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Microchip Technology SMAJ4746CE3/TR13
- Part No.:
- SMAJ4746CE3/TR13
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ4746CE3/TR13.pdf
- Description:
- DIODE ZENER 18V 2W DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:7,296
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Product details
Overview
SMAJ4746CE3/TR13 from SM Semiconductors is a 18 V, 5% tolerance Zener diode in SMA (DO-214AC) package, rated for 2.0 W steady-state power dissipation, 14.0 Ω dynamic impedance at 14.0 mA test current, and 100 mA maximum regulator current at 100°C junction temperature-used for precision voltage regulation and transient suppression in low-profile power rails.
For engineers reviewing the SMAJ4746CE3/TR13 datasheet, SMAJ4746CE3/TR13 pinout, SMAJ4746CE3/TR13 application, or SMAJ4746CE3/TR13 equivalent, key selection criteria include zener voltage tolerance (±5%), thermal resistance (25°C/W), surge current capability (250 A), reverse leakage (≤5 µA at 13.7 V), 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 over wide current (1.0–100 mA) and temperature (−65°C to +150°C) ranges. It uses void-free thermosetting epoxy encapsulation meeting UL94V-0 and features cathode band polarity marking.
Designed for unidirectional transient voltage suppression and DC voltage reference, it delivers 18.0 V nominal breakdown at 14.0 mA (IZT), with 20.0 Ω maximum knee impedance at 0.25 mA (IZK) and ≤5 µA reverse leakage at 13.7 V (VR).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage VZ @ IZT | 18.0 V ±5% at 14.0 mA - defines precise regulation point for feedback or clamp circuits |
| Power Dissipation PM(AV) | 2.0 W - supports continuous operation in compact PCB layouts without forced cooling |
| Dynamic Impedance ZZT | 20.0 Ω max at 14.0 mA - ensures minimal output voltage variation under load transients |
| Surge Current Izsm | 250 A - withstands 1/2-sine 120 Hz surge per IEC 61000-4-5 Level 4 |
| Reverse Leakage IR | ≤5 µA at VR = 13.7 V - guarantees low standby power loss in always-on bias networks |
| Thermal Resistance RθJL | 25 °C/W - enables direct lead-to-PCB heat conduction for thermal reliability |
| Operating Temperature | −65°C to +150°C - qualified for automotive under-hood and industrial control environments |
Pinout & Package
Package: SMA (DO-214AC), surface-mount, axial-lead compatible, void-free UL94V-0 epoxy body, cathode indicated by band, 0.3 g weight.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / low-side reference node | Connected to ground or lower-potential rail in shunt regulator or clamp configuration |
| Cathode | Zener breakdown terminal / regulated output node | Connected to supply rail or signal line requiring overvoltage protection or voltage reference |
Key Features
| Feature | Design Value |
|---|---|
| 5% Zener voltage tolerance | Enables tighter regulation accuracy than 10% variants, reducing need for post-regulation trimming |
| ROHS-compliant matte-tin plating | Ensures consistent wetting and intermetallic formation during reflow, compliant with IPC-J-STD-006 |
| 250 A peak surge rating | Meets IEC 61000-4-5 surge immunity requirements for industrial I/O and sensor interfaces |
| UL94V-0 epoxy encapsulation | Provides flame-retardant mechanical integrity in high-density assemblies exposed to thermal cycling |
| Low thermal resistance (25°C/W) | Allows direct PCB copper pour connection to leads for passive heatsinking without thermal vias |
Applications
| Industrial Sensor Signal Conditioning | Automotive Body Control Module Power Rail |
|---|---|
Use Scenario: Protecting analog front-end inputs of 24 V industrial pressure sensors against inductive switching transients from solenoid drivers. IC Role / Device Role / Timing Role: Shunt Zener clamp placed between signal line and ground, clamping excursions above 18.9 V. Use Value: Prevents ADC saturation and op-amp input stage damage while maintaining <100 ns response due to low junction capacitance. | Use Scenario: Regulating 12 V microcontroller supply in BCM modules subject to load-dump events up to 35 V. IC Role / Device Role / Timing Role: Standby voltage reference and secondary overvoltage limiter downstream of primary TVS array. Use Value: Maintains 18.0 V ±0.9 V regulation across −40°C to +125°C ambient, enabling fail-safe brownout detection. |
| Telecom Line Interface Protection | Consumer Appliance Motor Drive Feedback |
Use Scenario: Safeguarding RS-485 transceiver VCC pins against EFT bursts on telecom base station backplane traces. IC Role / Device Role / Timing Role: Low-leakage (≤5 µA) Zener reference stabilizing local LDO enable threshold. Use Value: Eliminates false resets during 4 kV EFT testing by holding enable logic high until bus voltage exceeds 13.7 V. | Use Scenario: Providing stable 18 V reference for hall-effect rotor position sensing in BLDC motor controllers. IC Role / Device Role / Timing Role: Precision voltage source for comparator hysteresis setting and analog sensor biasing. Use Value: Delivers ±0.9 V regulation accuracy over 100°C temperature swing, ensuring consistent commutation timing. |
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 |
|---|---|---|---|
| 1N4746A | Same 18 V nominal, but 10% tolerance and DO-41 package (larger footprint, higher RθJA) | Less suitable for space-constrained SMT designs; higher thermal resistance limits power handling | Select when through-hole mounting is required and ±10% regulation tolerance is acceptable |
| BZX84-C18 | 18 V, 5% tolerance, but SOT-23 package, 300 mW rating, and 100 Ω typical Zz | Lower surge capacity (100 A) and power derating limit use in high-energy transient environments | Select for ultra-compact bias networks where 250 A surge immunity is not required |
Compared with 1N4746A and BZX84-C18, SMAJ4746CE3/TR13 offers superior surge robustness (250 A), tighter tolerance (±5%), and optimized thermal path (25°C/W) for SMT power rail stabilization-making it preferred for automotive and industrial applications demanding long-term reliability under repeated transients.
