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Microchip Technology SMAJ4738CE3/TR13
- Part No.:
- SMAJ4738CE3/TR13
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ4738CE3/TR13.pdf
- Description:
- DIODE ZENER 8.2V 2W DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:3,601
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Product details
Overview
SMAJ4738CE3/TR13 from SM Semiconductors is a 8.2 V, ±2% tolerance Zener diode in SMA (DO-214AC) package, rated for 2.0 W steady-state power dissipation, 220 mA maximum regulator current at 100°C, and 550 A peak surge current; used for precision voltage regulation and transient overvoltage protection in low-profile DC power rails.
For engineers reviewing the SMAJ4738CE3/TR13 datasheet, SMAJ4738CE3/TR13 pinout, SMAJ4738CE3/TR13 application, or SMAJ4738CE3/TR13 equivalent, key selection criteria include zener voltage tolerance (±2%), thermal resistance (25 °C/W), reverse leakage (≤10 µA @ 6.0 V), surge current capability (550 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 and stable regulation across 0.25–31 mA test current range. Its 8.2 V nominal zener voltage is specified at 31 mA (IZT), with dynamic impedance ≤4.5 Ω and knee impedance ≤0.5 Ω at 0.25 mA (IZK).
Designed for unidirectional transient voltage suppression, it features cathode-band polarity marking, void-free thermosetting epoxy case (UL94V-0), and junction-to-lead thermal resistance of 25 °C/W-enabling effective heat conduction to PCB copper when lead-soldered.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage VZ | 8.2 V ±2% at 31 mA - ensures tight regulation tolerance for reference and clamp circuits |
| Power Dissipation PM(AV) | 2.0 W - supports continuous operation in compact layouts with adequate copper heatsinking |
| Max Regulator Current IZM | 220 mA at TJ = 100°C - defines safe DC current limit under thermal equilibrium |
| Peak Surge Current Izsm | 550 A - withstands 1/2-sine 120 Hz transients per MIL-STD-750 Method 3013 |
| Reverse Leakage IR | ≤10 µA @ VR = 6.0 V - guarantees low standby power loss in high-impedance bias networks |
| Dynamic Impedance ZZT | ≤4.5 Ω @ IZT = 31 mA - minimizes output voltage variation under load current changes |
| Thermal Resistance RθJL | 25 °C/W - enables direct thermal path from junction to PCB via leads, critical for reliability |
Pinout & Package
Package: SMA (DO-214AC), surface-mount, cathode indicated by band, ROHS-compliant matte-tin plated leads, 0.3 g typical weight.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / low-side reference node | Connected to circuit ground or lower potential; forms regulated reference when reverse-biased |
| Cathode | Zener breakdown terminal / clamping node | Connected to protected line; conducts during overvoltage to clamp voltage at 8.2 V ±2% |
Key Features
| Feature | Design Value |
|---|---|
| ±2% Zener voltage tolerance | Enables precise voltage referencing without external trimming in analog sensor biasing and ADC reference circuits |
| 25 °C/W junction-to-lead thermal resistance | Allows direct thermal coupling to PCB copper pour, supporting 2.0 W operation without heatsink in space-constrained designs |
| UL94V-0 void-free epoxy case | Provides flame-retardant mechanical integrity and moisture resistance for industrial and automotive under-hood applications |
| ROHS-compliant matte-tin plating | Ensures consistent wetting and intermetallic formation during reflow, meeting IPC-J-STD-006B solderability requirements |
Applications
| Industrial Sensor Signal Conditioning | Automotive Body Control Module (BCM) Power Rail Clamp |
|---|---|
Use Scenario: Protecting 3.3 V/5 V analog front-end inputs of temperature and pressure sensors from ESD and load-dump transients. IC Role / Device Role / Timing Role: Unidirectional Zener clamp placed between signal line and ground, activated above 8.2 V. Use Value: Limits transient overshoot to ≤8.4 V (max), preserving ADC input integrity and preventing latch-up in downstream op-amps. | Use Scenario: Clamping 12 V supply rail in BCM microcontroller power domain during alternator load dump events. IC Role / Device Role / Timing Role: Primary overvoltage suppressor on main VDD rail, triggered within nanoseconds of voltage excursion. Use Value: Absorbs up to 550 A surge energy while holding rail voltage below 10.0 V for ≥100 ms, satisfying ISO 7637-2 Pulse 5a immunity. |
| Consumer USB-C Power Delivery Interface Protection | Telecom DSL Line Card Transient Suppression |
Use Scenario: Safeguarding USB-C CC logic lines and VCONN supply against hot-plug induced transients and ESD. IC Role / Device Role / Timing Role: Low-capacitance Zener clamp referenced to system ground, placed adjacent to connector. Use Value: Maintains <10 µA leakage at 5.0 V, ensuring compliance with USB PD v2.0 quiescent current limits while clamping >8.2 V spikes. | Use Scenario: Protecting ADSL/VDLS line driver ICs from lightning-induced surges on twisted-pair telephone lines. IC Role / Device Role / Timing Role: Secondary protection stage after gas discharge tube (GDT), providing fast-response clamping. Use Value: Delivers 550 A surge rating with ≤4.5 Ω dynamic impedance, minimizing let-through voltage to preserve line driver SOA. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation and transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4738A-T | 10% voltage tolerance (8.2 V ±10%), DO-41 package, higher RθJA (65 °C/W), 1.0 W rating | Lower precision, axial-lead mounting, reduced surge capacity (100 A) | Acceptable where cost sensitivity outweighs tolerance and surge requirements |
| BZX84-C8V2LT1G | ±5% tolerance, SOT-23 package, 350 mW rating, 100 mA IZM, 200 A Izsm | Smaller footprint but lower power handling; unsuitable for >150 mA continuous loads | Preferred for space-constrained low-power bias networks, not for rail clamping |
Compared with SMAJ4738CE3/TR13, 1N4738A-T offers lower cost but sacrifices precision and surge robustness, while BZX84-C8V2LT1G saves board area at the expense of thermal performance and clamping energy absorption-making SMAJ4738CE3/TR13 optimal for high-reliability 2.0 W transient suppression.
