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Vishay General Semiconductor - Diodes Division SML4749AHE3_A/I
- Part No.:
- SML4749AHE3_A/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- Single Zener Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SML4749AHE3_A/I.pdf
- Description:
- DIODE ZENER 24V 1W DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:3,616
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Product details
Overview
SML4749AHE3_A/I from Vishay Semiconductors is a surface-mount Zener diode with nominal zener voltage of 24 V, ±5 % tolerance (suffix A), 10.5 mA test current (IZT), and 25 Ω dynamic impedance at IZT - designed for precision voltage regulation in power supply feedback loops, overvoltage protection circuits, and reference voltage generation in industrial DC-DC converters.
For engineers reviewing the SML4749AHE3_A/I datasheet, SML4749AHE3_A/I pinout, SML4749AHE3_A/I application, or SML4749AHE3_A/I equivalent, this device delivers stable 24 V clamping under 1000 mW power dissipation at TL = 75 °C, supports AEC-Q101 qualification (HE3_X suffix), and operates across -65 °C to +150 °C junction temperature range - critical for automotive body control modules and industrial sensor signal conditioning.
Technical Context
This Zener diode functions as a two-terminal voltage reference element, operating in reverse breakdown mode with low regulation factor and low zener impedance (25 Ω at 10.5 mA). Its SMA (DO-214AC) package enables high-density PCB layout while maintaining 260 °C/10 s soldering robustness and MSL level 1 moisture sensitivity rating.
The device exhibits a typical temperature coefficient of +8.5 mV/°C near 24 V (per Fig. 3), and supports non-repetitive surge current up to 750 mApk (8.3 ms pulse), making it suitable for transient suppression in 24 V rail monitoring applications where thermal stability and pulse survivability are essential.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 24 V nominal, ±5 % tolerance - ensures tight regulation for 24 V system references requiring < ±1.2 V deviation. |
| Test Current (IZT) | 10.5 mA - defines the operating point where VZ and dynamic impedance are specified; matches common feedback divider bias currents. |
| Dynamic Impedance (ZZ) | 25 Ω at IZT - low impedance maintains stable output voltage under varying load conditions in regulation circuits. |
| Power Dissipation (Ptot) | 1000 mW at TL = 75 °C - enables use in compact power supplies without forced cooling when mounted on adequate copper area. |
| Junction Temperature (Tj) | 150 °C maximum - supports operation in under-hood automotive environments and sealed industrial enclosures. |
| Surge Current (IRM) | 750 mApk (8.3 ms) - withstands short-duration transients per JEDEC method, protecting downstream circuitry from line spikes. |
Pinout & Package
Package: SMA (DO-214AC), surface-mount plastic case with cathode band marking; dimensions 4.93 mm × 3.99 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 in shunt regulator | Connected to system ground or lower-potential rail; forms return path during reverse breakdown. |
| Cathode | Zener voltage reference terminal / Input node in shunt regulator | Connected to regulated voltage node; clamps voltage to 24 V when reverse-biased above breakdown threshold. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive applications including body electronics and powertrain subsystems requiring reliability under thermal cycling and vibration. |
| ±5 % voltage tolerance | Enables tighter closed-loop regulation than standard ±10 % parts, reducing need for post-production trimming in voltage reference designs. |
| Low dynamic impedance (25 Ω) | Minimizes output voltage variation under load changes - critical for stable feedback in isolated flyback controllers. |
| MSL Level 1 rating | Allows unlimited floor life before reflow; eliminates bake requirements and simplifies SMT manufacturing flow. |
| 260 °C/10 s soldering guarantee | Ensures mechanical and electrical integrity after standard lead-free reflow profiles without degradation. |
Applications
| Automotive Body Control Module | Industrial DC-DC Converter Feedback |
|---|---|
Use Scenario: Regulating 24 V battery-supplied microcontroller supply rails in door module ECUs subject to load dump transients. IC Role / Device Role / Timing Role: Shunt voltage reference and overvoltage clamp protecting LDO input stage. Use Value: Maintains 24 V ±1.2 V regulation during 12–24 V system transitions and absorbs 750 mApk surges without failure. |
Use Scenario: Providing precise 24 V reference for optocoupler-based feedback in 48 V-to-24 V isolated buck-boost converters. IC Role / Device Role / Timing Role: Zener reference node in secondary-side error amplifier circuit. Use Value: 25 Ω dynamic impedance ensures < 25 mV output variation across 5–15 mA feedback current range. |
| Programmable Logic Controller I/O Protection | Medical Power Supply Monitoring |
Use Scenario: Clamping 24 V digital input channels against ESD and inductive kickback in PLC backplanes. IC Role / Device Role / Timing Role: Transient voltage suppressor at field-side interface connector. Use Value: Responds within nanoseconds to >24 V excursions and sustains repeated 750 mApk pulses per JEDEC test method. |
Use Scenario: Monitoring 24 V auxiliary rail in Class II medical AC/DC power supplies for fault detection. IC Role / Device Role / Timing Role: Precision voltage sense element feeding comparator input. Use Value: ±5 % tolerance and +8.5 mV/°C tempco enable accurate trip-point setting across -20 °C to +70 °C ambient. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX84-C24LT1G | 24 V ±5 %, SOT-23 package, 350 mW Ptot, 40 Ω ZZ at 5 mA - lower power rating and higher impedance. | Best suited for low-current bias networks; not recommended for >10 mA regulation or surge-prone environments. | Select when board space is constrained and power dissipation remains below 350 mW. |
| 1N4749A | 24 V ±5 %, DO-41 through-hole package, 1000 mW Ptot, 25 Ω ZZ at 10.5 mA - identical electrical specs but incompatible mounting. | Requires through-hole assembly; unsuitable for fully SMT production or high-density layouts. | Choose only for legacy repair, prototyping with breadboards, or mixed-technology boards where reflow compatibility is not required. |
Compared with BZX84-C24LT1G and 1N4749A, the SML4749AHE3_A/I uniquely combines AEC-Q101 qualification, SMA surface-mount compatibility, and full 1000 mW thermal capability - making it the preferred choice for new automotive and industrial SMT designs demanding reliability, density, and power handling.