Availability
SMAJ4746CE3/TR13 is available at Aetrix Electronics and suitable for industrial sensor conditioning, automotive body control modules, telecom line interface protection, and consumer appliance motor drive feedback requiring stable component supply and traceable sourcing.
Supply support for SMAJ4746CE3/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.
The SMAJ47xxA series targets high-reliability voltage regulation and transient suppression in space-constrained, thermally demanding applications-designed specifically for automotive, industrial, and telecom infrastructure where long-term stability and surge resilience are critical.
FAQ
What is the exact Zener voltage tolerance for SMAJ4746CE3/TR13?
The 'C' suffix in SMAJ4746CE3/TR13 denotes a ±2% Zener voltage tolerance, not ±5%. Per the datasheet note: 'C signifies 2% tolerance'. Therefore, SMAJ4746CE3/TR13 has a breakdown voltage range of 17.64 V to 18.36 V at 14.0 mA test current, verified per Table 1 and footnote 1.
Does SMAJ4746CE3/TR13 meet RoHS and REACH requirements?
Yes, SMAJ4746CE3/TR13 uses ROHS-compliant annealed matte-tin plating on terminals, as explicitly stated in the Mechanical Data section. It conforms to EU RoHS Directive 2011/65/EU and REACH SVHC thresholds, with no intentionally added lead, cadmium, mercury, hexavalent chromium, PBB, or PBDE.
What is the maximum surge current rating for SMAJ4746CE3/TR13 and under what waveform conditions?
SMAJ4746CE3/TR13 is rated for 250 A peak surge current (Izsm), measured using a 1/2 sine wave or equivalent sine wave pulse of 1/120 second duration at 25°C ambient, as defined in Note 3 of Table 1. This corresponds to IEC 61000-4-5 Combination Wave Generator (CWG) Level 4 testing.
How does the thermal resistance of SMAJ4746CE3/TR13 impact PCB layout design?
With RθJL = 25°C/W, SMAJ4746CE3/TR13 relies on efficient heat conduction through its leads. Designers must connect both anode and cathode pads to ≥10 mm² copper pours (2 oz Cu) without thermal relief to achieve rated 2.0 W dissipation. Smaller pads or isolated traces cause >100°C junction rise at full power.
Can SMAJ4746CE3/TR13 be used as a bidirectional transient suppressor?
No. SMAJ4746CE3/TR13 is a unidirectional Zener diode, designed for forward conduction (VF ≤1.2 V at 200 mA) and reverse breakdown only. For bidirectional protection, a pair of SMAJ4746CE3/TR13 devices in series opposition-or a dedicated bidirectional TVS like SMAJ18CA-is required.
SMAJ4746CE3/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):
- 18 V
- Tolerance:
- ±2%
- Power - Max:
- 2 W
- Impedance (Max) (Zzt):
- 20 Ohms
- Current - Reverse Leakage @ Vr:
- 5 µA @ 13.7 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
SMAJ4746CE3/TR13 FAQ
1.How can I place an order for SMAJ4746CE3/TR13 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ4746CE3/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 SMAJ4746CE3/TR13 reliable?
The price and inventory of SMAJ4746CE3/TR13 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ4746CE3/TR13 is usually 5 days.
3.What payment methods are accepted for SMAJ4746CE3/TR13?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ4746CE3/TR13 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ4746CE3/TR13?
SMAJ4746CE3/TR13 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ4746CE3/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 SMAJ4746CE3/TR13?
For technical support, including SMAJ4746CE3/TR13 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ4746CE3/TR13 requirements.
6.How does Aetrix verify that SMAJ4746CE3/TR13 is sourced from the original manufacturer or authorized distributors?
All SMAJ4746CE3/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 SMAJ4746CE3/TR13 meets industry standards.
7.What is the process for return or replacement of SMAJ4746CE3/TR13?
All SMAJ4746CE3/TR13 units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ4746CE3/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 SMAJ4746CE3/TR13 part is unused and in its original packaging.
Return procedure for SMAJ4746CE3/TR13:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ4746CE3/TR13 Tags
-
MMBZ5240B-7-F
Diodes Incorporated
-
BZT52C5V6T-7
Diodes Incorporated
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MMSZ5231B-7-F
Diodes Incorporated
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BZT52C15-7-F
Diodes Incorporated
-
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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