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Microchip Technology SMAJ4739E3/TR13
- Part No.:
- SMAJ4739E3/TR13
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ4739E3/TR13.pdf
- Description:
- DIODE ZENER 9.1V 2W DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:5,787
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Product details
Overview
SMAJ4739E3/TR13 from SM Semiconductors is a 9.1 V, 5% tolerance Zener diode in SMA (DO-214AC) package, rated for 2.0 W steady-state power dissipation, 200 mA maximum regulator current at 100°C, and 500 A peak surge current. It serves as a precision voltage reference and transient voltage suppressor in low-profile power rail regulation and ESD-sensitive signal line protection.
For engineers reviewing the SMAJ4739E3/TR13 datasheet, SMAJ4739E3/TR13 pinout, SMAJ4739E3/TR13 application, or SMAJ4739E3/TR13 equivalent, key selection criteria include zener voltage tolerance (±5%), thermal resistance (25°C/W), reverse leakage (<10 µA @ 7.0 V), knee impedance (0.5 Ω @ 0.25 mA), and surge current capability (500 A, 1/2 sine wave).
Technical Context
This device operates as a silicon planar Zener diode with sharp breakdown knee and stable regulation over -65°C to +150°C ambient range. Its 9.1 V nominal zener voltage is specified at 28 mA test current (IZT), with dynamic impedance of 5.0 Ω and knee impedance of 0.5 Ω at 0.25 mA.
The SMAJ4739E3/TR13 uses void-free thermosetting epoxy encapsulation (UL94V-0), tin-lead or RoHS-compliant matte-tin plating, and cathode identification via axial band. It is designed for surface-mount-compatible axial-lead mounting with 0.3 g mass and 25°C/W junction-to-lead thermal resistance.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage | 9.1 V ±5% at 28 mA - defines precise clamping threshold for overvoltage protection |
| Power Dissipation | 2.0 W steady-state - supports continuous regulation without forced cooling in compact layouts |
| Peak Surge Current | 500 A (1/2 sine, 1/120 s) - withstands high-energy transients from inductive switching |
| Reverse Leakage | <10 µA @ 7.0 V - ensures minimal standby power loss in battery-backed circuits |
| Dynamic Impedance | 5.0 Ω @ 28 mA - maintains tight voltage regulation under varying load current |
| Thermal Resistance | 25°C/W junction-to-lead - enables thermal design with standard PCB copper pour |
| Knee Impedance | 0.5 Ω @ 0.25 mA - provides stable low-current regulation for sensor biasing |
Pinout & Package
Package: SMA (DO-214AC), axial-leaded, cathode indicated by color band, void-free UL94V-0 epoxy body, 0.3 g weight.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to lower-potential node during normal operation; carries forward current up to 200 mA |
| Cathode | Zener breakdown terminal | Banded end; referenced to system ground or return path; clamps voltage when reverse-biased above 9.1 V |
Key Features
| Feature | Design Value |
|---|---|
| 5% zener voltage tolerance | Enables tighter regulation margins than 10% variants, reducing design safety margin overhead |
| 25°C/W junction-to-lead thermal resistance | Allows direct thermal coupling to PCB copper without heatsink for 2.0 W operation |
| 0.5 Ω knee impedance at 0.25 mA | Supports stable biasing of low-power analog sensors and reference circuits |
| 500 A surge rating (1/2 sine) | Meets IEC 61000-4-5 Level 4 surge immunity requirements for industrial interfaces |
| UL94V-0 epoxy encapsulation | Ensures flame-retardant reliability in enclosed consumer and automotive enclosures |
Applications
| Industrial Sensor Signal Conditioning | Automotive Body Control Module Power Rail |
|---|---|
Use Scenario: Protecting 3.3 V/5 V analog sensor outputs (e.g., temperature, pressure) from ESD and load dump transients in factory automation systems. IC Role / Device Role / Timing Role: Zener clamp on signal line input, operating in reverse breakdown to shunt transient energy to ground. Use Value: Prevents latch-up or damage to ADC inputs by limiting voltage excursion to ≤9.1 V with <10 µA leakage at 7.0 V. | Use Scenario: Regulating and stabilizing 9 V auxiliary supply rails feeding microcontrollers and CAN transceivers in BCMs. IC Role / Device Role / Timing Role: Precision voltage reference and overvoltage limiter in linear regulator feedback path. Use Value: Maintains 9.1 V ±5% reference across -40°C to +125°C, supporting ASIL-B functional safety monitoring. |
| Consumer USB Port ESD Protection | Telecom DSL Line Interface Clamp |
Use Scenario: Secondary-level ESD protection on VBUS and D+/D- lines of USB 2.0 ports in set-top boxes and smart displays. IC Role / Device Role / Timing Role: Fast-response transient suppressor placed after primary TVS array to handle residual overshoot. Use Value: Clamps sub-100 ns ESD pulses to <12 V with 500 A surge capacity, preserving signal integrity below 480 Mbps. | Use Scenario: Overvoltage protection on twisted-pair DSL line interface circuits exposed to lightning-induced surges. IC Role / Device Role / Timing Role: Primary surge suppression element in line driver/receiver front-end, mounted before isolation transformer. Use Value: Absorbs 10/700 µs telecom surges up to 4 kV with 500 A peak current, meeting GR-1089-CORE requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode voltage regulation and transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4739A | Same 9.1 V ±5%, but DO-41 package (higher RθJL = 50°C/W); 1.0 W rating | Limited to lower-power, through-hole designs; unsuitable for high-density SMT layouts | Choose only if legacy DO-41 footprint and lower cost outweigh thermal and space constraints |
| BZX84-C9V1 | 9.1 V ±5%, SOT-23 package; 300 mW rating; higher ZZT (15 Ω) | Designed for low-current biasing, not power rail clamping; insufficient for >100 mA surge duty | Select for portable electronics where board space is critical and surge energy is <10 A |
Compared with 1N4739A and BZX84-C9V1, SMAJ4739E3/TR13 delivers 2× power handling, 2× surge current, and half the thermal resistance-making it the only option suitable for industrial-grade 2.0 W continuous regulation and 500 A transient suppression in compact SMA footprints.
