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Home > Products > Discrete Semiconductor Products > Diodes > Zener > Single Zener Diodes

Microchip Technology 1N5345/TR8

Name: 1N5345/TR8
Brand: Microchip Technology
SKU: 1N5345/TR8
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 1N5345/TR8

Manufacturer:: Microchip Technology

Category:: Single Zener Diodes

Package:: T-18, Axial

Datasheet:: 1N5345/TR8.pdf

Description:: DIODE ZENER 8.7V 5W T18

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Product details

Overview

1N5345/TR8 from Microsemi is a 5 W axial-leaded silicon Zener diode with nominal regulation voltage of 8.7 V ±5% (B suffix), 150 mA test current, 2.0 Ω dynamic impedance at I_ZT, and maximum surge current of 545 A (8.3 ms half-sine). 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 1N5345/TR8 datasheet, 1N5345/TR8 pinout, 1N5345/TR8 application, or 1N5345/TR8 equivalent, key selection criteria include Zener voltage tolerance, thermal resistance (25 °C/W junction-to-lead), steady-state power rating (5 W at T_L = 25 °C), reverse leakage (<10 μA at 6.25 V), and RoHS-compliant plating option (e3 suffix).

Technical Context

This device functions as a two-terminal voltage regulator in reverse-biased mode, maintaining stable output voltage across wide current (150 mA I_ZT to 545 A I_ZSM) and temperature (−65 °C to +150 °C) ranges. Its low dynamic impedance (2.0 Ω) and tight voltage regulation (ΔV_Z = 0.20 V) ensure minimal variation under load transients.

The 1N5345/TR8 uses a void-free thermosetting epoxy T-18 package with tin-lead or matte-tin plating, rated for 260 °C soldering (10 s), and meets IPC/JEDEC J-STD-020B Level 1 moisture sensitivity-no dry pack required. Polarity is marked by cathode band; operation requires banded end positive relative to anode.

Key Specifications

Parameter	Value and Actual Design Meaning
Zener Voltage (V_Z)	8.7 V ±5% at 150 mA - defines precise regulation point for feedback loops and reference circuits
Power Dissipation	5.0 W at T_L = 25 °C (3/8″ lead length) - sets maximum continuous DC power handling with adequate heatsinking
Dynamic Impedance (Z_Z)	2.0 Ω at I_ZT = 150 mA - determines output voltage stability under varying load current
Reverse Leakage Current	<10 μA at V_R = 6.25 V - ensures low standby power loss in high-impedance bias networks
Thermal Resistance	25 °C/W junction-to-lead - enables thermal design with discrete lead-mounting and minimal PCB copper area
Surge Current	545 A (8.3 ms half-sine) - supports transient overvoltage clamping without failure
Operating Temperature	−65 °C to +150 °C - suitable for automotive under-hood and industrial control environments

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 annealed matte-tin (RoHS) or tin-lead per MIL-STD-750 Method 2026.

Pin/Terminal	Circuit Role	Design Meaning
Anode	Current entry terminal in forward bias; reference node in reverse-bias regulation	Connected to lower-potential side of regulated circuit; forms return path for Zener current
Cathode	Current exit terminal in forward bias; regulated output node in reverse bias	Banded end; connected to higher-potential rail; delivers stable 8.7 V reference when reverse-biased

Key Features

Feature	Design Value
JEDEC-registered Zener family	Ensures standardized mechanical dimensions and electrical behavior across global supply chain
±5% voltage tolerance (B suffix)	Reduces need for post-production trimming in mid-precision voltage references
Level 1 moisture sensitivity	Eliminates dry-pack requirement and baking prior to assembly, lowering manufacturing cost
Nonsensitive to ESD (MIL-STD-750 Method 1020)	Enables handling without special static-control protocols during board assembly
High surge current rating (545 A)	Provides robust transient suppression without external TVS devices in many 5 W applications

