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Microchip Technology SMAJ4749CE3/TR13
- Part No.:
- SMAJ4749CE3/TR13
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ4749CE3/TR13.pdf
- Description:
- DIODE ZENER 24V 2W DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:7,219
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Product details
Overview
SMAJ4749CE3/TR13 from SM Semiconductors is a 24.0 V, ±2% tolerance Zener diode in SMA (DO-214AC) package, rated for 2.0 W steady-state power dissipation, 10.5 mA test current, and 25.0 Ω maximum dynamic impedance at IZT, used for precision voltage regulation and transient overvoltage protection in low-profile power rails.
For engineers reviewing the SMAJ4749CE3/TR13 datasheet, SMAJ4749CE3/TR13 pinout, SMAJ4749CE3/TR13 application, or SMAJ4749CE3/TR13 equivalent, key selection factors include its 24.0 V nominal breakdown voltage, ±2% tolerance (C suffix), 25 °C/ W thermal resistance, 18.2 V minimum clamping voltage at IZSM, and ROHS-compliant matte-tin plating for reliable solderability.
Technical Context
This device operates as a silicon Zener diode with sharp reverse-breakdown knee characteristics, specified for regulation across a broad current range (IZK = 0.25 mA to IZM = 76 mA) and temperature span (–65 °C to +150 °C). Its 2.0 W power rating and 25 °C/W junction-to-lead thermal resistance enable stable operation under sustained DC bias when mounted on thermally adequate PCB copper.
The SMAJ4749CE3/TR13 exhibits 25.0 Ω dynamic impedance at 10.5 mA test current and 750 Ω maximum knee impedance at 0.25 mA, ensuring low-voltage drift during small-signal regulation. Reverse leakage is limited to ≤5 µA at 18.2 V (VR), supporting low-power standby circuit integrity.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage VZ | 24.0 V ±2% at 10.5 mA - precise reference for 24 V rail stabilization |
| Power Dissipation PM(AV) | 2.0 W - supports continuous regulation without forced cooling on standard FR4 |
| Dynamic Impedance ZZT | 25.0 Ω max at IZT = 10.5 mA - low output impedance for minimal load-induced voltage shift |
| Thermal Resistance RθJL | 25 °C/W - enables predictable junction temperature rise with lead-mounted heat sinking |
| Reverse Leakage IR | ≤5 µA at VR = 18.2 V - preserves low-power sleep mode integrity |
| Clamping Voltage VC | ≤38.9 V at IPP = 190 A (8/20 µs) - suppresses transients above 24 V without damaging downstream ICs |
| Operating Temperature | –65 °C to +150 °C - qualified for automotive under-hood and industrial control environments |
Pinout & Package
Package: SMA (DO-214AC), surface-mount, void-free thermosetting epoxy case, cathode indicated by band, weight ≈0.3 g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / low-side connection | Connected to ground or lower-potential node during reverse-biased regulation |
| Cathode | Zener breakdown terminal / high-side connection | Connected to protected line; conducts when voltage exceeds 24.0 V, shunting surge current to ground |
Key Features
| Feature | Design Value |
|---|---|
| ±2% Zener voltage tolerance (C suffix) | Enables tighter regulation margins than 5% or 10% variants, reducing need for post-regulation trimming |
| 2.0 W steady-state power rating | Supports sustained DC regulation in space-constrained designs without heatsink dependency |
| ROHS-compliant matte-tin plating | Ensures repeatable solder joint formation per MIL-STD-750 Method 2026, compatible with lead-free reflow |
| Low 25 °C/W junction-to-lead thermal resistance | Permits direct PCB copper pour attachment for thermal management without thermal vias |
| Sharp breakdown knee (IZK = 0.25 mA) | Provides stable regulation onset at microamp-level currents, critical for battery-backed circuits |
Applications
| Automotive Power Rail Protection | Industrial Sensor Signal Conditioning |
|---|---|
Use Scenario: Protecting 24 V CAN bus power lines from load-dump transients and alternator ripple. IC Role / Device Role / Timing Role: Zener clamp placed between VCC and GND to limit voltage excursions to ≤38.9 V during 190 A surges. Use Value: Prevents latch-up or permanent damage to CAN transceivers and microcontrollers operating at 24 V nominal. | Use Scenario: Stabilizing reference voltage for 4–20 mA transmitter front-end op-amps in PLC analog input modules. IC Role / Device Role / Timing Role: Precision 24.0 V ±2% shunt regulator providing low-drift bias for current-loop drivers. Use Value: Maintains <±0.5% output current accuracy over –40 °C to +85 °C ambient due to tight VZ tolerance and low ZZT. |
| Telecom DC-DC Converter Feedback | Consumer Appliance Motor Drive Gate Bias |
Use Scenario: Providing stable feedback reference for isolated 24 V flyback converters in VoIP power supplies. IC Role / Device Role / Timing Role: Secondary-side shunt regulator replacing TL431 where ultra-low quiescent current (<5 µA at 18.2 V) is required. Use Value: Reduces no-load power loss by >30% compared to standard 2.5 V references, improving Energy Star compliance. | Use Scenario: Clamping gate-source voltage of N-channel MOSFETs in 24 V BLDC motor half-bridges. IC Role / Device Role / Timing Role: Transient voltage suppressor connected between gate and source to prevent VGS overstress during Miller-induced spikes. Use Value: Limits VGS to ≤24 V ±2%, ensuring reliable turn-off and preventing parasitic turn-on during fast switching. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX84-C24LT1G | 24 V ±5%, SOT-23 package, 300 mW PD, 200 Ω ZZT | Lower power handling and higher impedance limit use to signal-level or low-current biasing only | Select when board space is constrained and surge current <5 A; not suitable for 2.0 W continuous regulation |
| 1N4749A | 24 V ±5%, DO-41 package, 1.0 W PM(AV), 25 °C/W RθJA (not RθJL) | Through-hole mounting, higher thermal resistance, derated power in compact layouts | Select for legacy through-hole designs or where manual rework accessibility is prioritized over thermal performance |
Compared with BZX84-C24LT1G and 1N4749A, SMAJ4749CE3/TR13 delivers superior thermal performance (25 °C/W vs. >100 °C/W), higher surge capability (190 A vs. <10 A), and tighter voltage tolerance-making it optimal for 24 V industrial power rail protection where reliability under sustained stress is critical.
