My Inquiry
My Account
Microchip Technology SMAJ4749AE3/TR13
- Part No.:
- SMAJ4749AE3/TR13
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ4749AE3/TR13.pdf
- Description:
- DIODE ZENER 24V 2W DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:4,147
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMAJ4749AE3/TR13 from SM Semiconductor is a 24.0 V, 5% tolerance Zener diode transient voltage suppressor in SMA (DO-214AC) package, rated for 2.0 W steady-state power dissipation, 10.5 mA test current, and 25.0 Ω dynamic impedance at IZT, used for overvoltage protection on low-voltage signal lines in automotive sensor interfaces.
For engineers reviewing the SMAJ4749AE3/TR13 datasheet, SMAJ4749AE3/TR13 pinout, SMAJ4749AE3/TR13 application, or SMAJ4749AE3/TR13 equivalent, key selection criteria include breakdown voltage tolerance, surge current capability (190 A), thermal resistance (25 °C/W), and ROHS-compliant matte-tin plating for reliable solderability in high-reliability PCB assemblies.
Technical Context
This device operates as a silicon planar Zener diode optimized for transient suppression, with a sharp knee at 1.0 mA (IZK) and specified reverse leakage ≤5 µA at 18.2 V (VR). Its 25 °C/W junction-to-lead thermal resistance enables stable regulation under pulsed surge conditions when mounted to adequate copper area.
The SMAJ4749AE3/TR13 exhibits 25.0 Ω dynamic impedance at 10.5 mA test current and maintains regulation across -65 °C to +150 °C operating temperature range, supporting use in environments where thermal cycling and voltage transients co-occur-such as automotive body control modules and industrial I/O protection circuits.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage VZ | 24.0 V ±5% at 10.5 mA - defines clamping threshold for overvoltage events in 24 V rail protection |
| Power Dissipation PM(AV) | 2.0 W - maximum continuous DC power handling without heat sinking |
| Dynamic Impedance ZZT | 25.0 Ω at IZT = 10.5 mA - determines voltage rise under transient current, critical for precision clamping |
| Surge Current IZSM | 190 A - peak non-repetitive current capability for 1/2 sine wave, 1/120 s duration |
| Reverse Leakage IR | ≤5 µA at VR = 18.2 V - ensures minimal standby power loss in always-on sensor circuits |
| Thermal Resistance RθJL | 25 °C/W - enables predictable junction temperature rise with lead-mounted thermal path |
| Operating Temperature | -65 °C to +150 °C - supports deployment in under-hood automotive and industrial ambient extremes |
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 terminals.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current entry during forward bias / reference node during reverse clamp | Connected to protected circuit ground or lower-potential node; establishes reference for clamping action |
| Cathode | Current exit during forward bias / high-impedance node during reverse operation | Connected to protected line (e.g., CAN_H, LIN, sensor output); carries surge current to ground during overvoltage |
Key Features
| Feature | Design Value |
|---|---|
| 5% Zener voltage tolerance | Ensures tight clamping window (22.8–25.2 V) for compatibility with 24 V system fault thresholds |
| 25 °C/W junction-to-lead thermal resistance | Allows direct thermal coupling to PCB copper for sustained 2.0 W operation without external heatsink |
| ROHS-compliant matte-tin plating | Guarantees repeatable solder joint formation per MIL-STD-750 Method 2026, critical for automotive reflow profiles |
| 190 A peak surge rating | Withstands ISO 7637-2 Pulse 1/2/5a transients common in 24 V vehicle electrical systems |
| Cathode band polarity marking | Enables unambiguous orientation during automated placement and visual inspection on high-density PCBs |
Applications
| Automotive Sensor Protection | Industrial I/O Interface |
|---|---|
Use Scenario: Protecting analog output lines of pressure/temperature sensors in engine control units exposed to load dump and inductive switching noise. IC Role / Device Role / Timing Role: Zener-based shunt clamp that diverts transient energy to ground before it reaches downstream ADC input or op-amp stage. Use Value: Maintains signal integrity by limiting voltage excursion to ≤25.2 V during 190 A surges, preventing latch-up or damage to 3.3 V/5 V interface ICs. | Use Scenario: Safeguarding RS-485 transceiver data lines in programmable logic controllers subjected to EFT and surge per IEC 61000-4-4/5. IC Role / Device Role / Timing Role: Standoff protector placed between bus line and transceiver VCC/GND rails to absorb coupled transients before they propagate into IC substrate. Use Value: Enables compliance with industrial immunity standards using single-device solution with <5 µA leakage at 18.2 V, minimizing standby current impact. |
| Consumer Power Adapter Feedback | Telecom Line Card Surge Suppression |
Use Scenario: Stabilizing optocoupler feedback voltage in isolated 24 V AC/DC adapters where primary-side regulation depends on precise Zener reference. IC Role / Device Role / Timing Role: Precision voltage reference and overvoltage limiter in secondary-side feedback loop of flyback converters. Use Value: Delivers 24.0 V ±5% reference with 25 Ω dynamic impedance, ensuring stable regulation across 10.5–100 mA load range and 100 °C ambient. | Use Scenario: Front-end protection for Ethernet PHY power pins in telecom base station line cards exposed to lightning-induced surges on DC distribution buses. IC Role / Device Role / Timing Role: Primary-level shunt suppressor on 24 V or 48 V backplane rails, coordinated with downstream TVS arrays. Use Value: Handles 190 A single-event surge while maintaining <5 µA leakage at 18.2 V, preserving system efficiency during normal operation. |
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 |
|---|---|---|---|
| 1N5357BRLG | Same 24 V nominal, but 10% tolerance (vs. 5%), higher ZZT = 35 Ω, TO-220 package | Requires through-hole mounting and larger board area; less suitable for high-density SMT layouts | Select when legacy TO-220 footprint is fixed and tighter voltage tolerance is not required |
| SZ1SMA4749HE3/TR13 | Identical 24 V ±5%, same SMA package, but manufactured by Vishay; ZZT = 25 Ω, IZSM = 190 A confirmed | No functional or layout change needed; fully interchangeable in new designs and second-source programs | Preferred for dual-sourcing strategies requiring identical electrical and mechanical specifications |
Compared with SMAJ4749AE3/TR13, the 1N5357BRLG trades tighter voltage control for through-hole robustness, while SZ1SMA4749HE3/TR13 offers identical performance in a validated second-source configuration-enabling supply chain resilience without design revision.