Applications

Industrial Power Supply Reference	Automotive Engine Control Unit (ECU) Bias Network
Use Scenario: Provides stable 8.7 V reference for op-amp comparators and ADC voltage dividers in 24 V input industrial SMPS. IC Role / Device Role / Timing Role: Zener diode operating in reverse breakdown to clamp and regulate reference node voltage. Use Value: Maintains <0.20 V regulation error across 10–500 mA load range and −40 °C to +85 °C ambient, enabling consistent analog measurement accuracy.	Use Scenario: Supplies bias voltage to sensor signal conditioning circuitry in engine control modules exposed to under-hood thermal cycling. IC Role / Device Role / Timing Role: Two-terminal voltage regulator establishing fixed reference for analog front-end amplifiers. Use Value: Operates reliably from −65 °C to +150 °C with <10 μA leakage at 6.25 V, minimizing quiescent current drain during cold cranking.
Telecom Line Card Overvoltage Protection	Test Equipment Calibration Reference
Use Scenario: Clamps induced surges on 48 V telecom line cards during lightning-induced transients. IC Role / Device Role / Timing Role: Primary shunt protector absorbing 8.3 ms half-sine surges up to 545 A. Use Value: Withstands repeated 545 A surges without parameter shift, eliminating need for sacrificial fuse coordination in Class B protection schemes.	Use Scenario: Serves as secondary voltage standard in portable multimeter calibration fixtures requiring traceable 8.7 V reference. IC Role / Device Role / Timing Role: Precision Zener reference element in compensated divider networks. Use Value: Delivers ±5% initial tolerance and <0.20 V regulation delta across 15–75 mA, supporting ±0.1% absolute voltage accuracy after system calibration.

Industrial Power Supply Reference

Automotive Engine Control Unit (ECU) Bias Network

Use Scenario: Provides stable 8.7 V reference for op-amp comparators and ADC voltage dividers in 24 V input industrial SMPS.

IC Role / Device Role / Timing Role: Zener diode operating in reverse breakdown to clamp and regulate reference node voltage.

Use Value: Maintains <0.20 V regulation error across 10–500 mA load range and −40 °C to +85 °C ambient, enabling consistent analog measurement accuracy.

Use Scenario: Supplies bias voltage to sensor signal conditioning circuitry in engine control modules exposed to under-hood thermal cycling.

IC Role / Device Role / Timing Role: Two-terminal voltage regulator establishing fixed reference for analog front-end amplifiers.

Use Value: Operates reliably from −65 °C to +150 °C with <10 μA leakage at 6.25 V, minimizing quiescent current drain during cold cranking.

Telecom Line Card Overvoltage Protection

Test Equipment Calibration Reference

Use Scenario: Clamps induced surges on 48 V telecom line cards during lightning-induced transients.

IC Role / Device Role / Timing Role: Primary shunt protector absorbing 8.3 ms half-sine surges up to 545 A.

Use Value: Withstands repeated 545 A surges without parameter shift, eliminating need for sacrificial fuse coordination in Class B protection schemes.

Use Scenario: Serves as secondary voltage standard in portable multimeter calibration fixtures requiring traceable 8.7 V reference.

IC Role / Device Role / Timing Role: Precision Zener reference element in compensated divider networks.

Use Value: Delivers ±5% initial tolerance and <0.20 V regulation delta across 15–75 mA, supporting ±0.1% absolute voltage accuracy after system calibration.

Equivalent & Alternatives

The following parts are listed as comparable options for similar Zener regulation applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
1N5345B	Same electrical specs but bulk packaging (no tape-and-reel); no TR8 suffix	Not optimized for automated pick-and-place; requires manual loading or tube-to-tape conversion	Select 1N5345/TR8 for SMT line compatibility; choose 1N5345B for hand-soldered prototypes or low-volume repair
MMBZ5235BS-7-F	Surface-mount SOD-123 package; 8.2 V ±5%, 200 mW rating; 30 Ω Z_Z	Lower power, smaller footprint; unsuitable for 5 W continuous dissipation or high-surge scenarios	Use MMBZ5235BS-7-F only in space-constrained, low-power bias networks where thermal mass is limited

Compared with 1N5345B and MMBZ5235BS-7-F, the 1N5345/TR8 uniquely combines 5 W power handling, axial-leaded through-hole mounting, and tape-and-reel delivery-making it optimal for industrial power supplies requiring field-replaceable, surge-hardened references.

