|
| 5% Zener voltage tolerance | Enables tighter DC rail margining than 10% variants, reducing design guardbanding in 3.3 V–5 V systems |
| 2.0 W power rating in SMA package | Delivers higher sustained clamping energy than SOD-123 or DO-35 Zeners without increasing board area |
| 400 Ω knee impedance | Ensures predictable turn-on below 1 mA, critical for low-power sensor interface protection |
| ROHS-compliant matte-tin plating | Guarantees solderability per MIL-STD-750 Method 2026 and eliminates lead-based assembly concerns |
| UL94V-0 epoxy encapsulation | Meets flammability safety requirements for industrial control and telecom power modules |
Applications
| Industrial Sensor Interface Protection | Automotive Body Control Module (BCM) I/O Clamping |
|---|---|
Use Scenario: Protecting analog input pins of 12-bit ADCs in factory-floor temperature/humidity sensors exposed to relay-coil flyback transients. IC Role / Device Role / Timing Role: Two-terminal shunt regulator that clamps input voltage to ≤4.3 V during >100 ns overvoltage events. Use Value: Prevents ADC saturation and latch-up while maintaining <10 µA leakage at 3.3 V nominal rail, preserving signal integrity. | Use Scenario: Safeguarding LIN bus transceiver inputs against load-dump spikes up to 40 V in door module ECUs. IC Role / Device Role / Timing Role: Fast-response transient voltage suppressor placed directly at connector entry point before ESD diode array. Use Value: Absorbs 1070 mA surge pulses without degradation, enabling compliance with ISO 7637-2 Pulse 1/2a/5a test profiles. |
| Consumer USB-C Power Delivery Monitoring | Telecom DSL Line Card Surge Suppression |
Use Scenario: Regulating reference voltage for VBUS detection circuitry in portable chargers with variable-input buck converters. IC Role / Device Role / Timing Role: Precision 4.3 V Zener reference providing stable threshold for OVP comparator with ±5% accuracy. Use Value: Eliminates need for external voltage divider, reducing BOM count and improving long-term drift stability over -40°C to +85°C. | Use Scenario: Front-end protection of ADSL line drivers against lightning-induced surges on twisted-pair copper loops. IC Role / Device Role / Timing Role: Primary clamping element in series with gas discharge tube (GDT), handling fast-rising transients before GDT fires. Use Value: Withstands repeated 1070 mA surges while maintaining <9.0 Ω dynamic impedance, ensuring consistent clamping voltage across service life. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4731A | Same 4.3 V ±5% rating but in DO-41 package; higher thermal resistance (50°C/W) and lower surge rating (700 mA) | Requires larger PCB footprint and external heatsinking for equivalent 2.0 W operation | Select when through-hole assembly or legacy DO-41 compatibility is required |
| BZX84-C4V3 | 4.3 V ±5% in SOT-23; lower power (300 mW), higher dynamic impedance (90 Ω), and no specified surge rating | Limited to low-energy signal-line protection; unsuitable for power rail clamping | Select only for space-constrained signal-level regulation where surge immunity is not required |
Compared with 1N4731A and BZX84-C4V3, SMAJ4731E3/TR13 uniquely delivers 2.0 W regulation in a surface-mount SMA package with validated 1070 mA surge capability-making it the only option among the three suitable for industrial-grade power rail clamping without layout redesign.
Availability
SMAJ4731E3/TR13 is available at Aetrix Electronics and suitable for industrial sensor interfaces, automotive BCM I/O clamping, and telecom DSL line card surge suppression requiring stable component supply and long-lifecycle availability.
Supply support for SMAJ4731E3/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 Semiconductor is a Taiwan-based manufacturer specializing in discrete semiconductors including Zener diodes, TVS devices, rectifiers, and bridge rectifiers for industrial and automotive markets.
SMAJ47xxA series was designed specifically for high-reliability transient suppression and precision DC voltage regulation in compact surface-mount applications where thermal performance and surge robustness are critical.
FAQ
What is the Zener voltage tolerance of SMAJ4731E3/TR13?
The SMAJ4731E3/TR13 has a Zener voltage tolerance of ±5%, meaning its breakdown voltage is guaranteed between 4.085 V and 4.515 V at 58 mA test current. This tighter tolerance compared to standard 10% Zeners allows more accurate voltage regulation in sensitive analog and power monitoring circuits. The 'A' suffix in the part number explicitly denotes this 5% tolerance per the manufacturer's datasheet revision dated Feb. 29, 2012.
