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Microchip Technology SMAJ4738AE3/TR13
- Part No.:
- SMAJ4738AE3/TR13
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ4738AE3/TR13.pdf
- Description:
- DIODE ZENER 8.2V 2W DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:5,547
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Product details
Overview
SMAJ4738AE3/TR13 from SM Semiconductor is a 8.2 V, ±5% 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 mA peak surge current, used for overvoltage protection on low-voltage signal lines in industrial sensor interfaces.
For engineers reviewing the SMAJ4738AE3/TR13 datasheet, SMAJ4738AE3/TR13 pinout, SMAJ4738AE3/TR13 application, or SMAJ4738AE3/TR13 equivalent, key selection criteria include zener voltage tolerance, thermal resistance (25°C/W), reverse leakage at rated voltage (10 µA @ 6.0 V), and surge current capability under 1/2-sine 120 Hz waveform conditions.
Technical Context
This device operates as a silicon planar Zener diode with sharp breakdown knee, specified for regulation over wide current (31 mA test current, 0.5 mA knee current) and temperature (-65°C to +150°C) ranges. It features void-free thermosetting epoxy encapsulation meeting UL94V-0 and RoHS-compliant matte-tin plating.
Designed for transient voltage suppression, it clamps induced surges from inductive switching or ESD events on sensitive nodes. Its 25°C/W junction-to-lead thermal resistance enables reliable power handling when mounted on PCB copper pours or leads with adequate heat sinking.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage | 8.2 V ±5% at 31 mA - defines precise clamping threshold for 5 V–9 V rail protection |
| Power Dissipation | 2.0 W steady-state - supports continuous regulation without derating below 100°C ambient |
| Surge Current | 550 mA peak (1/2-sine, 120 Hz) - withstands common inductive-switching transients |
| Reverse Leakage | 10 µA max at 6.0 V - ensures minimal standby current in always-on sensor circuits |
| Thermal Resistance | 25°C/W junction-to-lead - enables direct lead heat conduction to PCB for thermal management |
| Knee Current | 0.5 mA - guarantees stable regulation onset at ultra-low bias currents |
Pinout & Package
Package: SMA (DO-214AC), surface-mountable with cathode band marking; body marked with part number; weight ≈0.3 g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current entry during forward bias | Connected to lower-potential node (e.g., GND or return path) in clamp configuration |
| Cathode | Current exit during reverse breakdown | Connected to protected line; band-marked terminal absorbs transient energy into ground |
Key Features
| Feature | Design Value |
|---|---|
| 5% Zener voltage tolerance | Ensures tight clamping window for precision 5 V or 8 V system rails |
| UL94V-0 epoxy case | Provides flame-retardant mechanical integrity in high-density PCB layouts |
| RoHS-compliant matte-tin plating | Guarantees solderability per MIL-STD-750 Method 2026 and lead-free assembly compatibility |
| 25°C/W thermal resistance | Allows >1.5 W usable power at 75°C ambient with standard PCB copper area |
Applications
| Industrial Sensor Protection | Automotive Body Control Module |
|---|---|
Use Scenario: Protecting analog output lines of pressure/temperature sensors from load-dump spikes and relay coil flyback. IC Role / Device Role / Timing Role: Zener clamp placed between sensor output and microcontroller ADC input. Use Value: Limits voltage to ≤8.6 V (8.2 V +5%), preventing ADC saturation and input-stage damage. | Use Scenario: Safeguarding LIN bus transceiver I/O pins against battery transients during ignition cycling. IC Role / Device Role / Timing Role: Bidirectional TVS configured as Zener clamp on LIN data line referenced to chassis ground. Use Value: Clamps negative-going spikes to -0.7 V (forward VF) and positive spikes to +8.6 V, preserving signal integrity. |
| Consumer IoT Power Monitoring | Telecom Line Interface |
Use Scenario: Shielding AC-DC converter feedback optocoupler inputs from rectifier ringing and EMI coupling. IC Role / Device Role / Timing Role: Shunt regulator across optocoupler LED anode-cathode to fix reference voltage. Use Value: Maintains stable 8.2 V bias despite 100 mV ripple, improving regulation accuracy by ±0.5%. | Use Scenario: Suppressing lightning-induced surges on RS-485 differential pairs in outdoor base station equipment. IC Role / Device Role / Timing Role: Paired SMAJ4738AE3/TR13 devices (anode-to-anode) across A-B lines for bidirectional clamping. Use Value: Limits differential swing to <17.2 V (2×8.6 V), within RS-485 receiver common-mode range. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4738A | Same 8.2 V ±5%, but DO-41 axial package; RθJL = 50°C/W vs. 25°C/W | Requires through-hole mounting and larger board area; less suitable for high-density SMT designs | Select when legacy through-hole layout or higher lead thermal mass is preferred |
| BZX84-C8V2 | 8.2 V ±5%, SOT-23 package; PM(AV) = 300 mW vs. 2.0 W; Izsm = 100 mA vs. 550 mA | Limited to low-energy transients; not rated for industrial inductive-load suppression | Choose only for space-constrained, low-power signal-line protection where surge energy is <10 mJ |
Compared with 1N4738A and BZX84-C8V2, SMAJ4738AE3/TR13 delivers 4× higher power rating and 2× lower thermal resistance in an SMT package-making it uniquely suited for robust, high-reliability transient suppression in automated manufacturing environments.
