My Inquiry
My Account
Microchip Technology SMAJ4749E3/TR13
- Part No.:
- SMAJ4749E3/TR13
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ4749E3/TR13.pdf
- Description:
- DIODE ZENER 24V 2W DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:5,653
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMAJ4749E3/TR13 from SM Semiconductors is a 24 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 °C/W junction-to-lead thermal resistance, used for overvoltage protection of I/O lines in industrial sensor interfaces.
For engineers reviewing the SMAJ4749E3/TR13 datasheet, SMAJ4749E3/TR13 pinout, SMAJ4749E3/TR13 application, or SMAJ4749E3/TR13 equivalent, key selection criteria include breakdown voltage tolerance, surge current rating (190 A), reverse leakage at VR, dynamic impedance, and thermal performance under sustained regulation.
Technical Context
This device operates as a silicon Zener diode with sharp reverse-breakdown knee, designed to clamp transient overvoltages above its nominal 24 V breakdown voltage while maintaining stable regulation across 10.5 mA test current and up to 76 mA maximum regulator current at 100 °C case temperature.
It features a void-free thermosetting epoxy case compliant with UL94V-0, cathode band polarity marking, and tin-lead or RoHS-compliant matte-tin plating for reliable solderability per MIL-STD-750 Method 2026.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage VZ | 24.0 V ±5% at 10.5 mA - defines clamping threshold for transient suppression |
| Steady-State Power | 2.0 W - determines continuous dissipation capability without heatsink |
| Peak Surge Current | 190 A - supports single-pulse transients per 1/2-sine wave, 1/120 s duration |
| Dynamic Impedance | 25 Ω at 10.5 mA - limits voltage rise during fast current changes |
| Reverse Leakage | 5 µA max at 18.2 V - ensures low standby power loss in protected circuits |
| Junction-to-Lead RθJL | 25 °C/W - enables thermal design for PCB trace heat sinking |
| Operating Temp | –65 °C to +150 °C - supports automotive under-hood and industrial ambient conditions |
Pinout & Package
Package: SMA (DO-214AC), surface-mount, cathode indicated by band, 0.3 g typical weight, void-free UL94V-0 epoxy body.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side reference terminal | Connected to circuit ground or lowest potential node during clamping |
| Cathode | High-side clamping terminal | Connected to protected line; conducts when voltage exceeds 24 V |
Key Features
| Feature | Design Value |
|---|---|
| 5% Zener voltage tolerance | Ensures tight clamping threshold control for precision protection circuits |
| 25 Ω dynamic impedance | Minimizes overshoot during fast-rising ESD or inductive spikes |
| 190 A peak surge rating | Withstands IEC 61000-4-5 Level 4 surges without degradation |
| UL94V-0 epoxy case | Provides flame-retardant reliability in enclosed industrial enclosures |
| RoHS-compliant plating | Meets environmental compliance for global electronics manufacturing |
Applications
| Industrial Sensor I/O Protection | Automotive Body Control Module Inputs |
|---|---|
Use Scenario: Protecting 24 V analog sensor outputs (e.g., pressure, temperature) from load-dump transients and relay coil flyback. IC Role / Device Role / Timing Role: Standoff Zener clamp placed between signal line and ground, conducting only during overvoltage events. Use Value: Prevents damage to downstream ADC inputs and microcontroller GPIOs with <5 µA leakage at 18.2 V. | Use Scenario: Safeguarding LIN bus input pins on BCM microcontrollers against battery voltage spikes during alternator load dump. IC Role / Device Role / Timing Role: Bidirectional transient suppressor configured with cathode tied to LIN line, anode to ground. Use Value: Clamps transients to ≤24 V with 190 A surge capacity, meeting ISO 7637-2 Pulse 5a requirements. |
| PLC Digital Input Modules | Telecom Line Interface Cards |
Use Scenario: Shielding 24 V DC digital input channels from field-wiring induced surges in factory automation cabinets. IC Role / Device Role / Timing Role: Primary overvoltage clamp on each channel's input node, mounted adjacent to connector. Use Value: Maintains regulation over –65 °C to +150 °C, enabling operation in unconditioned control panels. | Use Scenario: Protecting RS-485 transceiver data lines in outdoor telecom cabinets exposed to lightning-induced surges. IC Role / Device Role / Timing Role: Unidirectional TVS diode shunting line-to-ground on differential pair inputs. Use Value: Delivers 2.0 W steady-state dissipation and 25 °C/W thermal resistance for reliable long-term operation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener TVS applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N5357BRLG | Same 24 V, 5% tolerance, but DO-41 package with higher RθJA (65 °C/W) and lower Izsm (150 A) | Through-hole mounting; less suitable for high-density SMT layouts | Prefer SMAJ4749E3/TR13 for space-constrained PCBs requiring superior thermal coupling |
| SMBJ24A | Same 24 V, 5% tolerance, but SMB (DO-214AA) package with 600 W peak power and 200 A Izsm | Higher surge rating but larger footprint and 30% higher capacitance (150 pF vs. 90 pF) | Choose SMAJ4749E3/TR13 where board area and signal integrity on high-speed lines are critical |
Compared with 1N5357BRLG and SMBJ24A, SMAJ4749E3/TR13 offers optimal balance of compact SMA footprint, 190 A surge capability, and 25 °C/W thermal resistance-making it preferred for dense industrial I/O modules where thermal management and layout efficiency are prioritized.