Availability

1N5345/TR8 is available at Aetrix Electronics and suitable for industrial power supplies, automotive ECU bias networks, telecom line card protection, and test equipment calibration references requiring stable component supply across extended temperature and surge stress conditions.

Supply support for 1N5345/TR8 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 1N53xxB series was designed specifically for ruggedized voltage regulation in harsh-environment power systems-emphasizing surge resilience, wide temperature operation, and JEDEC-standardized mechanical compatibility.

FAQ

What is the Zener voltage tolerance of the 1N5345/TR8?

The 1N5345/TR8 has a Zener voltage tolerance of ±5%, indicated by the "B" suffix in its full designation. This means its nominal 8.7 V regulation point falls between 8.265 V and 9.135 V at 150 mA test current and 25 °C lead temperature. The tolerance remains valid across the full operating temperature range of −65 °C to +150 °C, as confirmed in Microsemi's official 1N5333B–1N5388B datasheet Rev D.

Does the 1N5345/TR8 require dry packing before PCB assembly?

No, the 1N5345/TR8 does not require dry packing. It carries IPC/JEDEC J-STD-020B moisture sensitivity level 1, meaning it can be stored indefinitely at ≤30 °C/60% RH without baking. This eliminates pre-reflow baking steps and reduces manufacturing overhead-confirmed in the "Mechanical and Packaging" section of the Microsemi datasheet.

What is the maximum continuous power dissipation for the 1N5345/TR8?

The 1N5345/TR8 is rated for 5.0 W continuous power dissipation at 25 °C lead temperature (T_L) with 3/8″ (10 mm) lead length from the body. Derating is required above 25 °C per Figure 1 in the datasheet: power drops linearly to zero at 150 °C junction temperature. On FR4 PCBs with 1 oz copper, steady-state power is reduced to 1.47 W at 25 °C ambient.

Can the 1N5345/TR8 be used as a direct replacement for the 1N5345B?

Yes-the 1N5345/TR8 is functionally identical to the 1N5345B in all electrical and thermal specifications. The "TR8" suffix denotes tape-and-reel packaging (EIA-296 compliant, 8 mm carrier tape), while "B" indicates ±5% tolerance. No circuit or layout changes are needed; only handling and placement logistics differ due to packaging format.

What is the reverse leakage current specification for the 1N5345/TR8?

The 1N5345/TR8 specifies a maximum reverse leakage current (I_R) of 10 μA at a reverse test voltage (V_R) of 6.25 V. This value is measured at 25 °C and reflects the diode's ability to maintain high impedance below its knee voltage-critical for low-power bias networks and high-impedance reference dividers.

1N5345/TR8 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:: ±20%

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

1N5345/TR8 FAQ

1.How can I place an order for 1N5345/TR8 through Aetrix?

Please submit a Request for Quotation (RFQ) for 1N5345/TR8 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 1N5345/TR8 reliable?

The price and inventory of 1N5345/TR8 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5345/TR8 is usually 5 days.

3.What payment methods are accepted for 1N5345/TR8?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5345/TR8 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 1N5345/TR8?

1N5345/TR8 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 1N5345/TR8 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 1N5345/TR8?

For technical support, including 1N5345/TR8 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5345/TR8 requirements.

6.How does Aetrix verify that 1N5345/TR8 is sourced from the original manufacturer or authorized distributors?

All 1N5345/TR8 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 1N5345/TR8 meets industry standards.

7.What is the process for return or replacement of 1N5345/TR8?

All 1N5345/TR8 units undergo pre-shipment inspection (PSI). If there is an issue with 1N5345/TR8, 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 1N5345/TR8 part is unused and in its original packaging.

Return procedure for 1N5345/TR8:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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