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Microchip Technology SMAJ4742CE3/TR13
- Part No.:
- SMAJ4742CE3/TR13
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ4742CE3/TR13.pdf
- Description:
- DIODE ZENER 12V 2W DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:7,830
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Product details
Overview
SMAJ4742CE3/TR13 from SM Semiconductor is a 12 V, 2% tolerance Zener diode in SMA (DO-214AC) package, rated for 2.0 W steady-state power dissipation, 152 mA maximum regulator current at 100°C, and 380 A peak surge current; used for precision voltage regulation and transient suppression in power rails of industrial sensor interfaces.
For engineers reviewing the SMAJ4742CE3/TR13 datasheet, SMAJ4742CE3/TR13 pinout, SMAJ4742CE3/TR13 application, or SMAJ4742CE3/TR13 equivalent, key selection criteria include zener voltage tolerance (2%), thermal resistance (25 °C/W), reverse leakage (5 µA @ 9.1 V), surge capability (380 A), and ROHS-compliant matte-tin plating for reliable solderability.
Technical Context
This device operates as a silicon planar Zener diode with sharp breakdown knee, specified for stable regulation across 10 µA to 152 mA operating current range and -65 °C to +150 °C temperature envelope. Its 2% voltage tolerance (C suffix) and low dynamic impedance (9 Ω @ 21 mA) enable tight reference stability in feedback loops and protection circuits.
The SMAJ4742CE3/TR13 features void-free thermosetting epoxy encapsulation (UL94V-0), cathode band polarity marking, and 0.3 g mass. It is designed for axial-lead mounting with thermal performance optimized for lead-to-junction conduction, not PCB pad heatsinking.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage | 12.0 V ±2% at 21 mA test current - ensures precise clamping threshold for 12 V rail protection |
| Power Dissipation | 2.0 W steady-state - supports continuous regulation without forced cooling in compact layouts |
| Dynamic Impedance | 9.0 Ω @ 21 mA - minimizes output voltage deviation under varying load current |
| Reverse Leakage | 5 µA @ 9.1 V - guarantees low standby power loss in always-on sensing circuits |
| Surge Current | 380 A (1/2 sine wave, 1/120 s) - withstands high-energy transients from inductive switching |
| Thermal Resistance | 25 °C/W junction-to-lead - enables accurate thermal design using lead as primary heat path |
| Operating Temp | -65 °C to +150 °C - qualified for under-hood automotive and industrial ambient extremes |
Pinout & Package
Package: SMA (DO-214AC), surface-mount compatible axial-lead outline with cathode band marking; body marked with part number; tin-lead or ROHS-compliant matte-tin plating.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / low-side reference node | Connected to circuit ground or lower-potential rail during regulation |
| Cathode | Zener breakdown terminal / regulated output node | Connected to protected line; clamps voltage to 12.0 V when reverse-biased beyond breakdown |
Key Features
| Feature | Design Value |
|---|---|
| 2% Zener voltage tolerance | Enables use in precision reference applications where ±240 mV absolute accuracy at 12 V is required |
| 152 mA max regulator current at 100°C | Supports sustained clamp operation under elevated ambient without derating in sealed enclosures |
| UL94V-0 void-free epoxy case | Provides flame-retardant mechanical integrity and moisture resistance for long-term reliability |
| ROHS-compliant matte-tin plating | Ensures consistent wetting and intermetallic formation during reflow or hand-soldering per MIL-STD-750 |
Applications
| Industrial Sensor Signal Protection | Automotive Body Control Module Power Rail |
|---|---|
Use Scenario: Protecting analog output lines of pressure/temperature sensors from ESD and load-dump transients in factory automation PLC I/O modules. IC Role / Device Role / Timing Role: Zener clamp placed between signal line and ground to limit excursion to ≤12.24 V (12 V + 2%). Use Value: Prevents ADC input saturation and op-amp latch-up while maintaining signal fidelity below 12 V nominal range. | Use Scenario: Suppressing 12 V battery rail spikes caused by alternator load dump or relay coil de-energization in BCM power distribution networks. IC Role / Device Role / Timing Role: Parallel-connected transient voltage suppressor absorbing >380 A surge energy within 1/120 second. Use Value: Limits rail overvoltage to 12.24 V, protecting downstream MCU, CAN transceivers, and driver ICs from permanent damage. |
| Telecom Line Interface Protection | Computer Peripheral Power Sequencing |
Use Scenario: Safeguarding RS-485 transceiver VCC pins against induced surges on long cable runs in building management systems. IC Role / Device Role / Timing Role: Low-impedance shunt regulator referenced to local ground, activated only during overvoltage events. Use Value: Maintains <5 µA leakage during normal operation while clamping transients faster than TVS diodes with higher capacitance. | Use Scenario: Stabilizing 12 V auxiliary supply during hot-plug insertion of PCIe add-in cards in server backplanes. IC Role / Device Role / Timing Role: Precision voltage reference for supervisor IC reset thresholds and power-good monitoring. Use Value: Delivers ±2% regulation over -40 °C to +85 °C, eliminating need for external trimming resistors. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4742A | 10% voltage tolerance (vs. 2%); same 12 V nominal, 1 W rating, DO-41 package | Lower cost for non-critical biasing; unsuitable for precision references or tight-clamp protection | Select when ±1.2 V tolerance is acceptable and through-hole mounting is preferred |
| BZX84-C12 | 2% tolerance, but SOT-23 package, 300 mW rating, 100 mA max current | Limited surge handling (100 A typical); intended for low-power signal-level clamping | Choose for space-constrained PCBs where 380 A surge immunity is not required |
Compared with 1N4742A and BZX84-C12, the SMAJ4742CE3/TR13 uniquely combines 2% tolerance, 2.0 W power, 380 A surge rating, and SMA package - making it the only option qualified for high-reliability 12 V rail protection in industrial and automotive environments requiring both precision and robustness.