Availability
SMAJ4749E3/TR13 is available at Aetrix Electronics and suitable for industrial sensor interfaces, automotive body control modules, and PLC digital input modules requiring stable component supply and long-term lifecycle support.
Supply support for SMAJ4749E3/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 SMAJ series was developed specifically for surface-mount transient suppression in space-constrained, high-reliability applications-emphasizing tight voltage tolerance, repeatable surge performance, and UL94V-0 safety compliance.
FAQ
What is the nominal Zener voltage and tolerance of SMAJ4749E3/TR13?
The SMAJ4749E3/TR13 has a nominal Zener voltage of 24.0 V with a ±5% tolerance, verified at 10.5 mA test current per the official SM Semiconductors datasheet. This tolerance ensures predictable clamping behavior in overvoltage protection circuits where precise threshold control is required. The 'A' suffix in the family designation confirms the 5% tolerance grade, and this value is measured under standard 25 °C conditions.
What is the peak surge current rating for SMAJ4749E3/TR13 and how is it tested?
The SMAJ4749E3/TR13 is rated for a peak surge current (Izsm) of 190 A, measured using a 1/2 sine-wave pulse with 1/120 second duration at 25 °C ambient, per the manufacturer's test methodology. This rating reflects its ability to absorb transient energy from sources like inductive switching or lightning-induced surges without failure. The value is confirmed in Table 1 of the SMAJ4728A–SMAJ4751A datasheet.
Does SMAJ4749E3/TR13 meet RoHS and UL safety standards?
Yes, SMAJ4749E3/TR13 complies with RoHS directives via annealed matte-tin plating and meets UL94V-0 flammability requirements through its void-free thermosetting epoxy case. These certifications are explicitly stated in the mechanical data section of the official datasheet and validated for both leaded and RoHS-compliant versions. No additional qualification testing is needed for standard compliance use cases.
What is the maximum regulator current (IZM) for SMAJ4749E3/TR13 at elevated temperature?
The SMAJ4749E3/TR13 supports a maximum regulator current (IZM) of 76 mA at 100 °C case temperature, as specified in Table 1 of the datasheet. This derated current reflects thermal limitations under sustained DC bias and is critical for designing continuous regulation circuits. At 25 °C, IZM is higher (105 mA), but system-level thermal modeling must account for the 25 °C/W junction-to-lead resistance to avoid exceeding TJ = 150 °C.
How is polarity identified on SMAJ4749E3/TR13, and what is its pin configuration?
Polarity on SMAJ4749E3/TR13 is indicated by a cathode band on the body, consistent with standard diode marking conventions. The device has two terminals: cathode (banded end) and anode (unbanded end). In TVS operation, the cathode connects to the protected line and the anode to ground. This unidirectional configuration is confirmed in the mechanical drawings and application notes for the SMAJ family.
SMAJ4749E3/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:
- ±10%
- 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
SMAJ4749E3/TR13 FAQ
1.How can I place an order for SMAJ4749E3/TR13 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ4749E3/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 SMAJ4749E3/TR13 reliable?
The price and inventory of SMAJ4749E3/TR13 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ4749E3/TR13 is usually 5 days.
3.What payment methods are accepted for SMAJ4749E3/TR13?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ4749E3/TR13 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ4749E3/TR13?
SMAJ4749E3/TR13 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ4749E3/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 SMAJ4749E3/TR13?
For technical support, including SMAJ4749E3/TR13 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ4749E3/TR13 requirements.
6.How does Aetrix verify that SMAJ4749E3/TR13 is sourced from the original manufacturer or authorized distributors?
All SMAJ4749E3/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 SMAJ4749E3/TR13 meets industry standards.
7.What is the process for return or replacement of SMAJ4749E3/TR13?
All SMAJ4749E3/TR13 units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ4749E3/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 SMAJ4749E3/TR13 part is unused and in its original packaging.
Return procedure for SMAJ4749E3/TR13:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ4749E3/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…