Availability
SMAJ4749AE3/TR13 is available at Aetrix Electronics and suitable for automotive sensor protection, industrial I/O interface hardening, and telecom line card surge suppression requiring stable component supply across extended production lifecycles.
Supply support for SMAJ4749AE3/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 Semiconductor is a Taiwan-based manufacturer specializing in discrete semiconductors, including Zener diodes, TVS devices, and rectifiers, with emphasis on automotive-grade reliability and AEC-Q101 qualified products.
The SMAJ47xxA series is designed specifically for high-reliability transient suppression in 12 V and 24 V automotive and industrial systems, balancing tight voltage tolerance, surge robustness, and SMT manufacturability in the SMA package.
FAQ
What is the Zener voltage tolerance of SMAJ4749AE3/TR13?
The SMAJ4749AE3/TR13 has a nominal Zener voltage of 24.0 V with a ±5% tolerance, meaning its actual breakdown voltage falls within 22.8 V to 25.2 V at the specified 10.5 mA test current. This tighter tolerance compared to standard 10% Zener diodes ensures more predictable clamping behavior in safety-critical 24 V system protection circuits, and is explicitly defined in the SM Semiconductor datasheet for the SMAJ4749A variant.
Does SMAJ4749AE3/TR13 meet automotive qualification standards?
The SMAJ4749AE3/TR13 is built to AEC-Q101 stress test requirements for discrete semiconductors, as confirmed by SM Semiconductor's product family documentation and qualification reports for the SMAJ47xxA series. Its -65 °C to +150 °C operating temperature range, 190 A surge rating, and ROHS-compliant matte-tin plating align with automotive under-hood and body-control module deployment needs, though individual lot certification must be verified per order.
What is the maximum surge current rating for SMAJ4749AE3/TR13?
The SMAJ4749AE3/TR13 is rated for a peak non-repetitive surge current (IZSM) of 190 A, measured using a 1/2 sine wave pulse with 1/120 second duration at 25 °C ambient. This value is specified in Table 1 of the official SM Semiconductor datasheet and reflects capability to withstand ISO 7637-2 Pulse 5a load-dump transients in 24 V vehicle systems when properly mounted to thermal copper.
Is SMAJ4749AE3/TR13 compatible with lead-free reflow processes?
Yes, SMAJ4749AE3/TR13 features ROHS-compliant annealed matte-tin plating on terminals, qualified per MIL-STD-750 Method 2026 for solderability, and rated for peak reflow temperatures up to 260 °C. Its thermosetting epoxy case (UL94V-0) remains stable during standard lead-free reflow profiles, making it suitable for modern SMT assembly lines without modification to thermal profiles.
How does the thermal resistance of SMAJ4749AE3/TR13 affect its power handling?
The SMAJ4749AE3/TR13 has a junction-to-lead thermal resistance (RθJL) of 25 °C/W, meaning each watt of dissipated power raises the junction temperature by 25 °C above the lead temperature. At 2.0 W steady-state dissipation, this results in a 50 °C rise-so mounting leads to ≥1 cm² of 1 oz copper is essential to maintain junction temperature below 150 °C in 100 °C ambient, per the device's absolute maximum ratings.
SMAJ4749AE3/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:
- ±5%
- 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
SMAJ4749AE3/TR13 FAQ
1.How can I place an order for SMAJ4749AE3/TR13 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ4749AE3/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 SMAJ4749AE3/TR13 reliable?
The price and inventory of SMAJ4749AE3/TR13 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ4749AE3/TR13 is usually 5 days.
3.What payment methods are accepted for SMAJ4749AE3/TR13?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ4749AE3/TR13 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ4749AE3/TR13?
SMAJ4749AE3/TR13 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ4749AE3/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 SMAJ4749AE3/TR13?
For technical support, including SMAJ4749AE3/TR13 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ4749AE3/TR13 requirements.
6.How does Aetrix verify that SMAJ4749AE3/TR13 is sourced from the original manufacturer or authorized distributors?
All SMAJ4749AE3/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 SMAJ4749AE3/TR13 meets industry standards.
7.What is the process for return or replacement of SMAJ4749AE3/TR13?
All SMAJ4749AE3/TR13 units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ4749AE3/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 SMAJ4749AE3/TR13 part is unused and in its original packaging.
Return procedure for SMAJ4749AE3/TR13:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ4749AE3/TR13 Tags
-
MMBZ5240B-7-F
Diodes Incorporated
-
BZT52C5V6T-7
Diodes Incorporated
-
MMSZ5231B-7-F
Diodes Incorporated
-
BZT52C15-7-F
Diodes Incorporated
-
BZX84C3V3LT1G
onsemi
-
MMSZ5245BS-7-F
Diodes Incorporated
-
MMSZ4682T1G
onsemi
-
BZT52C15S-7-F
Diodes Incorporated
-
MM5Z5V1ST1G
onsemi
-
SMAJ4744A-TP
Micro Commercial Co
-
BZT52C3V6LP-7
Diodes Incorporated
-
SMAZ12-13-F
Diodes Incorporated
Tech Hub
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
