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Microchip Technology 1N4745AP/TR12
- Part No.:
- 1N4745AP/TR12
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-204AL, DO-41, Axial
- Datasheet:
-
1N4745AP/TR12.pdf
- Description:
- DIODE ZENER 16V 1W DO204AL
- Quantity:
- Payment:
- Shipping:
Inventory:2,576
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Product details
Overview
1N4745AP/TR12 from Microsemi is a 16 V, 1 W silicon Zener diode in DO-41 plastic package with ±5% voltage tolerance, 15.5 mA test current (IZT), and 16 Ω dynamic impedance (ZZT) at IZT. It regulates voltage across industrial power supplies, reference circuits, and overvoltage protection stages where stable 16 V clamping is required.
For engineers reviewing the 1N4745AP/TR12 datasheet, 1N4745AP/TR12 pinout, 1N4745AP/TR12 application, or 1N4745AP/TR12 equivalent, key selection criteria include Zener voltage accuracy, thermal resistance (45 °C/W junction-to-lead), surge current rating (285 mA), reverse leakage (5 µA @ 12.2 V), and RoHS-compliant "e3" plating compatibility with automated assembly.
Technical Context
This device operates in reverse breakdown to maintain a stable 16 V reference across variable load currents from 1.0 mA to 285 mA. Its 45 °C/W junction-to-lead thermal resistance enables reliable 1 W dissipation at lead temperature ≤105 °C with 3/8″ (10 mm) lead length from body.
The 1N4745AP/TR12 exhibits a sharp Zener knee with 0.5 mA test current (IZK) and 57 Ω knee impedance (ZZK), ensuring low-noise regulation under light-load conditions. Polarity is marked by cathode band; operation requires cathode positive relative to anode for regulation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 16 V ±5% at 15.5 mA - defines nominal regulation point with tight production control for reference stability |
| Power Dissipation | 1.0 W at TL < 105 °C - supports continuous operation in compact PCB layouts with adequate lead heatsinking |
| Dynamic Impedance (ZZT) | 16 Ω @ IZT = 15.5 mA - ensures minimal output voltage variation under changing load current |
| Reverse Leakage Current | 5 µA max @ VR = 12.2 V - guarantees low standby power loss in precision bias networks |
| Surge Current (ISM) | 285 mA (½-sine, 1/120 s) - withstands transient overvoltage events without degradation |
| Thermal Resistance | 45 °C/W junction-to-lead - enables thermal design using standard axial-lead mounting without forced cooling |
| Operating Temperature | –65 °C to +150 °C - suitable for automotive under-hood and industrial ambient environments |
Pinout & Package
DO-41 (DO-204AL) plastic axial-leaded package with void-free UL94V-0 epoxy body and tin-lead or RoHS-compliant matte-tin plating. Cathode identified by colored band.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Reference ground node | Connected to circuit common; reverse-biased operation requires this terminal negative relative to cathode |
| Cathode | Regulated output node | Banded end; held at stable 16 V above anode during breakdown conduction |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC-registered 1N47xxAP series | Industry-standard footprint and electrical behavior enabling direct replacement in legacy designs |
| Moisture Sensitivity Level 1 | No dry pack required - simplifies SMT handling and eliminates bake-out prior to assembly |
| Nonsensitive to ESD (MIL-STD-750 Method 1020) | Robust handling in manufacturing without special static controls beyond standard precautions |
| RoHS-compliant "e3" suffix option | Meets global environmental compliance requirements while maintaining identical electrical performance |
| Plastic P-suffix construction | Lower thermal resistance vs. glass-body G-suffix variants - improves power handling in same JEDEC outline |
Applications
| Power Supply Voltage Reference | Overvoltage Clamp Circuit |
|---|---|
Use Scenario: Stabilizing feedback node in linear regulator or switching converter error amplifier. IC Role / Device Role / Timing Role: Provides precise 16 V reference to set output voltage via resistor divider. Use Value: Maintains ±5% regulation accuracy across –65 °C to +150 °C, reducing calibration drift in unregulated supplies. | Use Scenario: Protecting microcontroller I/O pins from transient voltage spikes on sensor lines. IC Role / Device Role / Timing Role: Shunts excess energy to ground when line voltage exceeds 16 V. Use Value: 285 mA surge rating absorbs 1/120 s transients without failure, extending system reliability. |
| DC-DC Converter Feedback Divider | Industrial Sensor Bias Network |
Use Scenario: Setting regulated 16 V rail for op-amp biasing in isolated DC-DC modules. IC Role / Device Role / Timing Role: Acts as stable voltage node in resistive divider network driving optocoupler input. Use Value: 16 Ω dynamic impedance minimizes output voltage shift under varying optocoupler LED current. | Use Scenario: Providing excitation voltage for RTD or bridge-based pressure sensors. IC Role / Device Role / Timing Role: Supplies low-drift, low-noise 16 V bias independent of supply rail fluctuations. Use Value: 5 µA max reverse leakage prevents loading of high-impedance sensor outputs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4745A | No "TR12" tape-and-reel packaging; bulk or ammo pack only | Same electrical specs but unsuitable for automated pick-and-place | Select 1N4745AP/TR12 for SMT production; use 1N4745A for prototyping or manual assembly |
| MMBZ5245B | SOT-23 surface-mount package; 16 V ±5%, 200 mW rating | Lower power handling limits use to signal-level clamping, not 1 W regulation | Choose MMBZ5245B only for space-constrained low-power biasing where 1 W dissipation is unnecessary |
Compared with 1N4745A and MMBZ5245B, the 1N4745AP/TR12 uniquely combines 1 W power capability, DO-41 axial-leaded manufacturability, and tape-and-reel delivery-making it optimal for high-reliability industrial power rails requiring proven thermal performance and automated assembly support.