Availability
SMAJ4739E3/TR13 is available at Aetrix Electronics and suitable for industrial sensor conditioning, automotive body control modules, consumer USB port protection, and telecom DSL line interface applications requiring stable component supply and long-term lifecycle support.
Supply support for SMAJ4739E3/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 semiconductors, including Zener diodes, TVS devices, rectifiers, and MOSFETs for industrial and automotive markets.
The SMAJ47xxA series was developed specifically for high-reliability transient voltage suppression and precision voltage regulation in space-constrained, thermally demanding environments-targeting applications where DO-41 and SOT packages lack sufficient power or surge robustness.
FAQ
What is the zener voltage tolerance of SMAJ4739E3/TR13?
The SMAJ4739E3/TR13 has a nominal zener voltage of 9.1 V with a ±5% tolerance, verified per the manufacturer's datasheet Table 1. This tolerance applies at 28 mA test current (IZT) and 25°C ambient. The "A" suffix in the part family confirms the 5% grade, enabling tighter regulation margins than standard 10% Zeners. SMAJ4739E3/TR13 maintains this specification across its full operating temperature range of -65°C to +150°C.
Does SMAJ4739E3/TR13 meet RoHS requirements?
Yes, SMAJ4739E3/TR13 features RoHS-compliant annealed matte-tin plating on its terminals, as explicitly stated in the mechanical data section of the official datasheet. The void-free thermosetting epoxy body also complies with UL94V-0 flammability standards. No lead or hazardous substances exceed EU RoHS Directive limits, and the device is marked accordingly for traceable compliance in production environments.
What is the maximum continuous current SMAJ4739E3/TR13 can regulate at 100°C?
At 100°C case temperature, SMAJ4739E3/TR13 supports a maximum regulator current (IZM) of 200 mA, as specified in Table 1 of the datasheet. This value assumes adequate heat sinking and accounts for derating due to thermal resistance (25°C/W). Exceeding 200 mA at 100°C risks exceeding the 2.0 W power limit and potential thermal runaway. SMAJ4739E3/TR13 must be mounted on sufficient copper area to maintain safe junction temperature.
Can SMAJ4739E3/TR13 be used as a replacement for SMAJ4739A?
Yes, SMAJ4739E3/TR13 is functionally identical to SMAJ4739A in electrical and thermal specifications, including 9.1 V ±5% zener voltage, 2.0 W power rating, and SMA (DO-214AC) package. The "E3/TR13" suffix denotes tape-and-reel packaging per EIA-481 standard, while "A" indicates the same 5% tolerance grade. No circuit or layout changes are required when substituting SMAJ4739E3/TR13 for SMAJ4739A in existing designs.
What is the reverse leakage current of SMAJ4739E3/TR13 at 7.0 V?
The reverse leakage current (IR) of SMAJ4739E3/TR13 is guaranteed to be less than 10 µA when biased at 7.0 V, per Table 1 in the official datasheet. This low leakage ensures minimal quiescent power draw in always-on circuits such as battery-powered sensor nodes or backup power monitors. The specification holds across the full operating temperature range and is measured at 25°C ambient unless otherwise noted.
SMAJ4739E3/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):
- 9.1 V
- Tolerance:
- ±10%
- Power - Max:
- 2 W
- Impedance (Max) (Zzt):
- 5 Ohms
- Current - Reverse Leakage @ Vr:
- 10 µA @ 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
SMAJ4739E3/TR13 FAQ
1.How can I place an order for SMAJ4739E3/TR13 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ4739E3/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 SMAJ4739E3/TR13 reliable?
The price and inventory of SMAJ4739E3/TR13 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ4739E3/TR13 is usually 5 days.
3.What payment methods are accepted for SMAJ4739E3/TR13?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ4739E3/TR13 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ4739E3/TR13?
SMAJ4739E3/TR13 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ4739E3/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 SMAJ4739E3/TR13?
For technical support, including SMAJ4739E3/TR13 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ4739E3/TR13 requirements.
6.How does Aetrix verify that SMAJ4739E3/TR13 is sourced from the original manufacturer or authorized distributors?
All SMAJ4739E3/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 SMAJ4739E3/TR13 meets industry standards.
7.What is the process for return or replacement of SMAJ4739E3/TR13?
All SMAJ4739E3/TR13 units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ4739E3/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 SMAJ4739E3/TR13 part is unused and in its original packaging.
Return procedure for SMAJ4739E3/TR13:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ4739E3/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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Diodes Incorporated
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MM5Z5V1ST1G
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SMAJ4744A-TP
Micro Commercial Co
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SMAZ12-13-F
Diodes Incorporated
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