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Microchip Technology 1N4749P/TR12
- Part No.:
- 1N4749P/TR12
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-204AL, DO-41, Axial
- Datasheet:
-
1N4749P/TR12.pdf
- Description:
- DIODE ZENER 24V 1W DO204AL
- Quantity:
- Payment:
- Shipping:
Inventory:4,751
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Product details
Overview
1N4749P/TR12 from Microsemi is a 1.0 W axial-lead silicon Zener diode with nominal Zener voltage of 24 V, ±5% tolerance (A-suffix), 10.5 mA test current (IZT), 25 Ω dynamic impedance (ZZT), and maximum reverse current of 5 μA at 18.2 V. It regulates voltage in power supply reference and overvoltage protection circuits across industrial temperature range.
For engineers reviewing the 1N4749P/TR12 datasheet, 1N4749P/TR12 pinout, 1N4749P/TR12 application, or 1N4749P/TR12 equivalent, key selection criteria include Zener voltage accuracy, thermal resistance (45 °C/W junction-to-lead), surge current rating (190 mA), RoHS-compliant "e3" plating option, and DO-41 package compatibility with standard axial-lead PCB layouts.
Technical Context
This device operates in reverse breakdown to maintain stable voltage across varying load currents (IZM = 190 mA at TA = 50 °C) and temperatures (–65 °C to +150 °C). Its 24 V Zener voltage exhibits a positive temperature coefficient near zero crossing, minimizing drift in precision references.
The DO-41 plastic package delivers 45 °C/W junction-to-lead thermal resistance at 10 mm lead length, enabling reliable 1.0 W dissipation at TL < 105 °C. Forward voltage is ≤1.2 V at 200 mA, confirming standard silicon PN junction behavior for bidirectional testing.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 24 V ±5% at IZT = 10.5 mA - defines regulation setpoint under standard test conditions |
| Power Dissipation | 1.0 W at TL < 105 °C (3/8″ lead length) - sets maximum continuous thermal load without derating |
| Dynamic Impedance | 25 Ω at IZT = 10.5 mA - determines output voltage variation under small-signal AC load changes |
| Max Reverse Current | 5 μA at VR = 18.2 V - confirms low leakage below knee voltage, critical for standby power integrity |
| Surge Current (ISM) | 190 mA (½-sine, 1/120 s) - supports transient overvoltage clamping in protection circuits |
| Thermal Resistance | 45 °C/W junction-to-lead - enables thermal design using lead conduction, not board convection |
| Operating Temp | –65 °C to +150 °C - validated for extended industrial and automotive under-hood environments |
Pinout & Package
DO-41 (DO-204AL) plastic axial-lead package with cathode indicated by color band. Leads are tin-lead or RoHS-compliant matte-tin plated, solderable per MIL-STD-750 Method 2026. Polarity: banded end is cathode (positive during Zener operation).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Non-banded lead | Connected to lower-potential node; carries forward current or reverse leakage path |
| Cathode | Banded lead | Connected to higher-potential node during Zener regulation; defines voltage reference point |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC-registered 1N47xxAP series | Guarantees mechanical and electrical interchangeability with legacy 1N47xx designs across manufacturers |
| Moisture Sensitivity Level 1 | Eliminates dry-pack requirement and floor-life constraints for SMT-compatible handling |
| RoHS-compliant "e3" option | Enables compliance with EU RoHS Directive 2011/65/EU without performance trade-offs |
| Nonsensitive to ESD | Withstands >4 kV HBM per MIL-STD-750 Method 1020 - reduces handling safeguards in assembly |
| Plastic vs. glass thermal advantage | 45 °C/W junction-to-lead (vs. ~60–70 °C/W for DO-35 glass) improves power handling in lead-conducted cooling |
Applications
| Power Supply Reference | Overvoltage Protection |
|---|---|
Use Scenario: Stable 24 V reference in linear regulator feedback networks or ADC reference dividers. IC Role / Device Role / Timing Role: Voltage reference element providing precise DC bias point independent of input ripple. Use Value: 5% tolerance and 25 Ω dynamic impedance ensure ≤120 mV output variation across 5–20 mA load current range. | Use Scenario: Clamping transient spikes on 24 V rail in industrial PLC I/O modules. IC Role / Device Role / Timing Role: Shunt protector diverting excess energy to ground when voltage exceeds 24 V threshold. Use Value: 190 mA surge rating handles 100 V/100 ns transients per IEC 61000-4-4 without degradation. |
| Voltage Monitor Threshold | Signal-Level Clamp |
Use Scenario: Undervoltage lockout (UVLO) trigger in battery-powered 24 V systems. IC Role / Device Role / Timing Role: Zener-based comparator input threshold defining minimum operational voltage. Use Value: –65 °C to +150 °C operating range ensures consistent trip point across extreme ambient conditions. | Use Scenario: Protecting analog sensor inputs from ESD-induced overvoltage in HVAC control boards. IC Role / Device Role / Timing Role: Low-capacitance shunt clamp limiting signal swing to safe levels. Use Value: 5 μA leakage at 18.2 V preserves high-impedance sensor node integrity during normal operation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4749A | No "P" suffix indicates glass DO-35 package; higher thermal resistance (~65 °C/W) | Less suitable for high-power-density layouts requiring lead-conducted heat removal | Select 1N4749P/TR12 when DO-41 mechanical robustness or lower thermal resistance is required |
| MMSZ4702T1G | Surface-mount SOD-123; 24 V, 500 mW; 30 Ω Zzt; RoHS-compliant | Not drop-in replaceable; requires PCB redesign; limited to lower power and surge capability | Choose MMSZ4702T1G only for space-constrained, automated SMT production where 1 W rating is unnecessary |
Compared with 1N4749A and MMSZ4702T1G, the 1N4749P/TR12 uniquely balances 1.0 W power handling, DO-41 axial reliability, and JEDEC-standardized interchangeability-making it optimal for through-hole industrial power rails where thermal margin and legacy compatibility are critical.
