My Inquiry
My Account
Microchip Technology 1N5345B/TR12
- Part No.:
- 1N5345B/TR12
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- T-18, Axial
- Datasheet:
-
1N5345B/TR12.pdf
- Description:
- DIODE ZENER 8.7V 5W T18
- Quantity:
- Payment:
- Shipping:
Inventory:7,099
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
1N5345B/TR12 from Microsemi is a 5 W axial-leaded silicon Zener diode with nominal regulation voltage of 8.7 V ±5%, 150 mA test current (IZT), 2.0 Ω dynamic impedance (ZZ), and 545 mA maximum Zener current (IZM) at 25 °C lead temperature. It operates from –65 °C to +150 °C and is used for precision voltage reference and overvoltage protection in DC power supplies.
For engineers reviewing the 1N5345B/TR12 datasheet, 1N5345B/TR12 pinout, 1N5345B/TR12 application, or 1N5345B/TR12 equivalent, key selection criteria include Zener voltage tolerance, thermal resistance (25 °C/W junction-to-lead), surge current rating (200 A), voltage regulation (ΔVZ = 0.20 V), and RoHS-compliant e3 marking compatibility.
Technical Context
This discrete Zener diode functions as a two-terminal voltage regulator in reverse-bias mode, maintaining stable output voltage across wide operating current (10–545 mA) and temperature (–65 to +150 °C) ranges. Its low dynamic impedance (2.0 Ω) and tight ±5% voltage tolerance ensure minimal deviation under load variation.
The device uses void-free thermosetting epoxy encapsulation (UL94V-0), tin-lead or matte-tin plating per MIL-STD-750 Method 2026, and features cathode band polarity marking. Thermal performance is defined at 3/8″ (10 mm) lead length from body (25 °C/W) or FR4 PCB mounting (85 °C/W).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 8.7 V ±5% - precise regulation point for 9 V rail clamping or reference generation |
| Test Current (IZT) | 150 mA - standardized bias point for VZ measurement and impedance characterization |
| Dynamic Impedance (ZZ) | 2.0 Ω - low AC resistance ensures stable voltage under varying load currents |
| Max Zener Current (IZM) | 545 mA - maximum continuous DC current at TL = 25 °C with adequate heat sinking |
| Voltage Regulation (ΔVZ) | 0.20 V - difference between VZ measured at 10% and 50% of IZM, indicating regulation linearity |
| Surge Current (IZSM) | 200 A - peak non-repetitive half-sine (8.3 ms) capability for transient suppression |
| Thermal Resistance | 25 °C/W junction-to-lead - enables high-power operation with simple lead-based heatsinking |
| Operating Temperature | –65 °C to +150 °C - suitable for industrial, automotive, and aerospace environments |
Pinout & Package
Package: Axial-leaded T-18 plastic case (void-free thermosetting epoxy, UL94V-0), cathode indicated by band. Leads are tin-lead or RoHS-compliant matte-tin plated, solderable per MIL-STD-750 Method 2026. Weight: 0.7 g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Zener cathode reference ground | Connected to circuit ground or lower-potential node; reverse-biased operation requires cathode at higher potential |
| Cathode | Zener regulation terminal / voltage reference output | Banded end; connected to regulated node; maintains 8.7 V relative to anode when reverse-biased above breakdown |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC-registered Zener | Complies with industry-standard 1N53xxB mechanical and electrical specifications for interchangeability |
| ±5% voltage tolerance (B suffix) | Reduces need for post-regulation trimming in mid-precision analog circuits |
| Moisture sensitivity Level 1 | No dry pack required prior to soldering-simplifies handling and assembly logistics |
| Nonsensitive to ESD (MIL-STD-750 Method 1020) | Eliminates need for special ESD handling during board assembly and testing |
| RoHS-compliant e3 option | Meets environmental compliance requirements without derating or performance trade-offs |
Applications
| Power Supply Overvoltage Clamp | DC Reference Voltage Generator |
|---|---|
Use Scenario: Protects downstream regulators and ICs from input voltage surges in 12 V DC power distribution systems. IC Role / Device Role / Timing Role: Zener diode operated in reverse breakdown to clamp voltage at 8.7 V. Use Value: Limits transient excursions to ≤9.1 V (8.7 V + ΔVZ), preventing damage to 10 V-rated components. | Use Scenario: Provides stable bias voltage for op-amp comparators and ADC reference inputs in sensor signal conditioning. IC Role / Device Role / Timing Role: Two-terminal passive voltage reference with low dynamic impedance. Use Value: Delivers <0.2 V regulation error across 15–500 mA load range, enabling 12-bit accuracy in analog front-ends. |
| Industrial Sensor Excitation | Fieldbus Interface Protection |
Use Scenario: Supplies constant 8.7 V excitation to resistive bridge sensors in PLC analog input modules. IC Role / Device Role / Timing Role: Precision shunt regulator maintaining fixed voltage despite supply ripple. Use Value: Ensures <±0.5% excitation stability over –40 to +85 °C ambient, improving sensor linearity. | Use Scenario: Shields RS-485 transceivers from induced surges on long-haul industrial communication lines. IC Role / Device Role / Timing Role: Primary clamping element in multi-stage TVS/Zener protection network. Use Value: Absorbs up to 200 A surge (8.3 ms) while limiting clamping voltage to ≤9.5 V, within transceiver safe operating area. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N5345B (bulk) | Identical electrical specs; differs only in packaging (TR12 = tape-and-reel, bulk has no reel) | No functional difference; TR12 enables automated pick-and-place assembly | Select 1N5345B/TR12 for SMT production; choose bulk for prototyping or hand-soldered repairs |
| MMBZ5236BS (Diodes Inc.) | Surface-mount SOD-123 package; 8.7 V ±5%, but lower power (500 mW vs. 5 W) and higher ZZ (10 Ω) | Not suitable for high-current regulation; limited to low-power bias/reference roles | Use MMBZ5236BS only where space-constrained PCB layout prohibits axial leads and power demand is <100 mA |
Compared with 1N5345B/TR12, the bulk version offers identical regulation performance but lacks tape-and-reel convenience for automated assembly, while MMBZ5236BS trades 10× lower power handling and poorer regulation for surface-mount compatibility.