Availability
SMAJ4738CE3/TR13 is available at Aetrix Electronics and suitable for industrial sensor interfaces, automotive body control modules, consumer USB-C power delivery protection, and telecom line card transient suppression requiring stable component supply and long-term manufacturability.
Supply support for SMAJ4738CE3/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 designed specifically for high-density, surface-mount transient voltage suppression and precision DC voltage regulation in space-constrained, thermally demanding environments.
FAQ
What is the zener voltage tolerance of SMAJ4738CE3/TR13?
The SMAJ4738CE3/TR13 has a zener voltage tolerance of ±2%, indicated by the "C" suffix in its part number. This means its breakdown voltage is guaranteed between 8.04 V and 8.36 V at 31 mA test current and 25°C ambient. That tight tolerance supports precision regulation tasks such as reference voltage generation and analog sensor biasing where stability is critical. The SMAJ4738CE3/TR13 achieves this via tighter process control during wafer fabrication and post-package screening.
Does SMAJ4738CE3/TR13 meet ROHS requirements?
Yes, SMAJ4738CE3/TR13 complies with ROHS Directive 2011/65/EU. Its terminals feature ROHS-compliant annealed matte-tin plating, verified per MIL-STD-750 Method 2026 for solderability, and its void-free thermosetting epoxy case meets UL94V-0 flammability standards. No lead, mercury, cadmium, hexavalent chromium, PBB, or PBDE substances exceed threshold limits. The SMAJ4738CE3/TR13 is suitable for use in consumer, industrial, and automotive electronics requiring full environmental compliance.
What is the maximum surge current rating for SMAJ4738CE3/TR13?
The SMAJ4738CE3/TR13 is rated for a peak surge current (Izsm) of 550 A, measured using a 1/2 sine wave pulse of 120 Hz frequency and 1/120 second duration at 25°C ambient. This rating reflects its ability to absorb transient energy from inductive switching or lightning-induced surges without failure. The SMAJ4738CE3/TR13 achieves this through optimized silicon geometry and low thermal resistance (25 °C/W), enabling rapid heat dissipation into the PCB leads during short-duration events.
Can SMAJ4738CE3/TR13 be used in place of SMAJ4738A?
No-SMAJ4738CE3/TR13 and SMAJ4738A are not interchangeable without verification. SMAJ4738A has ±10% tolerance and no ROHS compliance guarantee, while SMAJ4738CE3/TR13 specifies ±2% tolerance and ROHS-compliant plating. Their packaging differs: SMAJ4738CE3/TR13 is supplied in TR13 tape-and-reel format with moisture-sensitive level (MSL) 1 handling, whereas SMAJ4738A may ship in bulk or different reel configurations. Always validate layout, thermal design, and qualification testing before substituting SMAJ4738CE3/TR13 for SMAJ4738A.
What is the thermal resistance junction-to-lead for SMAJ4738CE3/TR13?
The thermal resistance junction-to-lead (RθJL) for SMAJ4738CE3/TR13 is 25 °C/W, meaning each watt of power dissipated raises the junction temperature 25°C above the lead temperature. This value is measured under standardized conditions per JEDEC JESD51-14 and assumes proper soldering to ≥1 cm² of 1 oz copper. It directly determines the maximum continuous current (220 mA at 100°C) and validates the SMAJ4738CE3/TR13's suitability for 2.0 W operation in thermally managed PCB layouts.
SMAJ4738CE3/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):
- 8.2 V
- Tolerance:
- ±2%
- Power - Max:
- 2 W
- Impedance (Max) (Zzt):
- 4.5 Ohms
- Current - Reverse Leakage @ Vr:
- 10 µA @ 6 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
SMAJ4738CE3/TR13 FAQ
1.How can I place an order for SMAJ4738CE3/TR13 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ4738CE3/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 SMAJ4738CE3/TR13 reliable?
The price and inventory of SMAJ4738CE3/TR13 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ4738CE3/TR13 is usually 5 days.
3.What payment methods are accepted for SMAJ4738CE3/TR13?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ4738CE3/TR13 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ4738CE3/TR13?
SMAJ4738CE3/TR13 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ4738CE3/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 SMAJ4738CE3/TR13?
For technical support, including SMAJ4738CE3/TR13 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ4738CE3/TR13 requirements.
6.How does Aetrix verify that SMAJ4738CE3/TR13 is sourced from the original manufacturer or authorized distributors?
All SMAJ4738CE3/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 SMAJ4738CE3/TR13 meets industry standards.
7.What is the process for return or replacement of SMAJ4738CE3/TR13?
All SMAJ4738CE3/TR13 units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ4738CE3/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 SMAJ4738CE3/TR13 part is unused and in its original packaging.
Return procedure for SMAJ4738CE3/TR13:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ4738CE3/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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