Availability
1N4749P/TR12 is available at Aetrix Electronics and suitable for industrial power supplies, overvoltage protection circuits, and voltage reference designs requiring stable component supply with full traceability and long-term lifecycle support.
Supply support for 1N4749P/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, RF, and timing solutions for aerospace, defense, and industrial markets.
The 1N47xxAP series was engineered for robust, standardized voltage regulation in mission-critical power systems where JEDEC compliance, thermal stability, and long-term availability are mandatory.
FAQ
What is the Zener voltage tolerance of the 1N4749P/TR12?
The 1N4749P/TR12 has a nominal Zener voltage of 24 V with ±5% tolerance, as indicated by the "A" suffix in its part number per JEDEC registration. This tolerance applies at 10.5 mA test current and 25 °C lead temperature. The "P" denotes plastic DO-41 packaging, and "TR12" specifies tape-and-reel packaging per EIA-296 standard. The 1N4749P/TR12 maintains this specification across its full operating temperature range.
Does the 1N4749P/TR12 meet RoHS requirements?
Yes, the 1N4749P/TR12 is offered in RoHS-compliant form with an "e3" suffix (e.g., 1N4749AP-e3/TR12), indicating annealed matte-tin plating per J-STD-609. The base 1N4749P/TR12 uses standard tin-lead terminations, but RoHS versions are fully interchangeable electrically and mechanically. Both variants comply with moisture sensitivity level 1 and require no dry pack.
What is the maximum steady-state power dissipation for the 1N4749P/TR12?
The 1N4749P/TR12 is rated for 1.0 W steady-state power dissipation at lead temperature (TL) < 105 °C with 10 mm lead length from body, or at ambient temperature (TA) < 45 °C when mounted on FR4 with specified copper pads. Derating is required above these temperatures per Figure 1 in the Microsemi datasheet. This rating is validated for continuous DC operation-not pulsed or surge conditions.
How does the thermal resistance of the 1N4749P/TR12 compare to glass-body Zeners?
The 1N4749P/TR12 has a junction-to-lead thermal resistance of 45 °C/W, significantly lower than the ~65–70 °C/W typical of glass-body 1N4749A (DO-35) devices. This 30–40% improvement enables higher sustained power handling in lead-conducted cooling configurations, such as chassis-mounted regulators or heatsink-attached leads, without exceeding junction temperature limits.
Can the 1N4749P/TR12 be used in surge protection applications?
Yes, the 1N4749P/TR12 supports surge current up to 190 mA (½-sine wave, 1/120 s duration) at 25 °C ambient, making it suitable for clamping fast transients in 24 V industrial systems. Its 24 V Zener voltage and low dynamic impedance ensure rapid response and minimal overshoot. For sustained overvoltage events, pairing with a current-limiting resistor is required to keep average power within the 1.0 W rating of the 1N4749P/TR12.
1N4749P/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:
- ±10%
- 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)
1N4749P/TR12 FAQ
1.How can I place an order for 1N4749P/TR12 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4749P/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 1N4749P/TR12 reliable?
The price and inventory of 1N4749P/TR12 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4749P/TR12 is usually 5 days.
3.What payment methods are accepted for 1N4749P/TR12?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4749P/TR12 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4749P/TR12?
1N4749P/TR12 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4749P/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 1N4749P/TR12?
For technical support, including 1N4749P/TR12 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4749P/TR12 requirements.
6.How does Aetrix verify that 1N4749P/TR12 is sourced from the original manufacturer or authorized distributors?
All 1N4749P/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 1N4749P/TR12 meets industry standards.
7.What is the process for return or replacement of 1N4749P/TR12?
All 1N4749P/TR12 units undergo pre-shipment inspection (PSI). If there is an issue with 1N4749P/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 1N4749P/TR12 part is unused and in its original packaging.
Return procedure for 1N4749P/TR12:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N4749P/TR12 Tags
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BZT52C5V6T-7
Diodes Incorporated
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MMSZ5231B-7-F
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BZX84C3V3LT1G
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MMSZ4682T1G
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MM5Z5V1ST1G
onsemi
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