Availability
1N5345B/TR12 is available at Aetrix Electronics and suitable for industrial power supplies, sensor interface modules, fieldbus protection circuits, and analog reference designs requiring stable component supply with full traceability and long-term lifecycle support.
Supply support for 1N5345B/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 1N53xxB series was designed as a JEDEC-standardized family of 5 W axial Zeners to replace legacy 1N47xx devices with improved thermal performance, tighter tolerances, and enhanced surge robustness for mission-critical power regulation.
FAQ
What is the Zener voltage tolerance of the 1N5345B/TR12?
The 1N5345B/TR12 has a Zener voltage tolerance of ±5%, as indicated by the "B" suffix in its part number. This means its nominal 8.7 V regulation voltage falls within 8.265 V to 9.135 V at 25 °C lead temperature and 150 mA test current. The tolerance remains valid across the full operating temperature range of –65 °C to +150 °C, per Microsemi's published electrical characteristics table.
Can the 1N5345B/TR12 be used in surface-mount designs?
No, the 1N5345B/TR12 is an axial-leaded T-18 package device and is not compatible with surface-mount assembly. For SMT equivalents, Microsemi offers the SMBJ5345B (DO-214AB) and SMBG5345B (DO-214AA) variants. These share identical electrical specs (8.7 V ±5%, 5 W) but require different PCB footprints and reflow profiles compared to the through-hole 1N5345B/TR12.
What is the maximum surge current rating for the 1N5345B/TR12?
The 1N5345B/TR12 has a maximum non-repetitive surge current (IZSM) rating of 200 A, specified as the peak value of an 8.3 ms half-sine waveform. This rating assumes proper PCB layout with adequate copper pour for thermal dissipation. Exceeding this surge level-even briefly-may cause irreversible junction damage, so external fusing or current-limiting must be verified in high-energy transient environments.
How does thermal resistance affect the 1N5345B/TR12's power handling?
The 1N5345B/TR12 has a junction-to-lead thermal resistance of 25 °C/W when mounted with 3/8″ (10 mm) lead length from body. At 25 °C ambient, this allows full 5 W dissipation; however, power must be derated linearly above 25 °C lead temperature. For example, at TL = 75 °C, max power drops to 3 W. PCB-mounted operation (junction-to-ambient = 85 °C/W) limits steady-state power to 1.47 W unless additional heatsinking is applied.
Is the 1N5345B/TR12 RoHS compliant?
Yes, the 1N5345B/TR12 is RoHS compliant, as confirmed by the "e3" suffix in its full manufacturer designation (1N5345B/TR12 e3). This indicates lead-free matte-tin plating on leads and compliance with EU Directive 2011/65/EU. No exemptions apply, and the device meets JEDEC J-STD-020 moisture sensitivity Level 1, eliminating dry-pack requirements before reflow soldering.
1N5345B/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:
- ±5%
- 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
1N5345B/TR12 FAQ
1.How can I place an order for 1N5345B/TR12 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N5345B/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 1N5345B/TR12 reliable?
The price and inventory of 1N5345B/TR12 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5345B/TR12 is usually 5 days.
3.What payment methods are accepted for 1N5345B/TR12?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5345B/TR12 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N5345B/TR12?
1N5345B/TR12 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N5345B/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 1N5345B/TR12?
For technical support, including 1N5345B/TR12 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5345B/TR12 requirements.
6.How does Aetrix verify that 1N5345B/TR12 is sourced from the original manufacturer or authorized distributors?
All 1N5345B/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 1N5345B/TR12 meets industry standards.
7.What is the process for return or replacement of 1N5345B/TR12?
All 1N5345B/TR12 units undergo pre-shipment inspection (PSI). If there is an issue with 1N5345B/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 1N5345B/TR12 part is unused and in its original packaging.
Return procedure for 1N5345B/TR12:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N5345B/TR12 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…
