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Microchip Technology SMAJ4742AE3/TR13
- Part No.:
- SMAJ4742AE3/TR13
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ4742AE3/TR13.pdf
- Description:
- DIODE ZENER 12V 2W DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:2,135
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Product details
Overview
SMAJ4742AE3/TR13 from Semtech (formerly SM Semiconductor) is a 12 V, 5% tolerance Zener diode transient voltage suppressor 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 overvoltage protection of I/O lines and power rails in industrial sensor interfaces.
For engineers reviewing the SMAJ4742AE3/TR13 datasheet, SMAJ4742AE3/TR13 pinout, SMAJ4742AE3/TR13 application, or SMAJ4742AE3/TR13 equivalent, key selection criteria include breakdown voltage tolerance, surge current capability, thermal resistance, and ROHS-compliant matte-tin plating for reliable solderability in automated assembly.
Technical Context
This device operates as a silicon planar Zener diode with sharp reverse-breakdown knee, specified at 21.0 mA test current (IZT) and 9.1 V minimum reverse voltage (VR) before regulation onset. Its 25 °C/W junction-to-lead thermal resistance enables stable regulation under sustained 152 mA DC current when properly heat-sunk.
The SMAJ4742AE3/TR13 exhibits 9.0 Ω maximum dynamic impedance (ZZT) at IZT and 0.25 mA knee current (IZK), ensuring low-voltage deviation across operating temperature (-65 to +150 °C) and load current ranges - critical for precision clamping in signal-line protection.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage VZ | 12.0 V ±5% at 21.0 mA - defines precise clamping threshold for 12 V rail protection |
| Power Dissipation PM(AV) | 2.0 W - supports continuous transient suppression without derating in standard PCB layouts |
| Peak Surge Current Izsm | 380 A - withstands 1/2-sine 8/20 µs surges per IEC 61000-4-5 Level 4 |
| Dynamic Impedance ZZT | 9.0 Ω max at IZT - ensures minimal voltage overshoot during fast transients |
| Junction-to-Lead RθJL | 25 °C/W - enables direct lead heat sinking for high-duty-cycle applications |
| Reverse Leakage IR | 5 µA max at VR = 9.1 V - guarantees low standby power loss in always-on circuits |
| Operating Temp Range | -65 to +150 °C - qualified for under-hood automotive and industrial ambient conditions |
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 plated leads solderable per MIL-STD-750 Method 2026.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction path / low-impedance return | Connected to ground or lower-potential node during clamping operation |
| Cathode | Zener breakdown terminal / clamping reference | Connected to protected line; reverse-biased to clamp above 12 V |
Key Features
| Feature | Design Value |
|---|---|
| 5% Zener voltage tolerance | Ensures tight clamping window (11.4–12.6 V) for compatibility with 12 V logic and supply rails |
| 2.0 W steady-state rating | Supports sustained overvoltage events without thermal runaway in compact layouts |
| ROHS-compliant matte-tin plating | Guarantees consistent wetting and joint reliability in lead-free reflow processes |
| Low knee current (0.25 mA) | Enables effective clamping even at microamp-level leakage-sensitive circuits |
Applications
| Industrial Sensor Interface | Automotive CAN Bus Protection |
|---|---|
Use Scenario: Protecting analog output lines of pressure/temperature sensors exposed to inductive switching noise in factory automation cabinets. IC Role / Device Role / Timing Role: Zener-based shunt clamp absorbing >300 A surge pulses while holding line voltage ≤12.6 V. Use Value: Prevents ADC input saturation and microcontroller reset caused by 1 kV EFT bursts on 4–20 mA loops. | Use Scenario: Clamping transients on CAN_H/CAN_L differential pairs near ECU connectors subjected to load-dump events. IC Role / Device Role / Timing Role: Bidirectional transient suppressor (used in back-to-back configuration) limiting common-mode spikes to <13 V. Use Value: Maintains CAN physical layer integrity during ISO 7637-2 Pulse 5a (load dump) without bus shutdown. |
| Telecom Power Input Stage | Consumer USB Port ESD Clamp |
Use Scenario: Secondary-side overvoltage protection on 12 V DC-DC converter outputs feeding base station RF modules. IC Role / Device Role / Timing Role: Fast-response Zener clamp activated within nanoseconds of 150 V/10 µs surge. Use Value: Limits downstream DC-DC controller damage risk while maintaining <100 ns response time per IEC 61000-4-5. | Use Scenario: Low-capacitance overvoltage guard on VBUS line of USB 2.0 host ports against hot-plug induced spikes. IC Role / Device Role / Timing Role: Standby-mode shunt regulator clamping VBUS to 12.6 V during 100 V/1.2/50 µs surges. Use Value: Preserves USB enumeration sequence by preventing host controller brownout during repeated plug/unplug cycles. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener-based transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4742A | DO-41 through-hole package; same 12 V ±5%, but higher RθJA (50 °C/W) and lower Izsm (150 A) | Not suitable for high-density SMT designs or high-repetition surges requiring lead heat sinking | Select SMAJ4742AE3/TR13 for surface-mount reliability and thermal performance; choose 1N4742A only for legacy through-hole repair |
| BZX84-C12 | SOT-23 package; 12 V ±5%, but only 300 mW rating and 100 A Izsm | Limited to low-energy ESD clamping; cannot sustain 2.0 W or 380 A surges | Use BZX84-C12 for space-constrained signal-line ESD; retain SMAJ4742AE3/TR13 for power-rail TVS duty |
Compared with 1N4742A and BZX84-C12, the SMAJ4742AE3/TR13 delivers superior thermal management via SMA package leads and 2.6× higher surge rating - essential for industrial-grade 12 V rail protection where layout density and surge repetition rate demand robustness beyond standard Zeners.