Availability
1N4745AP/TR12 is available at Aetrix Electronics and suitable for industrial power supplies, sensor interface modules, and embedded controller protection circuits requiring stable component supply and long-term lifecycle continuity.
Supply support for 1N4745AP/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 and mixed-signal components for aerospace, defense, and industrial markets.
The 1N4745AP/TR12 belongs to Microsemi's legacy 1N47xxAP Zener diode family, engineered for robust voltage regulation in harsh-environment power systems where thermal stability and long-term parametric consistency are critical.
FAQ
What is the Zener voltage tolerance for 1N4745AP/TR12?
The 1N4745AP/TR12 has a nominal Zener voltage of 16 V with a ±5% tolerance, as indicated by the "A" suffix per JEDEC registration. This means the actual measured VZ falls between 15.2 V and 16.8 V at 15.5 mA test current and 25 °C lead temperature, supporting predictable design margins in reference and clamp applications.
Does 1N4745AP/TR12 require dry packing before reflow soldering?
No, the 1N4745AP/TR12 is rated Moisture Sensitivity Level 1 per IPC/JEDEC J-STD-020B, meaning it may be stored and processed without dry packing or baking. Its plastic DO-41 package is inherently moisture-resistant, eliminating pre-reflow bake steps and reducing manufacturing overhead in high-volume assembly.
What is the maximum surge current rating for 1N4745AP/TR12?
The 1N4745AP/TR12 supports a maximum non-repetitive surge current (ISM) of 285 mA, measured using a ½-sine wave pulse of 1/120 second duration at 25 °C ambient. This rating enables reliable transient suppression in power-line protection and input-stage clamping without permanent parameter shift.
How does the thermal resistance of 1N4745AP/TR12 affect PCB layout?
The 1N4745AP/TR12 has a junction-to-lead thermal resistance of 45 °C/W, meaning its safe 1 W operation depends on effective heat conduction through its axial leads. Layout should maintain ≥10 mm straight lead length from body to board entry point and avoid excessive copper removal near solder joints to preserve thermal path integrity.
Is 1N4745AP/TR12 RoHS compliant?
Yes, the "e3" suffix in 1N4745AP/TR12 confirms RoHS compliance per EU Directive 2011/65/EU. The device uses annealed matte-tin plating instead of tin-lead, meeting lead-free soldering requirements while retaining full electrical and thermal equivalence to legacy Sn/Pb versions.
1N4745AP/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):
- 16 V
- Tolerance:
- ±5%
- Power - Max:
- 1 W
- Impedance (Max) (Zzt):
- 16 Ohms
- Current - Reverse Leakage @ Vr:
- 5 µA @ 12.2 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)
1N4745AP/TR12 FAQ
1.How can I place an order for 1N4745AP/TR12 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4745AP/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 1N4745AP/TR12 reliable?
The price and inventory of 1N4745AP/TR12 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4745AP/TR12 is usually 5 days.
3.What payment methods are accepted for 1N4745AP/TR12?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4745AP/TR12 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4745AP/TR12?
1N4745AP/TR12 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4745AP/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 1N4745AP/TR12?
For technical support, including 1N4745AP/TR12 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4745AP/TR12 requirements.
6.How does Aetrix verify that 1N4745AP/TR12 is sourced from the original manufacturer or authorized distributors?
All 1N4745AP/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 1N4745AP/TR12 meets industry standards.
7.What is the process for return or replacement of 1N4745AP/TR12?
All 1N4745AP/TR12 units undergo pre-shipment inspection (PSI). If there is an issue with 1N4745AP/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 1N4745AP/TR12 part is unused and in its original packaging.
Return procedure for 1N4745AP/TR12:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N4745AP/TR12 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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MMSZ4682T1G
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BZT52C15S-7-F
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MM5Z5V1ST1G
onsemi
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SMAZ12-13-F
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