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Microchip Technology 1N4749CPE3/TR12
- Part No.:
- 1N4749CPE3/TR12
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-204AL, DO-41, Axial
- Datasheet:
-
1N4749CPE3/TR12.pdf
- Description:
- DIODE ZENER 24V 1W DO204AL
- Quantity:
- Payment:
- Shipping:
Inventory:6,198
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Product details
Overview
1N4749CPE3/TR12 from Microsemi is a 24 V, ±2% tolerance, 1 W silicon Zener diode in DO-41 plastic package, rated for 10.5 mA test current (IZT), 25 Ω dynamic impedance (ZZT), and 750 mA maximum regulator current (IZM) at 50°C. It provides precision voltage regulation in power supply reference and overvoltage protection circuits.
For engineers reviewing the 1N4749CPE3/TR12 datasheet, 1N4749CPE3/TR12 pinout, 1N4749CPE3/TR12 application, or 1N4749CPE3/TR12 equivalent, key selection criteria include Zener voltage tolerance (±2%), thermal resistance (45°C/W junction-to-lead), surge current rating (750 mA), RoHS-compliant matte-tin plating, and tape-and-reel packaging (TR12).
Technical Context
This device operates in reverse-biased breakdown mode to maintain stable output voltage across varying load and line conditions. Its 24 V nominal Zener voltage exhibits low temperature coefficient near zero crossing, with specified knee impedance (ZZK = 38 Ω at IZK = 0.25 mA) ensuring sharp regulation onset.
Designed for axial-lead mounting on FR4 PCBs, it delivers 1.0 W steady-state dissipation at lead temperature <105°C (3/8" from body) or ambient <45°C, with thermal resistance of 105°C/W junction-to-ambient under defined copper pad conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (Vz) | 24 V ±2% at IZT = 10.5 mA - ensures tight regulation tolerance for reference circuits |
| Power Dissipation | 1.0 W at TL < 105°C - defines maximum continuous thermal load with proper lead heatsinking |
| Dynamic Impedance (ZZT) | 25 Ω at IZT = 10.5 mA - determines output voltage variation under load current changes |
| Max Regulator Current (IZM) | 750 mA at TA = 50°C - sets upper limit for sustained Zener conduction without thermal runaway |
| Reverse Leakage (IR) | 5 μA max at VR = 18.2 V - confirms low off-state current below breakdown threshold |
| Forward Voltage (VF) | 1.2 V max at IF = 200 mA - defines forward conduction drop during transient polarity reversal |
| Thermal Resistance | 45°C/W junction-to-lead (3/8" lead length) - enables thermal design using lead as primary heat path |
Pinout & Package
DO-41 (DO-204AL) plastic axial-leaded package with cathode indicated by color band; leads are tin-lead or RoHS-compliant matte-tin plated, solderable per MIL-STD-750 Method 2026.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Non-banded end | Connected to lower-potential node; carries forward current or sinks reverse leakage |
| Cathode | Banded end | Connected to higher-potential node; conducts reverse current during Zener regulation |
Key Features
| Feature | Design Value |
|---|---|
| ±2% Zener voltage tolerance (C suffix) | Enables high-accuracy voltage references without post-calibration in industrial power supplies |
| RoHS-compliant "e3" suffix | Meets global environmental compliance requirements with annealed matte-tin plating |
| Moisture sensitivity Level 1 | Eliminates dry-pack requirement and floor-life constraints for SMT assembly prep |
| Nonsensitive to ESD (MIL-STD-750 Method 1020) | Reduces handling precautions and eliminates need for ESD-protective packaging in logistics |
| Tape-and-reel packaging (TR12) | Supports automated pick-and-place assembly with standard EIA-296 carrier tape format |
Applications
| Industrial Power Supply Reference | Overvoltage Clamp for Microcontroller I/O |
|---|---|
Use Scenario: Stabilizing feedback voltage in isolated DC-DC converter secondary-side regulation. IC Role / Device Role / Timing Role: Precision shunt reference providing 24 V基准 for optocoupler feedback loop. Use Value: ±2% tolerance ensures output voltage accuracy within ±0.5% over line/load/temperature, meeting EN 61000-3-2 compliance. | Use Scenario: Protecting 3.3 V or 5 V GPIO pins from transient overvoltage events. IC Role / Device Role / Timing Role: Fast-acting shunt clamp limiting voltage to 24 V before damage threshold. Use Value: 750 mA IZM and 25 Ω ZZT enable robust clamping of 100 ns–1 µs surges without thermal failure. |
| Automotive Sensor Biasing | Programmable Current Source Reference |
Use Scenario: Providing stable bias voltage for analog sensor signal conditioning in engine control units. IC Role / Device Role / Timing Role: Temperature-stable Zener reference for op-amp gain-setting networks. Use Value: Low tempco near 24 V and 45°C/W thermal resistance ensure <±10 mV drift over –40°C to +125°C ambient. | Use Scenario: Setting precise current in constant-current LED driver or laser diode bias circuit. IC Role / Device Role / Timing Role: Shunt-regulated voltage source feeding current-sense resistor network. Use Value: 25 Ω ZZT and 10.5 mA IZT allow sub-1% current regulation accuracy with minimal external components. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4749A | Same 24 V nominal, but ±5% tolerance (A suffix) instead of ±2% | Acceptable where tighter regulation not required; lower cost | Select when system-level calibration compensates for voltage variance |
| MMSZ4704T1G | Surface-mount SOD-123 package; same 24 V ±5%, 1 W rating, but 300 mA IZM | Used in space-constrained PCBs requiring automated SMT placement | Choose for high-density layouts where axial leads are impractical |
Compared with 1N4749A and MMSZ4704T1G, the 1N4749CPE3/TR12 offers superior voltage accuracy (±2% vs ±5%) and higher surge capability (750 mA vs 300 mA), making it optimal for precision reference and high-energy clamp roles where axial mounting is acceptable.