Availability
SMAJ4742CE3/TR13 is available at Aetrix Electronics and suitable for industrial sensor interfaces, automotive body control modules, telecom line protection, and computer peripheral power sequencing requiring stable component supply and long-term lifecycle support.
Supply support for SMAJ4742CE3/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 consumer applications.
The SMAJ47xxA series is engineered for high-density transient voltage suppression and precision DC voltage regulation in harsh environments, with emphasis on thermal robustness, surge resilience, and tight parametric control.
FAQ
What is the zener voltage tolerance of SMAJ4742CE3/TR13?
The SMAJ4742CE3/TR13 has a 2% zener voltage tolerance, meaning its breakdown voltage is guaranteed between 11.76 V and 12.24 V at 21 mA test current. This tighter tolerance is indicated by the "C" suffix and distinguishes it from standard 10% parts like SMAJ4742A. The SMAJ4742CE3/TR13 is therefore suitable for applications demanding higher regulation accuracy.
What is the maximum surge current rating for SMAJ4742CE3/TR13?
The SMAJ4742CE3/TR13 is rated for 380 A peak surge current using a 1/2 sine wave pulse of 1/120 second duration, measured at 25°C ambient. This value reflects its capability to absorb high-energy transients common in automotive load-dump and industrial inductive switching events without failure.
Is SMAJ4742CE3/TR13 RoHS compliant?
Yes, SMAJ4742CE3/TR13 uses ROHS-compliant annealed matte-tin plating on its terminals, meeting JEDEC and MIL-STD-750 solderability requirements. The device is fully compliant with EU RoHS Directive 2011/65/EU and contains no lead, mercury, cadmium, hexavalent chromium, PBB, or PBDE above threshold limits.
What package type does SMAJ4742CE3/TR13 use?
SMAJ4742CE3/TR13 uses the SMA (DO-214AC) package - a surface-mountable, axial-lead outline with molded thermosetting epoxy body (UL94V-0 rated). Its dimensions are standardized per JEDEC DO-214AC, and polarity is indicated by a cathode band on the body.
How does the thermal resistance of SMAJ4742CE3/TR13 affect PCB layout?
The SMAJ4742CE3/TR13 has a junction-to-lead thermal resistance of 25 °C/W, meaning heat is primarily conducted through the leads rather than the PCB pads. Layout should prioritize wide, low-thermal-resistance copper traces connected directly to both anode and cathode leads - not rely on thermal vias alone - to maintain safe junction temperatures under sustained 2.0 W dissipation.
SMAJ4742CE3/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):
- 12 V
- Tolerance:
- ±2%
- Power - Max:
- 2 W
- Impedance (Max) (Zzt):
- 9 Ohms
- Current - Reverse Leakage @ Vr:
- 5 µA @ 9.1 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
SMAJ4742CE3/TR13 FAQ
1.How can I place an order for SMAJ4742CE3/TR13 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ4742CE3/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 SMAJ4742CE3/TR13 reliable?
The price and inventory of SMAJ4742CE3/TR13 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ4742CE3/TR13 is usually 5 days.
3.What payment methods are accepted for SMAJ4742CE3/TR13?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ4742CE3/TR13 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ4742CE3/TR13?
SMAJ4742CE3/TR13 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ4742CE3/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 SMAJ4742CE3/TR13?
For technical support, including SMAJ4742CE3/TR13 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ4742CE3/TR13 requirements.
6.How does Aetrix verify that SMAJ4742CE3/TR13 is sourced from the original manufacturer or authorized distributors?
All SMAJ4742CE3/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 SMAJ4742CE3/TR13 meets industry standards.
7.What is the process for return or replacement of SMAJ4742CE3/TR13?
All SMAJ4742CE3/TR13 units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ4742CE3/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 SMAJ4742CE3/TR13 part is unused and in its original packaging.
Return procedure for SMAJ4742CE3/TR13:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ4742CE3/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
onsemi
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SMAJ4744A-TP
Micro Commercial Co
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BZT52C3V6LP-7
Diodes Incorporated
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SMAZ12-13-F
Diodes Incorporated
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