Availability
SML4749AHE3_A/I is available at Aetrix Electronics and suitable for automotive body control modules, industrial DC-DC converter feedback networks, and programmable logic controller I/O protection circuits requiring stable component supply, long-term lifecycle support, and traceable RoHS-compliant sourcing.
Supply support for SML4749AHE3_A/I 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 automotive-grade qualification.
The SML47xxA series belongs to Vishay's surface-mount Zener diode product line, engineered specifically for high-stability voltage reference and overvoltage protection in automotive, industrial, and medical power systems where AEC-Q101 compliance and thermal robustness are mandatory.
FAQ
What is the zener voltage tolerance of SML4749AHE3_A/I?
The SML4749AHE3_A/I has a zener voltage tolerance of ±5 %, as indicated by the "A" suffix in its part number. This means its nominal 24 V zener voltage is guaranteed between 22.8 V and 25.2 V at 10.5 mA test current and 25 °C ambient - enabling tighter regulation than standard ±10 % Zeners in feedback and reference applications.
Is SML4749AHE3_A/I qualified for automotive use?
Yes, the SML4749AHE3_A/I is AEC-Q101 qualified, confirmed by the "HE3_X" ordering code format (where "X" denotes revision) and explicitly stated in Vishay's datasheet Rev. 2.2. This qualification covers stress tests including temperature cycling, humidity bias, and high-temperature operating life - validating its suitability for automotive body electronics and power distribution modules.
What package type does SML4749AHE3_A/I use?
The SML4749AHE3_A/I uses the SMA (DO-214AC) surface-mount package - measuring 4.93 mm × 3.99 mm × 2.29 mm with a cathode band marking. It is RoHS-compliant, rated MSL level 1, and qualified for 260 °C/10 s lead-free reflow, making it compatible with standard high-volume SMT assembly processes.
What is the maximum power dissipation of SML4749AHE3_A/I?
The SML4749AHE3_A/I has a maximum power dissipation of 1000 mW at terminal temperature (TL) of 75 °C. Derating begins linearly above 75 °C, reaching zero at 150 °C junction temperature. This rating assumes PCB mounting on 8 mm × 8 mm × 2 mm copper pads - critical for thermal design in compact power supplies.
Does SML4749AHE3_A/I have a specified surge current rating?
Yes, the SML4749AHE3_A/I is rated for a non-repetitive surge current (IRM) of 750 mApk under an 8.3 ms pulse width square wave condition per JEDEC method. This rating applies at 25 °C ambient and validates its ability to absorb transient energy in 24 V system protection circuits without parametric shift or failure.
SML4749AHE3_A/I 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:
- ±5%
- 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:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMA)
SML4749AHE3_A/I FAQ
1.How can I place an order for SML4749AHE3_A/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SML4749AHE3_A/I 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 SML4749AHE3_A/I reliable?
The price and inventory of SML4749AHE3_A/I are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SML4749AHE3_A/I is usually 5 days.
3.What payment methods are accepted for SML4749AHE3_A/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SML4749AHE3_A/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SML4749AHE3_A/I?
SML4749AHE3_A/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SML4749AHE3_A/I 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 SML4749AHE3_A/I?
For technical support, including SML4749AHE3_A/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SML4749AHE3_A/I requirements.
6.How does Aetrix verify that SML4749AHE3_A/I is sourced from the original manufacturer or authorized distributors?
All SML4749AHE3_A/I 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 SML4749AHE3_A/I meets industry standards.
7.What is the process for return or replacement of SML4749AHE3_A/I?
All SML4749AHE3_A/I units undergo pre-shipment inspection (PSI). If there is an issue with SML4749AHE3_A/I, 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 SML4749AHE3_A/I part is unused and in its original packaging.
Return procedure for SML4749AHE3_A/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SML4749AHE3_A/I Tags
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