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Microchip Technology 1N5345A/TR12
- Part No.:
- 1N5345A/TR12
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- T-18, Axial
- Datasheet:
-
1N5345A/TR12.pdf
- Description:
- DIODE ZENER 8.7V 5W T18
- Quantity:
- Payment:
- Shipping:
Inventory:3,465
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Product details
Overview
1N5345A/TR12 from Microsemi is a 5 W axial-leaded silicon Zener diode with a nominal regulation voltage of 8.7 V, ±10% tolerance (A suffix), 150 mA maximum Zener current (IZM), and 2.0 Ω dynamic impedance (ZZ) at 150 mA test current. It operates across –65 °C to +150 °C and is used for precision voltage reference and overvoltage protection in industrial power supplies.
For engineers reviewing the 1N5345A/TR12 datasheet, 1N5345A/TR12 pinout, 1N5345A/TR12 application, or 1N5345A/TR12 equivalent, key selection criteria include Zener voltage tolerance, thermal resistance (25 °C/W junction-to-lead), surge current rating (545 A), voltage regulation (ΔVZ = 0.20 V), and RoHS-compliant matte-tin plating per MIL-STD-750.
Technical Context
This device functions as a two-terminal voltage regulator operating in reverse breakdown mode. Its Zener voltage is specified at 8.7 V ±10% under 150 mA DC test current (IZT), with dynamic impedance measured at 1 kHz AC superimposed on IZT.
Thermal design relies on junction-to-lead thermal resistance of 25 °C/W at 3/8″ (10 mm) lead length, enabling stable 5 W dissipation at TL ≤ 25 °C. Reverse leakage is limited to 10 µA at VR = 6.25 V, and forward voltage is ≤1.2 V at 1.0 A.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 8.7 V ±10% - defines regulated output voltage under nominal bias; tolerance impacts reference accuracy in feedback loops |
| Power Dissipation (Pd) | 5.0 W at TL ≤ 25 °C - sets maximum continuous power handling with adequate heatsinking at lead |
| Test Current (IZT) | 150 mA - operating point where VZ and ZZ are guaranteed; critical for stable regulation in shunt configurations |
| Dynamic Impedance (ZZ) | 2.0 Ω at IZT - determines output voltage variation under load transients; lower value improves regulation fidelity |
| Max Surge Current (IZSM) | 545 A (8.3 ms half-sine) - defines transient overvoltage clamping capability without failure |
| Voltage Regulation (ΔVZ) | 0.20 V - difference between VZ measured at 10% and 50% of IZM; quantifies line regulation performance |
| Reverse Leakage (IR) | 10 µA at VR = 6.25 V - limits standby power loss and ensures low-error biasing in high-impedance circuits |
Pinout & Package
Package: T-18 axial-leaded plastic encapsulated case per JEDEC DO-204AL; void-free UL94V-0 epoxy body; cathode indicated by band; leads plated with RoHS-compliant matte tin.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / low-voltage side in regulation | Connected to circuit ground or lower potential node when used in shunt regulation |
| Cathode | Reverse breakdown terminal / regulated output node | Banded end; connected to voltage rail being stabilized; carries full Zener current during regulation |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC-registered Zener family | Ensures standardized mechanical dimensions, marking, and reliability testing across manufacturers |
| Moisture sensitivity Level 1 | No dry pack required before PCB assembly; simplifies SMT and through-hole handling logistics |
| Nonsensitive to ESD (MIL-STD-750 Method 1020) | Eliminates need for special ESD handling during board assembly and field service |
| High surge current withstand (545 A) | Provides robust transient suppression in industrial environments with lightning or inductive switching noise |
| Low thermal resistance (25 °C/W) | Enables high-power operation with minimal heatsink volume when leads are properly terminated |
Applications
| Industrial Power Supply Reference | Overvoltage Clamp for 12 V Rail |
|---|---|
Use Scenario: Stabilizing feedback voltage in isolated flyback converters supplying 24 VDC to PLC I/O modules. IC Role / Device Role / Timing Role: Shunt voltage reference for TL431-based optocoupler feedback network. Use Value: Maintains ±10% output regulation across –40 °C to +85 °C ambient with <0.2 V drift over 150 mA load range. |
Use Scenario: Protecting microcontroller inputs and analog sensors on a 12 V automotive-grade control board. IC Role / Device Role / Timing Role: Standby clamping element placed between 12 V rail and ground. Use Value: Limits transient spikes to ≤8.7 V with 545 A peak surge capacity, preventing latch-up in downstream logic. |
| Programmable Current Source Bias | Temperature-Stable Reference for RTD Circuits |
Use Scenario: Setting bias current for a constant-current LED driver in outdoor signage. IC Role / Device Role / Timing Role: Voltage reference for op-amp-controlled MOSFET current sink. Use Value: Delivers stable 150 mA Zener current with <2 Ω dynamic impedance, minimizing current ripple under line variation. |
Use Scenario: Providing excitation voltage for 3-wire Pt100 RTD measurements in HVAC sensor nodes. IC Role / Device Role / Timing Role: Low-drift voltage source for Wheatstone bridge excitation. Use Value: Enables <0.2 V regulation delta across 0–100 °C ambient, supporting 0.1 °C temperature resolution. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N5345B/TR12 | ±5% VZ tolerance (vs. ±10% for 1N5345A/TR12); identical VZ, IZT, ZZ, and package | Higher reference accuracy required in closed-loop feedback or precision biasing | Select when tighter voltage stability outweighs cost premium and tolerance margin is constrained |
| MMBZ5236BS-7-F | Surface-mount SOD-123 package; 8.2 V nominal VZ; 200 mW power rating; ±5% tolerance | Space-constrained PCBs requiring automated placement; not suitable for 5 W continuous dissipation | Choose only for low-power signal-level clamping or biasing where thermal mass and surge immunity are secondary |
Compared with 1N5345B/TR12 and MMBZ5236BS-7-F, the 1N5345A/TR12 offers optimal balance of cost, axial-lead mechanical robustness, and 5 W surge-handling capability-making it preferred for industrial power rails where ±10% regulation tolerance is acceptable and lead-forming flexibility is needed.
