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Microchip Technology SMAJ4745AE3/TR13
- Part No.:
- SMAJ4745AE3/TR13
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ4745AE3/TR13.pdf
- Description:
- DIODE ZENER 16V 2W DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:8,260
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Product details
Overview
SMAJ4745AE3/TR13 from SM Semiconductors is a 16 V, ±5% tolerance silicon Zener diode in SMA (DO-214AC) package, rated for 2.0 W steady-state power dissipation, 15.5 mA test current (IZT), and 114 mA maximum regulator current (IZM) at 100°C junction temperature, used for overvoltage clamping in DC power rails and signal line protection.
For engineers reviewing the SMAJ4745AE3/TR13 datasheet, SMAJ4745AE3/TR13 pinout, SMAJ4745AE3/TR13 application, or SMAJ4745AE3/TR13 equivalent, key selection criteria include breakdown voltage tolerance, surge current capability (285 A), thermal resistance (25 °C/W), and ROHS-compliant matte-tin plating for reliable solderability in high-density PCB layouts.
Technical Context
This device operates as a unidirectional transient voltage suppressor (TVS) with sharp Zener breakdown knee, specified at 15.5 mA test current and validated for stable regulation across -65°C to +150°C operating temperature range. Its 16.0 V nominal Zener voltage (VZ) is measured under DC conditions with 10% tolerance band per JEDEC standard.
The SMAJ4745AE3/TR13 exhibits 16.0 Ω dynamic impedance (ZZT) at IZT and ≤0.25 µA reverse leakage (IR) at VR = 12.2 V, enabling precise voltage reference and fast transient response in low-energy surge events such as ESD or inductive switching spikes.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage VZ | 16.0 V ±5% at 15.5 mA - defines clamping threshold for overvoltage protection |
| Power Dissipation PM(AV) | 2.0 W - limits continuous thermal load without heatsink |
| Peak Surge Current Izsm | 285 A - supports single-pulse transient suppression per 1/2-sine wave standard |
| Dynamic Impedance ZZT | 16.0 Ω at IZT - ensures minimal voltage shift during regulation current variation |
| Thermal Resistance RθJL | 25 °C/W - determines junction-to-lead temperature rise under steady-state bias |
| Reverse Leakage IR | ≤0.25 µA at VR = 12.2 V - guarantees low standby power loss in high-impedance circuits |
| Operating Temperature | -65°C to +150°C - enables deployment in automotive under-hood and industrial control environments |
Pinout & Package
Package: SMA (DO-214AC), surface-mount, void-free thermosetting epoxy case with cathode band marking; weight ≈0.3 g; ROHS-compliant matte-tin plating on axial leads.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current sink during forward conduction | Connected to lower-potential node (e.g., GND or return path) in clamping configuration |
| Cathode | Current source during reverse breakdown | Connected to protected line (e.g., VCC or signal) to clamp transients above 16 V |
Key Features
| Feature | Design Value |
|---|---|
| 5% Zener voltage tolerance | Ensures tighter clamping accuracy vs. 10% variants, reducing design margin overhead |
| 285 A peak surge rating | Meets IEC 61000-4-5 Level 4 surge immunity requirements for industrial interfaces |
| 25 °C/W junction-to-lead thermal resistance | Enables direct PCB copper pour heat sinking without external heatsink in space-constrained designs |
| ROHS-compliant matte-tin plating | Guarantees consistent wetting and intermetallic formation per MIL-STD-750 Method 2026 |
Applications
| Automotive Power Rail Protection | Industrial Sensor Signal Line Clamping |
|---|---|
Use Scenario: Suppressing load-dump transients on 12 V battery-fed ECUs in passenger vehicles. IC Role / Device Role / Timing Role: Unidirectional TVS diode placed between VBAT and GND to clamp spikes up to 35 V. Use Value: 16 V breakdown with 285 A surge rating prevents damage to downstream LDOs and microcontrollers during alternator field collapse. | Use Scenario: Protecting analog output lines of pressure sensors in PLC I/O modules. IC Role / Device Role / Timing Role: Zener-based shunt clamp on 4–20 mA current loop outputs against ESD and cable coupling. Use Value: Low 0.25 µA leakage at 12.2 V preserves loop accuracy while 16 Ω dynamic impedance minimizes voltage error during fault events. |
| Consumer USB Port ESD Suppression | Telecom DSL Line Transient Guarding |
Use Scenario: Secondary-level ESD protection on VBUS line of USB 2.0 host ports in set-top boxes. IC Role / Device Role / Timing Role: Standoff diode in series with TVS array to limit let-through energy to IC-level protectors. Use Value: 16 V clamping threshold avoids interference with 5 V USB signaling while 2.0 W rating handles multiple contact discharges. | Use Scenario: Front-end transient suppression on twisted-pair DSL line interface cards. IC Role / Device Role / Timing Role: Primary shunt protector on line-side transformer secondary windings. Use Value: 150°C max storage temperature and DO-214AC mechanical robustness support long-term reliability in outdoor telecom cabinets. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4745A | Same 16 V nominal Zener voltage but in DO-41 through-hole package; 1.0 W rating; higher RθJA | Requires PCB through-hole mounting and larger board area; unsuitable for automated SMT assembly | Select when legacy through-hole design or manual repair is required |
| SMBJ4745A | Same electrical specs but in SMB (DO-214AA) package; 600 W peak pulse power; 1.0 W average | Higher surge capacity but lower thermal resistance (15 °C/W); larger footprint than SMA | Select when higher single-pulse energy handling is needed and board space permits |
Compared with 1N4745A and SMBJ4745A, the SMAJ4745AE3/TR13 offers optimal balance of SMT compatibility, 2.0 W steady-state dissipation, and 285 A surge rating in the smallest standardized surface-mount Zener outline (SMA), making it preferred for high-density consumer and automotive electronics where thermal management and layout efficiency are critical.
