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Microchip Technology 1N6345US/TR
- Part No.:
- 1N6345US/TR
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- SQ-MELF, B
- Datasheet:
-
1N6345US/TR.pdf
- Description:
- DIODE ZENER 75V 500MW SQ-MELF
- Quantity:
- Payment:
- Shipping:
Inventory:100
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Product details
Overview
1N6345US/TR from Microsemi is a military-qualified, voidless hermetically sealed glass Zener diode with nominal 75 V zener voltage, ±5% tolerance, 0.5 W power rating, and B-SQ MELF surface-mount package. It delivers stable voltage regulation across -65°C to +175°C for high-reliability power supply reference and overvoltage protection in aerospace avionics and radiation-hardened systems.
For engineers reviewing the 1N6345US/TR datasheet, 1N6345US/TR pinout, 1N6345US/TR application, or 1N6345US/TR equivalent, key selection criteria include its MIL-PRF-19500/533 qualification (JAN/JANTXV levels), 5.7 Ω dynamic impedance at 180 mA, 0.125 V voltage regulation (∆VZ), and 100 µA max reverse leakage at 56 V - critical for precision biasing and fault-tolerant voltage clamping.
Technical Context
This Zener diode operates in reverse breakdown with a specified test current IZT of 180 mA and knee current IZK of 250 µA. Its internal metallurgical bond (Category I) ensures robust thermal and mechanical stability under shock, vibration, and rapid thermal cycling.
Designed for DC voltage regulation, it exhibits a positive temperature coefficient of +0.103 %/°C above 7 V and maintains low noise density (≤80 µV/√Hz, 1–3 kHz), making it suitable for low-noise analog references where long-term parametric drift must be minimized.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 75.0 V nominal at 180 mA - defines precise regulation point for feedback loops and clamp thresholds |
| Power Dissipation (PD) | 0.5 W at TEC = 150 °C - sets maximum continuous power handling before thermal derating applies |
| Dynamic Impedance (ZZT) | 1,600 Ω at 180 mA - determines output voltage variation under load transients |
| Voltage Regulation (∆VZ) | 3.40 V - measured change between 10% and 50% of IZM at 25 °C, indicating regulation linearity |
| Max Reverse Leakage (IR1) | 10 µA at 56 V - ensures minimal standby current in high-impedance bias networks |
| Junction Temp Range | -65 °C to +175 °C - enables operation in extreme environments including space-grade and engine-bay electronics |
| Thermal Resistance (RθJEC) | 21 °C/W - junction-to-end-cap path optimized for conduction cooling via PCB copper pads |
Pinout & Package
Package: B-SQ MELF (glass cylindrical surface-mount) with copper end caps, tin/lead or RoHS-compliant matte tin finish; cathode indicated by band; weight 0.0945 g; dimensions BD = 0.070–0.085 in (1.78–2.16 mm), BL = 0.165–0.195 in (4.19–4.95 mm).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / low-side reference node | Connected to ground or lower-potential rail during Zener operation; carries full regulator current in reverse bias |
| Cathode | Zener breakdown terminal / regulated output node | Banded end; supplies stable 75 V reference when reverse-biased above VZ; requires current-limiting resistor |
Key Features
| Feature | Design Value |
|---|---|
| Hermetic voidless glass seal | Prevents moisture ingress and parameter drift over 20+ year deployments in sealed modules |
| Category I metallurgical bond | Enables survivability under MIL-STD-883 mechanical shock (1,500 g) and thermal cycling (-65/+175 °C) |
| MIL-PRF-19500/533 qualification | Validated reliability levels (JAN, JANTXV) with lot traceability and screening per military standards |
| Radiation hardness | Inherently tolerant to total ionizing dose (TID) per MicroNote 050 - no additional shielding required |
| ESD immunity | Non-sensitive per MIL-STD-750 Method 1020 - withstands >4 kV HBM without parameter shift |
Applications
| Aerospace Power Conditioning | Defense System Voltage Reference |
|---|---|
Use Scenario: Regulating auxiliary 75 V bus in satellite power distribution units with wide thermal swing. IC Role / Device Role / Timing Role: Zener diode providing primary voltage reference for DC-DC converter feedback and overvoltage latch. Use Value: Maintains ±0.5% regulation accuracy over -55°C to +125°C ambient due to tight thermal resistance (21 °C/W) and low ∆VZ (3.4 V). |
Use Scenario: Clamping radar transmitter bias rails against ESD-induced transients in ground-based EW systems. IC Role / Device Role / Timing Role: High-reliability transient suppressor protecting GaN amplifier gate drivers. Use Value: Withstands 56 V working peak voltage and 100 µA leakage at 150 °C - prevents false triggering during sustained high-temp operation. |
| Nuclear Instrumentation Biasing | Downhole Oilfield Sensor Supply |
Use Scenario: Generating stable bias for radiation detector preamplifiers in reactor monitoring equipment. IC Role / Device Role / Timing Role: Low-noise Zener reference (≤80 µV/√Hz) establishing baseline for pulse-height analysis. Use Value: Inherent radiation hardness eliminates need for derating or shielding - validated per MicroNote 050 for >100 krad(Si) TID. |
Use Scenario: Providing regulated excitation voltage for piezoresistive pressure sensors in 175 °C downhole tools. IC Role / Device Role / Timing Role: High-temperature-stable voltage reference enabling accurate sensor calibration across full wellbore range. Use Value: Operates continuously at +175 °C junction temperature with no parameter degradation - supported by -65 °C to +175 °C storage rating. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N6345US | Same die, identical electrical specs, but supplied in bulk (not tape-and-reel); no TR suffix | Preferred for manual prototyping or low-volume hand-soldered assemblies | Select 1N6345US/TR for automated SMT placement; choose 1N6345US for bench evaluation or repair kits |
| SMZ75AG | Surface-mount Zener with 75 V, ±5%, 0.5 W, but plastic DO-213AA package; not hermetic or MIL-qualified | Suitable for commercial industrial controls, not aerospace/defense | Use SMZ75AG only where cost and RoHS compliance outweigh reliability and radiation requirements |
Compared with 1N6345US/TR, the 1N6345US offers identical performance without tape-and-reel packaging, while SMZ75AG trades hermeticity and military qualification for lower cost and lead-free compatibility - making the 1N6345US/TR the sole choice for mission-critical, high-temperature, radiation-exposed applications.