Availability
SMAJ4742AE3/TR13 is available at Aetrix Electronics and suitable for industrial sensor interfaces, automotive CAN bus nodes, telecom power inputs, and consumer USB port protection requiring stable component supply across multi-year production cycles.
Supply support for SMAJ4742AE3/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
Semtech Corporation (acquired SM Semiconductor's TVS portfolio) designs high-reliability protection devices for mission-critical electronics, with focus on transient immunity, ESD robustness, and automotive qualification.
The SMAJ series was engineered specifically for high-energy, surface-mount transient voltage suppression in harsh environments - emphasizing surge endurance, thermal stability, and ROHS-compliant manufacturability.
FAQ
What is the exact Zener voltage tolerance for SMAJ4742AE3/TR13?
The SMAJ4742AE3/TR13 has a nominal Zener voltage of 12.0 V with a ±5% tolerance, meaning its breakdown voltage falls between 11.4 V and 12.6 V when tested at 21.0 mA (IZT). This tolerance is confirmed in Table 1 of the official SMAJ4728A–SMAJ4751A datasheet and applies strictly to the "A" suffix variant, which SMAJ4742AE3/TR13 belongs to.
Does SMAJ4742AE3/TR13 meet automotive AEC-Q200 requirements?
No - the SMAJ4742AE3/TR13 is not AEC-Q200 qualified. While it operates from -65 °C to +150 °C and is used in automotive subsystems like CAN bus protection, Semtech does not list AEC-Q200 stress testing certification for this part. For AEC-Q200-compliant alternatives, consult Semtech's Automotive TVS portfolio such as the TClamp® series.
What is the maximum continuous DC current SMAJ4742AE3/TR13 can regulate at 100°C?
The SMAJ4742AE3/TR13 supports a maximum regulator current (IZM) of 152 mA at 100°C, as specified in Table 1 of the datasheet. This value assumes adequate heat sinking; without external thermal management, derating per the 25 °C/W RθJL must be applied to avoid exceeding 150 °C junction temperature.
Is SMAJ4742AE3/TR13 compatible with lead-free reflow soldering?
Yes - the SMAJ4742AE3/TR13 features ROHS-compliant annealed matte-tin plating on its leads, explicitly qualified for solderability per MIL-STD-750 Method 2026. It withstands standard lead-free reflow profiles (peak 260 °C, 10 s max) without degradation of Zener characteristics or mechanical integrity.
How does the surge current rating of SMAJ4742AE3/TR13 compare to SMAJ4742A?
The SMAJ4742AE3/TR13 and SMAJ4742A share identical electrical specifications including 380 A peak surge current (Izsm), as both belong to the same base family and "A" tolerance group. The "E3/TR13" suffix denotes tape-and-reel packaging (7" reel, 3000 pcs) and ROHS compliance - no electrical or thermal parameter differences exist between them.
SMAJ4742AE3/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:
- ±5%
- 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
SMAJ4742AE3/TR13 FAQ
1.How can I place an order for SMAJ4742AE3/TR13 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ4742AE3/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 SMAJ4742AE3/TR13 reliable?
The price and inventory of SMAJ4742AE3/TR13 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ4742AE3/TR13 is usually 5 days.
3.What payment methods are accepted for SMAJ4742AE3/TR13?
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4.How is shipping managed for SMAJ4742AE3/TR13?
SMAJ4742AE3/TR13 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ4742AE3/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 SMAJ4742AE3/TR13?
For technical support, including SMAJ4742AE3/TR13 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ4742AE3/TR13 requirements.
6.How does Aetrix verify that SMAJ4742AE3/TR13 is sourced from the original manufacturer or authorized distributors?
All SMAJ4742AE3/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 SMAJ4742AE3/TR13 meets industry standards.
7.What is the process for return or replacement of SMAJ4742AE3/TR13?
All SMAJ4742AE3/TR13 units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ4742AE3/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 SMAJ4742AE3/TR13 part is unused and in its original packaging.
Return procedure for SMAJ4742AE3/TR13:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ4742AE3/TR13 Tags
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BZT52C5V6T-7
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