Does SMAJ4731E3/TR13 meet ROHS requirements?
Yes, SMAJ4731E3/TR13 meets ROHS requirements with annealed matte-tin plating on its terminals, fully compliant with EU Directive 2011/65/EU. The device uses lead-free solderable terminations verified per MIL-STD-750 Method 2026 and is encapsulated in UL94V-0 void-free thermosetting epoxy. No lead or restricted substances exceed allowable thresholds, and full material declarations are available upon request for SMAJ4731E3/TR13.
What is the maximum surge current rating for SMAJ4731E3/TR13?
The maximum peak surge current for SMAJ4731E3/TR13 is 1070 mA, measured using a 1/2 sine wave pulse of 1/120 second duration at 25°C ambient. This rating reflects its capability to absorb transient energy from inductive load switching or electrostatic discharge events without parametric shift or failure. The value is confirmed in Table 1 of the official SMAJ4728A–SMAJ4751A datasheet and applies specifically to SMAJ4731E3/TR13.
Can SMAJ4731E3/TR13 be used as a replacement for SMAJ4731A?
Yes, SMAJ4731E3/TR13 is functionally identical to SMAJ4731A in electrical specifications, package (SMA/DO-214AC), and marking - the 'E3/TR13' suffix indicates tape-and-reel packaging per EIA-481 standard, while 'A' denotes the same 5% tolerance. No electrical or mechanical differences exist between SMAJ4731E3/TR13 and SMAJ4731A; the suffix change reflects only packaging format and reel quantity, not device performance.
What is the thermal resistance junction-to-lead for SMAJ4731E3/TR13?
The thermal resistance junction-to-lead (RθJL) for SMAJ4731E3/TR13 is 25°C/W, as specified in the Maximum Ratings table of the official datasheet. This value enables direct heat conduction from the silicon die to the PCB copper via the device leads, allowing full 2.0 W power dissipation without additional heatsinking when mounted on ≥10 mm² 1-oz copper pads. It is measured under standardized lead-mount conditions per JEDEC JESD51-14.
SMAJ4731E3/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):
- 4.3 V
- Tolerance:
- ±10%
- Power - Max:
- 2 W
- Impedance (Max) (Zzt):
- 9 Ohms
- Current - Reverse Leakage @ Vr:
- 10 µA @ 1 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
SMAJ4731E3/TR13 FAQ
1.How can I place an order for SMAJ4731E3/TR13 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ4731E3/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 SMAJ4731E3/TR13 reliable?
The price and inventory of SMAJ4731E3/TR13 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ4731E3/TR13 is usually 5 days.
3.What payment methods are accepted for SMAJ4731E3/TR13?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ4731E3/TR13 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ4731E3/TR13?
SMAJ4731E3/TR13 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ4731E3/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 SMAJ4731E3/TR13?
For technical support, including SMAJ4731E3/TR13 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ4731E3/TR13 requirements.
6.How does Aetrix verify that SMAJ4731E3/TR13 is sourced from the original manufacturer or authorized distributors?
All SMAJ4731E3/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 SMAJ4731E3/TR13 meets industry standards.
7.What is the process for return or replacement of SMAJ4731E3/TR13?
All SMAJ4731E3/TR13 units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ4731E3/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 SMAJ4731E3/TR13 part is unused and in its original packaging.
Return procedure for SMAJ4731E3/TR13:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ4731E3/TR13 Tags
-
MMBZ5240B-7-F
Diodes Incorporated
-
BZT52C5V6T-7
Diodes Incorporated
-
MMSZ5231B-7-F
Diodes Incorporated
-
BZT52C15-7-F
Diodes Incorporated
-
BZX84C3V3LT1G
onsemi
-
MMSZ5245BS-7-F
Diodes Incorporated
-
MMSZ4682T1G
onsemi
-
BZT52C15S-7-F
Diodes Incorporated
-
MM5Z5V1ST1G
onsemi
-
SMAJ4744A-TP
Micro Commercial Co
-
BZT52C3V6LP-7
Diodes Incorporated
-
SMAZ12-13-F
Diodes Incorporated
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