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Vishay General Semiconductor - Diodes Division SML4749-E3/5A
- Part No.:
- SML4749-E3/5A
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- Single Zener Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SML4749-E3/5A.pdf
- Description:
- DIODE ZENER 24V 1W DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:7,500
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Product details
Overview
SML4749-E3/5A from Vishay Semiconductors is a surface-mount Zener diode with a nominal zener voltage of 24 V, ±5 % tolerance (suffix A), 1000 mW power dissipation at TL = 75 °C, and DO-214AC (SMA) package. It delivers low dynamic impedance (18.2 Ω at IZT = 10.5 mA), low regulation factor, and AEC-Q101 qualification for automotive-grade reliability in voltage reference and overvoltage protection circuits.
For engineers reviewing the SML4749-E3/5A datasheet, SML4749-E3/5A pinout, SML4749-E3/5A application, or SML4749-E3/5A equivalent, key selection criteria include zener voltage accuracy, surge current rating (190 mApk), thermal performance up to 150 °C junction temperature, RoHS-compliant construction, and MSL level 1 moisture sensitivity for standard reflow compatibility.
Technical Context
The SML4749-E3/5A operates as a precision voltage reference device using silicon PN-junction Zener breakdown at 24 V nominal. Its single-die construction in DO-214AC enables stable regulation under pulse and DC conditions, with reverse current limited to 0.25 μA at VR = 18.2 V and dynamic impedance measured at 10.5 mA test current.
Designed for surface-mounted systems requiring high-temperature soldering (260 °C/10 s), it maintains regulation across -65 °C to +150 °C storage range and supports surge current per JEDEC® 8.3 ms square-wave method. The UL 94 V-0 molding compound ensures flame resistance in compact PCB layouts.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 24 V nominal, ±5 % tolerance - ensures tight voltage reference stability for feedback loops and clamping. |
| Power Dissipation (Ptot) | 1000 mW at TL = 75 °C - supports sustained operation in thermally constrained SMT designs. |
| Zener Test Current (IZT) | 10.5 mA - defines operating point where VZ and dynamic impedance are specified and optimized. |
| Dynamic Impedance (ZZ) | 18.2 Ω at IZT - minimizes output voltage variation under load transients in regulation circuits. |
| Surge Current (IRM) | 190 mApk (8.3 ms pulse) - provides transient overvoltage resilience without degradation. |
| Junction Temperature (Tj) | 150 °C maximum - enables deployment in under-hood automotive and industrial environments. |
| Moisture Sensitivity Level | MSL level 1 - allows unlimited floor life and standard reflow without baking preconditioning. |
Pinout & Package
DO-214AC (SMA) surface-mount package: molded plastic case with cathode band marking; dimensions 4.93 mm × 5.28 mm × 2.29 mm (L × W × H); weight 64 mg; UL 94 V-0 flammability rating.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / reference ground node | Connected to circuit ground or lower-potential rail during Zener operation; carries forward current when biased below VZ. |
| Cathode | Zener breakdown terminal / regulated output node | Provides stable 24 V reference when reverse-biased; marked by band; connects to input or supply rail needing regulation/clamping. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive applications including engine control units and body electronics requiring extended temperature and reliability compliance. |
| Low Zener impedance (18.2 Ω) | Reduces output voltage deviation under varying load currents, improving accuracy in precision reference designs. |
| High-temperature soldering guarantee | Rated for 260 °C/10 s at terminals - compatible with lead-free reflow profiles without parametric shift or delamination. |
| ±5 % voltage tolerance (suffix A) | Enables tighter feedback loop control versus standard ±10 % parts, reducing need for external trimming in power supply designs. |
| UL 94 V-0 flammability rating | Meets stringent safety requirements for consumer, industrial, and automotive end equipment with fire-risk constraints. |
Applications
| Automotive Engine Control Unit (ECU) Reference | Industrial PLC Analog Input Protection |
|---|---|
Use Scenario: Stabilizing 24 V reference for microcontroller ADC bias and sensor excitation in under-hood ECU modules. IC Role / Device Role / Timing Role: Zener voltage reference and overvoltage clamp for analog front-end circuitry. Use Value: Maintains 24 V ±1.2 V accuracy across -40 °C to +125 °C ambient, supporting AEC-Q100 Grade 1 compliance. |
Use Scenario: Protecting 24 V-powered analog input channels in programmable logic controllers against field-wiring surges. IC Role / Device Role / Timing Role: Reverse-biased shunt clamp limiting input voltage to safe levels during transients. Use Value: Absorbs 190 mApk surge energy without failure, preserving downstream op-amp and ADC integrity. |
| Telecom Power Supply Feedback Loop | Medical Diagnostic Equipment Bias Supply |
Use Scenario: Providing precise 24 V reference for optocoupler-based feedback in isolated DC-DC converters. IC Role / Device Role / Timing Role: Primary voltage sensing element in secondary-side regulation circuitry. Use Value: Low 18.2 Ω dynamic impedance minimizes loop gain variation, improving transient response and output regulation. |
Use Scenario: Generating stable bias voltage for photodiode amplifiers and signal-conditioning stages in portable diagnostic tools. IC Role / Device Role / Timing Role: Low-noise, low-drift voltage reference source for sensitive analog signal paths. Use Value: ±5 % tolerance and 150 °C max junction temperature support long-term calibration stability in battery-powered devices. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX84-C24LT1G | 24 V ±5 %, 300 mW Ptot, SOT-23 package, higher ZZ (50 Ω), lower IRM (100 mApk) | Limited to low-power portable electronics; unsuitable for 1 W thermal loads or automotive under-hood use | Select only for space-constrained, low-current biasing where DO-214AC footprint is unavailable |
| 1N4749A | 24 V ±5 %, 1000 mW Ptot, DO-41 through-hole package, same electrical specs but no AEC-Q101 qualification | Requires wave soldering or hand assembly; not qualified for automotive vibration or thermal cycling stress | Prefer for legacy through-hole designs or non-automotive industrial applications where surface-mount is not required |
Compared with BZX84-C24LT1G and 1N4749A, the SML4749-E3/5A uniquely combines AEC-Q101 qualification, DO-214AC SMT compatibility, and full 1000 mW power handling-making it the only choice for new automotive and high-reliability industrial designs demanding both surface-mount integration and automotive-grade validation.