Availability
1N6345US/TR is available at Aetrix Electronics and suitable for aerospace power conditioning, defense system voltage reference, nuclear instrumentation biasing, and downhole oilfield sensor supply requiring stable component supply across extended temperature and radiation environments.
Supply support for 1N6345US/TR 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 Corporation (now part of Microchip Technology) designs high-reliability analog and mixed-signal semiconductors for aerospace, defense, and industrial markets, with emphasis on radiation-hardened and extended-temperature solutions.
The 1N6345US/TR belongs to Microsemi's legacy MIL-PRF-19500/533-qualified Zener series, engineered specifically for voltage regulation in safety-critical systems where failure is not an option.
FAQ
What is the Zener voltage tolerance of the 1N6345US/TR?
The 1N6345US/TR has a nominal Zener voltage of 75.0 V with a standard tolerance of ±5%, as confirmed in the Electrical Characteristics table on page 3 of T4-LDS-0193-1 Rev. 1. Tighter tolerances (±1% or ±2%) are available under different part number suffixes (e.g., D or C), but the TR-suffixed version uses the standard 5% tolerance.
Is the 1N6345US/TR qualified to MIL-PRF-19500/533?
Yes, the 1N6345US/TR is explicitly qualified per MIL-PRF-19500/533, supporting JAN, JANTX, JANTXV, and JANS reliability levels. This qualification is documented in the DESCRIPTION section on page 1 and verified through full military screening including temperature cycling, burn-in, and parameter testing.
What is the maximum steady-state power dissipation for the 1N6345US/TR?
The 1N6345US/TR has a steady-state power dissipation (PD) of 0.5 W at an end-cap temperature (TEC) of 150 °C, as specified in the Maximum Ratings table. Derating is required above this temperature per Figure 2 (RθJEC = 21 °C/W), reaching zero power at 255 °C junction temperature.
Does the 1N6345US/TR have radiation hardness certification?
Yes, the 1N6345US/TR is inherently radiation-hardened as described in Microsemi MicroNote 050. Its voidless hermetic glass construction and Category I metallurgical bond provide proven tolerance to total ionizing dose (TID), eliminating the need for external shielding in space or nuclear environments.
What package type does the 1N6345US/TR use?
The 1N6345US/TR uses the B-SQ MELF (Metal Electrode Leadless Face) surface-mount package - a voidless hermetically sealed glass cylinder with copper end caps and cathode band marking. Dimensions are BD = 0.070–0.085 in and BL = 0.165–0.195 in, per Package Dimensions on page 6.
1N6345US/TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- SQ-MELF, B
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 75 V
- Tolerance:
- ±5%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 180 Ohms
- Current - Reverse Leakage @ Vr:
- 50 nA @ 56 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.4 V @ 1 A
- Operating Temperature:
- -65°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- B, SQ-MELF
1N6345US/TR FAQ
1.How can I place an order for 1N6345US/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N6345US/TR 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 1N6345US/TR reliable?
The price and inventory of 1N6345US/TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N6345US/TR is usually 5 days.
3.What payment methods are accepted for 1N6345US/TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N6345US/TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N6345US/TR?
1N6345US/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N6345US/TR 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 1N6345US/TR?
For technical support, including 1N6345US/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N6345US/TR requirements.
6.How does Aetrix verify that 1N6345US/TR is sourced from the original manufacturer or authorized distributors?
All 1N6345US/TR 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 1N6345US/TR meets industry standards.
7.What is the process for return or replacement of 1N6345US/TR?
All 1N6345US/TR units undergo pre-shipment inspection (PSI). If there is an issue with 1N6345US/TR, 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 1N6345US/TR part is unused and in its original packaging.
Return procedure for 1N6345US/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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