Availability
1N4749CPE3/TR12 is available at Aetrix Electronics and suitable for industrial power supplies, automotive sensor interfaces, programmable current sources, and overvoltage protection circuits requiring stable component supply with full traceability and long-term lifecycle support.
Supply support for 1N4749CPE3/TR12 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
Microsemi (now part of Microchip Technology) is a U.S.-based semiconductor company specializing in high-reliability analog, mixed-signal, and RF solutions for aerospace, defense, and industrial markets.
The 1N47xx series was designed specifically for general-purpose, high-stability Zener regulation in harsh-environment power systems where reliability, thermal robustness, and JEDEC-standard compatibility are critical.
FAQ
What is the Zener voltage tolerance of the 1N4749CPE3/TR12?
The 1N4749CPE3/TR12 has a Zener voltage tolerance of ±2%, denoted by the "C" suffix in the part number. This means its nominal 24 V Zener voltage is guaranteed between 23.52 V and 24.48 V at the specified test current of 10.5 mA and lead temperature of 25°C, enabling high-accuracy voltage referencing in precision analog circuits.
Does the 1N4749CPE3/TR12 meet RoHS requirements?
Yes, the 1N4749CPE3/TR12 meets RoHS requirements, as confirmed by the "e3" suffix in its designation. It features RoHS-compliant annealed matte-tin plating on its axial leads and is manufactured using lead-free processes compliant with Directive 2011/65/EU, with full material declarations available upon request.
What is the maximum surge current rating for the 1N4749CPE3/TR12?
The 1N4749CPE3/TR12 has a maximum surge current (ISM) rating of 750 mA, measured using a ½ sine-wave pulse of 1/120 second duration at 25°C ambient. This rating supports reliable transient overvoltage clamping in power supply input stages and I/O protection circuits without degradation.
How does the thermal resistance of the 1N4749CPE3/TR12 affect PCB layout?
The 1N4749CPE3/TR12 has a junction-to-lead thermal resistance of 45°C/W at 3/8" (10 mm) lead length from the body. To maintain safe operation, PCB traces connected to its leads should be wide and short, and the device must be mounted with ≥10 mm of straight lead length outside the board edge to leverage the lead as a heatsink-critical for sustaining 1 W dissipation.
Is tape-and-reel packaging included with the 1N4749CPE3/TR12?
Yes, the "TR12" suffix in 1N4749CPE3/TR12 explicitly indicates EIA-296 standard tape-and-reel packaging, optimized for automated SMT placement equipment. Each reel contains 1,000 units, with carrier tape conforming to industry-standard pocket dimensions and cover tape peel strength specifications.
1N4749CPE3/TR12 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- DO-204AL, DO-41, Axial
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 24 V
- Tolerance:
- ±2%
- Power - Max:
- 1 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:
- -65°C ~ 150°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-204AL (DO-41)
1N4749CPE3/TR12 FAQ
1.How can I place an order for 1N4749CPE3/TR12 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4749CPE3/TR12 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 1N4749CPE3/TR12 reliable?
The price and inventory of 1N4749CPE3/TR12 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4749CPE3/TR12 is usually 5 days.
3.What payment methods are accepted for 1N4749CPE3/TR12?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4749CPE3/TR12 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4749CPE3/TR12?
1N4749CPE3/TR12 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4749CPE3/TR12 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 1N4749CPE3/TR12?
For technical support, including 1N4749CPE3/TR12 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4749CPE3/TR12 requirements.
6.How does Aetrix verify that 1N4749CPE3/TR12 is sourced from the original manufacturer or authorized distributors?
All 1N4749CPE3/TR12 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 1N4749CPE3/TR12 meets industry standards.
7.What is the process for return or replacement of 1N4749CPE3/TR12?
All 1N4749CPE3/TR12 units undergo pre-shipment inspection (PSI). If there is an issue with 1N4749CPE3/TR12, 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 1N4749CPE3/TR12 part is unused and in its original packaging.
Return procedure for 1N4749CPE3/TR12:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N4749CPE3/TR12 Tags
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MM5Z5V1ST1G
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