Availability
1N5345A/TR12 is available at Aetrix Electronics and suitable for industrial power supplies, overvoltage protection circuits, and programmable current source biasing requiring stable component supply and long-term obsolescence management.
Supply support for 1N5345A/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 1N53xx series was designed specifically for ruggedized voltage regulation in harsh-environment power systems-emphasizing surge resilience, wide temperature operation, and JEDEC-standardized axial packaging for manual and automated assembly.
FAQ
What is the Zener voltage tolerance for 1N5345A/TR12?
The "A" suffix in 1N5345A/TR12 specifies a ±10% Zener voltage tolerance at 150 mA test current. This means the actual measured VZ falls between 7.83 V and 9.57 V at 25 °C. The tolerance directly affects system-level accuracy in voltage reference and feedback applications, and must be accounted for in worst-case design margins. 1N5345A/TR12 is not rated for tighter tolerance grades like ±5% (B suffix) or ±1% (D suffix).
Can 1N5345A/TR12 be used in surface-mount designs?
No-1N5345A/TR12 uses a T-18 axial-leaded package (JEDEC DO-204AL) and is not compatible with SMT reflow processes. It requires through-hole mounting with 3/8″ (10 mm) lead length for thermal derating compliance. For surface-mount equivalents, Microsemi offers the SMBJ5345B series, but those are distinct part numbers-not drop-in replacements for 1N5345A/TR12.
What is the maximum steady-state power dissipation of 1N5345A/TR12 on a standard FR4 PCB?
When mounted on FR4 with 1 oz copper, 4 mm² pads, and 1 mm × 25 mm traces, the 1N5345A/TR12 has a junction-to-ambient thermal resistance of 85 °C/W, limiting steady-state power to 1.47 W at TA = 25 °C. This is significantly lower than its 5 W rating at TL = 25 °C-so proper heatsinking via lead termination is essential to achieve full power capability. Derating curves in the datasheet must be followed.
Does 1N5345A/TR12 meet RoHS requirements?
Yes-1N5345A/TR12 is RoHS compliant, as confirmed by the "e3" designation in Microsemi's official documentation. Its leads use annealed matte-tin plating per MIL-STD-750 Method 2026, and the void-free epoxy body meets UL94V-0 flammability standards. No exemptions or lead-containing materials are used in its construction.
How is polarity marked on 1N5345A/TR12?
The cathode of 1N5345A/TR12 is identified by a single color band on the body. During operation, the banded end must be held at a higher potential than the anode (i.e., reverse-biased) to enable Zener breakdown and regulation. Incorrect polarity results in forward conduction (~1.2 V drop) and no voltage regulation. Marking is laser-etched or molded per JEDEC standards and remains legible after soldering.
1N5345A/TR12 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- T-18, Axial
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 8.7 V
- Tolerance:
- ±10%
- Power - Max:
- 5 W
- Impedance (Max) (Zzt):
- 2 Ohms
- Current - Reverse Leakage @ Vr:
- 10 µA @ 6.25 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.2 V @ 1 A
- Operating Temperature:
- -65°C ~ 150°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- T-18
1N5345A/TR12 FAQ
1.How can I place an order for 1N5345A/TR12 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N5345A/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 1N5345A/TR12 reliable?
The price and inventory of 1N5345A/TR12 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5345A/TR12 is usually 5 days.
3.What payment methods are accepted for 1N5345A/TR12?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5345A/TR12 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N5345A/TR12?
1N5345A/TR12 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N5345A/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 1N5345A/TR12?
For technical support, including 1N5345A/TR12 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5345A/TR12 requirements.
6.How does Aetrix verify that 1N5345A/TR12 is sourced from the original manufacturer or authorized distributors?
All 1N5345A/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 1N5345A/TR12 meets industry standards.
7.What is the process for return or replacement of 1N5345A/TR12?
All 1N5345A/TR12 units undergo pre-shipment inspection (PSI). If there is an issue with 1N5345A/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 1N5345A/TR12 part is unused and in its original packaging.
Return procedure for 1N5345A/TR12:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N5345A/TR12 Tags
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