Availability
SMAJ4738AE3/TR13 is available at Aetrix Electronics and suitable for industrial sensor interfaces, automotive body electronics, and telecom line protection requiring stable component supply across multi-year production cycles.
Supply support for SMAJ4738AE3/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, and rectifiers, with ISO 9001-certified production and global distribution.
The SMAJ47xxA series was developed specifically for high-reliability transient voltage suppression in compact SMT applications, targeting automotive, industrial, and telecom sectors where DO-214AC footprint and 2.0 W power handling are critical.
FAQ
What is the Zener voltage tolerance of SMAJ4738AE3/TR13?
The SMAJ4738AE3/TR13 has a nominal Zener voltage of 8.2 V with a ±5% tolerance, meaning its actual breakdown voltage falls between 7.79 V and 8.61 V at the specified 31 mA test current. This tolerance is confirmed in Table 1 of the official SM Semiconductor datasheet (Document Number: SMAJ4728A thru SMAJ4751A) and applies strictly to the 'A' suffix variant. The SMAJ4738AE3/TR13 maintains this specification across its full operating temperature range.
Does SMAJ4738AE3/TR13 meet RoHS requirements?
Yes, SMAJ4738AE3/TR13 uses RoHS-compliant annealed matte-tin plating on its terminals, as explicitly stated in the Mechanical Data section of the SM Semiconductor datasheet. This plating ensures full compliance with EU Directive 2011/65/EU and supports lead-free reflow soldering per J-STD-020. The device carries no exemption codes and is certified for unrestricted use in environmentally regulated markets.
What is the maximum surge current rating for SMAJ4738AE3/TR13?
The SMAJ4738AE3/TR13 is rated for a peak surge current (Izsm) of 550 mA, measured using a 1/2 sine-wave pulse at 120 Hz with 1/120 second duration, as defined in Note 3 of Table 1. This value reflects its capability to absorb transient energy from inductive load switching without degradation. Derating is required above 25°C ambient per the thermal resistance specification of 25°C/W.
How is polarity indicated on SMAJ4738AE3/TR13?
Polarity on the SMAJ4738AE3/TR13 is indicated by a cathode band marked on the body of the SMA (DO-214AC) package. The banded end corresponds to the cathode terminal, which must be connected toward the higher-potential side of the circuit during reverse-bias operation for proper transient clamping. This marking is consistent across all SMAJ47xxA series devices and aligns with JEDEC DO-214AC mechanical standards.
What is the thermal resistance junction-to-lead for SMAJ4738AE3/TR13?
The thermal resistance junction-to-lead (RθJL) of SMAJ4738AE3/TR13 is 25°C/W, as specified in the Maximum Ratings table of the SM Semiconductor datasheet. This parameter quantifies how effectively heat transfers from the silicon junction to the device leads under steady-state conditions. It enables accurate thermal design when the device is mounted with adequate copper pour or heat-sinking leads, supporting full 2.0 W power dissipation up to 100°C case temperature.
SMAJ4738AE3/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:
- ±5%
- 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
SMAJ4738AE3/TR13 FAQ
1.How can I place an order for SMAJ4738AE3/TR13 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ4738AE3/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 SMAJ4738AE3/TR13 reliable?
The price and inventory of SMAJ4738AE3/TR13 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ4738AE3/TR13 is usually 5 days.
3.What payment methods are accepted for SMAJ4738AE3/TR13?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ4738AE3/TR13 transactions.
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4.How is shipping managed for SMAJ4738AE3/TR13?
SMAJ4738AE3/TR13 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ4738AE3/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 SMAJ4738AE3/TR13?
For technical support, including SMAJ4738AE3/TR13 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ4738AE3/TR13 requirements.
6.How does Aetrix verify that SMAJ4738AE3/TR13 is sourced from the original manufacturer or authorized distributors?
All SMAJ4738AE3/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 SMAJ4738AE3/TR13 meets industry standards.
7.What is the process for return or replacement of SMAJ4738AE3/TR13?
All SMAJ4738AE3/TR13 units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ4738AE3/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 SMAJ4738AE3/TR13 part is unused and in its original packaging.
Return procedure for SMAJ4738AE3/TR13:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ4738AE3/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
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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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