Availability
SML4749-E3/5A is available at Aetrix Electronics and suitable for automotive engine control units, industrial PLC analog input protection, telecom power supply feedback loops, and medical diagnostic equipment bias supplies requiring stable component supply and long-term lifecycle assurance.
Supply support for SML4749-E3/5A 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
Vishay Intertechnology is a global semiconductor manufacturer specializing in discrete components, sensors, and passive elements, with emphasis on reliability, precision, and application-specific performance.
The SML47xx series is part of Vishay's surface-mount Zener diode product line engineered for high-stability voltage reference and transient suppression in automotive, industrial, and communications systems where AEC-Q101 compliance and robust thermal performance are mandatory.
FAQ
What is the zener voltage tolerance for SML4749-E3/5A?
The SML4749-E3/5A has a zener voltage tolerance of ±5 %, indicated by the "A" suffix in the ordering code. This means its nominal 24 V zener voltage is guaranteed between 22.8 V and 25.2 V at IZT = 10.5 mA and Tamb = 25 °C, enabling tighter regulation than standard ±10 % Zeners in critical feedback paths.
Is SML4749-E3/5A qualified for automotive applications?
Yes, the SML4749-E3/5A is AEC-Q101 qualified, as confirmed in Vishay's official datasheet revision 1.9. This qualification covers stress testing for temperature cycling, humidity bias, mechanical shock, and high-temperature operating life-making SML4749-E3/5A suitable for under-hood and chassis-mounted automotive electronics.
What is the maximum surge current rating for SML4749-E3/5A?
The SML4749-E3/5A supports a peak surge current (IRM) of 190 mApk under JEDEC®-defined 8.3 ms pulse conditions. This value is measured at 25 °C ambient and reflects the device's ability to absorb transient energy without parametric shift or failure-critical for input-stage overvoltage protection.
Does SML4749-E3/5A require moisture preconditioning before reflow?
No, the SML4749-E3/5A is rated MSL level 1 per J-STD-020, meaning it has unlimited floor life and may be placed directly into standard lead-free reflow ovens without baking. Its DO-214AC package uses moisture-resistant molding compound compliant with UL 94 V-0.
What is the dynamic impedance of SML4749-E3/5A and why does it matter?
The SML4749-E3/5A exhibits a dynamic impedance (ZZ) of 18.2 Ω at IZT = 10.5 mA. This low value indicates minimal change in zener voltage under varying load current, which directly improves regulation accuracy in voltage reference and error amplifier feedback circuits-especially during fast load transients.
SML4749-E3/5A Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Series:
- -
- Package/Case:
- DO-214AC, SMA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 24 V
- Tolerance:
- ±10%
- Power - Max:
- 1 W
- Impedance (Max) (Zzt):
- 25 Ohms
- Current - Reverse Leakage @ Vr:
- 5 µA @ 18.2 V
- Voltage - Forward (Vf) (Max) @ If:
- -
- Operating Temperature:
- 150°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMA)
SML4749-E3/5A FAQ
1.How can I place an order for SML4749-E3/5A through Aetrix?
Please submit a Request for Quotation (RFQ) for SML4749-E3/5A 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 SML4749-E3/5A reliable?
The price and inventory of SML4749-E3/5A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SML4749-E3/5A is usually 5 days.
3.What payment methods are accepted for SML4749-E3/5A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SML4749-E3/5A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SML4749-E3/5A?
SML4749-E3/5A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SML4749-E3/5A 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 SML4749-E3/5A?
For technical support, including SML4749-E3/5A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SML4749-E3/5A requirements.
6.How does Aetrix verify that SML4749-E3/5A is sourced from the original manufacturer or authorized distributors?
All SML4749-E3/5A 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 SML4749-E3/5A meets industry standards.
7.What is the process for return or replacement of SML4749-E3/5A?
All SML4749-E3/5A units undergo pre-shipment inspection (PSI). If there is an issue with SML4749-E3/5A, 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 SML4749-E3/5A part is unused and in its original packaging.
Return procedure for SML4749-E3/5A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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