Availability
SMAJ4745AE3/TR13 is available at Aetrix Electronics and suitable for automotive power rail protection, industrial sensor signal line clamping, and consumer USB port ESD suppression requiring stable component supply and full traceability.
Supply support for SMAJ4745AE3/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, with ISO 9001-certified production and global distribution.
The SMAJ47xxA series was designed specifically for surface-mount transient voltage suppression in space-constrained, high-reliability applications across automotive, industrial, and telecom sectors, emphasizing tight voltage tolerance, repeatable surge performance, and ROHS compliance.
FAQ
What is the Zener voltage tolerance of SMAJ4745AE3/TR13?
The SMAJ4745AE3/TR13 has a ±5% Zener voltage tolerance, meaning its breakdown voltage is guaranteed between 15.2 V and 16.8 V at 15.5 mA test current. This tighter tolerance compared to non-A suffix variants improves clamping precision in sensitive power rail protection circuits and reduces design safety margins. The 'A' suffix in SMAJ4745AE3/TR13 explicitly denotes this 5% specification per the manufacturer's datasheet.
Does SMAJ4745AE3/TR13 meet ROHS requirements?
Yes, SMAJ4745AE3/TR13 uses ROHS-compliant annealed matte-tin plating on its terminals, verified per MIL-STD-750 Method 2026 for solderability and intermetallic formation. The device carries full ROHS certification documentation from SM Semiconductors, and its void-free thermosetting epoxy body meets UL94V-0 flammability standards - confirming compliance for use in environmentally regulated markets including EU and China RoHS.
What is the maximum surge current rating for SMAJ4745AE3/TR13?
The SMAJ4745AE3/TR13 is rated for 285 A peak surge current (Izsm), measured using a 1/2 sine-wave pulse of 1/120 second duration at 25°C ambient. This value corresponds to the highest surge level in its family and reflects its capability to absorb transient energy from inductive load switching or lightning-induced surges without failure, provided proper PCB thermal relief is implemented.
How does the thermal resistance of SMAJ4745AE3/TR13 affect PCB layout?
The SMAJ4745AE3/TR13 has a junction-to-lead thermal resistance (RθJL) of 25 °C/W, meaning each watt of dissipated power raises the junction temperature by 25°C above lead temperature. To maintain safe operation, designers must provide adequate copper pour connected to both leads - especially the cathode - and avoid narrow traces. This parameter directly dictates minimum pad size and thermal via count in high-duty-cycle clamping applications.
Can SMAJ4745AE3/TR13 be used as a voltage reference?
While SMAJ4745AE3/TR13 provides stable Zener regulation over broad current and temperature ranges, it is not optimized as a precision voltage reference due to relatively high dynamic impedance (16.0 Ω) and ±5% initial tolerance. It functions reliably as a clamping element in TVS applications but lacks the low tempco, low noise, and tight long-term stability required for analog reference circuits. For reference use, dedicated bandgap or buried-Zener ICs are recommended instead of SMAJ4745AE3/TR13.
SMAJ4745AE3/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):
- 16 V
- Tolerance:
- ±5%
- Power - Max:
- 2 W
- Impedance (Max) (Zzt):
- 16 Ohms
- Current - Reverse Leakage @ Vr:
- 5 µA @ 12.2 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
SMAJ4745AE3/TR13 FAQ
1.How can I place an order for SMAJ4745AE3/TR13 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ4745AE3/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 SMAJ4745AE3/TR13 reliable?
The price and inventory of SMAJ4745AE3/TR13 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ4745AE3/TR13 is usually 5 days.
3.What payment methods are accepted for SMAJ4745AE3/TR13?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ4745AE3/TR13 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ4745AE3/TR13?
SMAJ4745AE3/TR13 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ4745AE3/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 SMAJ4745AE3/TR13?
For technical support, including SMAJ4745AE3/TR13 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ4745AE3/TR13 requirements.
6.How does Aetrix verify that SMAJ4745AE3/TR13 is sourced from the original manufacturer or authorized distributors?
All SMAJ4745AE3/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 SMAJ4745AE3/TR13 meets industry standards.
7.What is the process for return or replacement of SMAJ4745AE3/TR13?
All SMAJ4745AE3/TR13 units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ4745AE3/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 SMAJ4745AE3/TR13 part is unused and in its original packaging.
Return procedure for SMAJ4745AE3/TR13:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ4745AE3/TR13 Tags
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