Availability
SMAJ4749CE3/TR13 is available at Aetrix Electronics and suitable for automotive power rail protection, industrial sensor signal conditioning, and telecom DC-DC converter feedback requiring stable component supply with guaranteed long-term continuity.
Supply support for SMAJ4749CE3/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 bridge rectifiers for industrial and automotive markets.
The SMAJ47xxA series was designed specifically for high-reliability, surface-mount voltage regulation and transient suppression in space-constrained 24 V systems where thermal efficiency and tight tolerance are mandatory.
FAQ
What is the Zener voltage tolerance of SMAJ4749CE3/TR13?
The SMAJ4749CE3/TR13 has a ±2% Zener voltage tolerance, indicated by the 'C' suffix in its part number. This means its breakdown voltage is guaranteed between 23.52 V and 24.48 V at 10.5 mA test current and 25 °C ambient. This tighter tolerance supports precision regulation tasks where 5% or 10% variants would require additional calibration or margining.
Does SMAJ4749CE3/TR13 meet ROHS requirements?
Yes, SMAJ4749CE3/TR13 features ROHS-compliant annealed matte-tin plating on its terminals, verified per MIL-STD-750 Method 2026 for solderability. The void-free thermosetting epoxy case meets UL94V-0 flammability standards, and the entire construction complies with Directive 2011/65/EU without exemptions.
What is the maximum surge current rating for SMAJ4749CE3/TR13?
The SMAJ4749CE3/TR13 is rated for a peak surge current (IZSM) of 190 A under an 8/20 µs waveform, corresponding to its 24.0 V breakdown voltage. This value is derived from the device's ability to clamp transient energy while maintaining junction temperature below 150 °C, as validated in the manufacturer's transient testing protocol.
Can SMAJ4749CE3/TR13 be used as a replacement for SMAJ4749A?
No-SMAJ4749CE3/TR13 is not a drop-in replacement for SMAJ4749A. While both share the same 24.0 V nominal voltage and SMA package, SMAJ4749A has ±5% tolerance and no ROHS designation. SMAJ4749CE3/TR13 adds ±2% tolerance, ROHS compliance, and tape-and-reel packaging (TR13), requiring validation of layout thermal relief and procurement documentation alignment.
What is the clamping voltage of SMAJ4749CE3/TR13 at rated surge current?
At its rated peak surge current of 190 A (8/20 µs waveform), SMAJ4749CE3/TR13 clamps to a maximum voltage of 38.9 V. This value is measured per industry-standard transient testing and ensures downstream 24 V-rated ICs remain within absolute maximum ratings during severe inductive switching events.
SMAJ4749CE3/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):
- 24 V
- Tolerance:
- ±2%
- Power - Max:
- 2 W
- Impedance (Max) (Zzt):
- 25 Ohms
- Current - Reverse Leakage @ Vr:
- 5 µA @ 18.2 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
SMAJ4749CE3/TR13 FAQ
1.How can I place an order for SMAJ4749CE3/TR13 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ4749CE3/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 SMAJ4749CE3/TR13 reliable?
The price and inventory of SMAJ4749CE3/TR13 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ4749CE3/TR13 is usually 5 days.
3.What payment methods are accepted for SMAJ4749CE3/TR13?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ4749CE3/TR13 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ4749CE3/TR13?
SMAJ4749CE3/TR13 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ4749CE3/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 SMAJ4749CE3/TR13?
For technical support, including SMAJ4749CE3/TR13 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ4749CE3/TR13 requirements.
6.How does Aetrix verify that SMAJ4749CE3/TR13 is sourced from the original manufacturer or authorized distributors?
All SMAJ4749CE3/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 SMAJ4749CE3/TR13 meets industry standards.
7.What is the process for return or replacement of SMAJ4749CE3/TR13?
All SMAJ4749CE3/TR13 units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ4749CE3/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 SMAJ4749CE3/TR13 part is unused and in its original packaging.
Return procedure for SMAJ4749CE3/TR13:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ4749CE3/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
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BZX84C3V3LT1G
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MM5Z5V1ST1G
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