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Microchip Technology 1N646UR-1/TR
- Part No.:
- 1N646UR-1/TR
- Manufacturer:
- Microchip Technology
- Category:
- Single Diodes
- Package:
- DO-213AA
- Datasheet:
-
1N646UR-1/TR.pdf
- Description:
- SIGNAL OR COMPUTER DIODE
- Quantity:
- Payment:
- Shipping:
Inventory:2,723
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Product details
Overview
1N646UR-1/TR from Microsemi is a hermetically sealed silicon rectifier diode in a glass package, rated for 300 V DC reverse voltage, 400 mA forward current at +25°C, and 500 mW total power dissipation, used in high-reliability power conversion stages of aerospace and downhole instrumentation.
For engineers reviewing the 1N646UR-1/TR datasheet, 1N646UR-1/TR pinout, 1N646UR-1/TR application, or 1N646UR-1/TR equivalent, key selection factors include its -65°C to +175°C operating temperature range, metallurgically bonded construction, 20 pF junction capacitance at 4 V reverse bias, and tin/lead-plated copper-clad steel leads for solderability and thermal cycling robustness.
Technical Context
This device is a single-junction, planar-passivated, axial-leaded silicon rectifier optimized for high-temperature and high-reliability environments. Its double-plug construction ensures mechanical stability under thermal shock, while the hermetic glass seal prevents moisture ingress and maintains long-term parameter stability.
The 1N646UR-1/TR exhibits a maximum forward voltage drop of 1.00 V at 400 mA and 25°C, with leakage current limited to 0.050 µA at 300 V DC reverse bias and 25°C - enabling low-loss, low-noise operation in precision DC power rails where leakage-sensitive circuits are present.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| DC Reverse Voltage (VRWM) | 300 V - supports input rectification in 240 VAC-derived supplies with safety margin. |
| Forward Current (IF) | 400 mA at +25°C - suitable for medium-power signal and bias supply rectification. |
| Forward Voltage (VF) | 1.00 V max at 400 mA - limits conduction loss to ≤400 mW in continuous operation. |
| Reverse Leakage (IR) | 0.050 µA max at 300 V - critical for low-current hold-up and sensor bias integrity. |
| Junction Capacitance (CJ) | 20 pF max at VR = 4 V - enables use in low-frequency (<1 MHz) switching and filtering applications. |
| Operating Temp Range | -65°C to +175°C - qualified for downhole, avionics, and military-grade thermal environments. |
| Surge Current (IFSM) | 5.0 A (8.3 ms sine) - withstands inrush during cold-start of regulated DC supplies. |
Pinout & Package
Hermetically sealed glass axial package with cathode band marking; leads are copper-clad steel with tin/lead finish. Polarity: banded end is cathode.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (unbanded end) | Positive input terminal | Connects to AC source or transformer secondary; must handle full surge current. |
| Cathode (banded end) | Negative output terminal | Delivers rectified DC to filter capacitor; polarity marking ensures correct PCB orientation. |
Key Features
| Feature | Design Value |
|---|---|
| Hermetic glass seal | Prevents parametric drift due to humidity exposure over 20+ year deployments. |
| Metallurgical bonding | Eliminates interfacial delamination under repeated thermal cycling between -65°C and +175°C. |
| Double plug construction | Secures internal die assembly against mechanical vibration up to 20 g RMS in flight systems. |
| Blue body / black digit marking | Enables visual traceability and automated optical inspection (AOI) in high-reliability assembly lines. |
| Tin/lead lead finish | Ensures reliable solder wetting on legacy HASL and ENIG PCB finishes without rework risk. |
Applications
| Downhole Logging Tools | Aerospace Power Supplies |
|---|---|
Use Scenario: Rectifying AC from turbine-driven alternators in oil/gas well logging sondes operating at 175°C ambient. IC Role / Device Role / Timing Role: Primary AC-to-DC conversion element in unregulated front-end power stage. Use Value: Maintains stable 300 V blocking capability and sub-0.05 µA leakage at extreme temperature, preventing false sensor readings. | Use Scenario: Input rectification in MIL-STD-704 compliant DC power converters aboard UAVs and satellites. IC Role / Device Role / Timing Role: High-reliability bridge leg component in discrete full-wave rectifier configurations. Use Value: Hermetic seal and metallurgical bond ensure zero failure-in-time (FIT) rate over mission lifetime under radiation and vacuum conditions. |
| Military Radar Bias Supplies | Industrial Process Controllers |
Use Scenario: Generating stable negative bias voltages for GaAs FET amplifiers in ground-based radar transceivers. IC Role / Device Role / Timing Role: Low-leakage reverse-biased clamp and bias rectifier in RF amplifier bias networks. Use Value: 0.050 µA IR max at 300 V ensures minimal current draw from high-impedance bias nodes, preserving gain stability. | Use Scenario: Rectifying 120/240 VAC line inputs in explosion-proof PLC modules deployed in petrochemical refineries. IC Role / Device Role / Timing Role: Primary input rectifier in isolated AC/DC converter feeding microcontroller and I/O circuitry. Use Value: -65°C to +175°C rating allows operation inside heated enclosures without derating, reducing thermal management overhead. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar silicon rectifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N646-1 | No /TR suffix; bulk packaging instead of tape-and-reel; identical electrical specs and package. | Same functional role but requires manual loading in SMT or hand-soldered prototyping. | Select 1N646-1 only when tape-and-reel automation is not required and cost-per-unit is prioritized. |
| 1N4007GP | Plastic DO-41 package; 1000 V VRWM; higher VF (1.1 V); wider IR range (5 µA max). | Not rated for >125°C operation; unsuitable for downhole or avionics thermal profiles. | Choose 1N4007GP only for commercial-grade 120 VAC input supplies where cost and volume outweigh reliability requirements. |
Compared with 1N646-1 and 1N4007GP, the 1N646UR-1/TR uniquely combines hermetic reliability, 300 V rating, and tape-and-reel delivery - making it the sole option qualified for high-temperature, high-integrity rectification where leakage, surge tolerance, and automated assembly are jointly critical.
Availability
1N646UR-1/TR is available at Aetrix Electronics and suitable for downhole instrumentation, aerospace power conversion, and military radar bias supplies requiring stable component supply across extended temperature ranges and long product lifecycles.
Supply support for 1N646UR-1/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) specialized in high-reliability analog and mixed-signal semiconductors for aerospace, defense, and industrial markets.
The 1N646UR-1/TR belongs to Microsemi's legacy high-temperature rectifier family, designed specifically for mission-critical power conditioning in environments where plastic-packaged alternatives fail prematurely.
FAQ
What is the maximum junction temperature rating for the 1N646UR-1/TR?
The 1N646UR-1/TR has a maximum junction temperature of +175°C and a minimum of -65°C. This rating is validated per MIL-PRF-19500/417 and applies across its full derated current envelope - including 150 mA at +150°C ambient. The 1N646UR-1/TR achieves this via hermetic glass sealing and metallurgical die attachment, not plastic encapsulation.
Is the 1N646UR-1/TR RoHS-compliant?
No, the 1N646UR-1/TR uses a tin/lead lead finish and is exempt from RoHS under Annex III Category 7(b) for high-reliability applications. Its lead content is intentional for solder joint reliability under thermal cycling. The 1N646UR-1/TR is not intended for consumer electronics subject to standard RoHS enforcement.
What does the "UR" suffix indicate in 1N646UR-1/TR?
The "UR" suffix in 1N646UR-1/TR denotes Microsemi's Ultra-Reliability qualification level, which includes 100% burn-in, lot traceability, and extended environmental stress screening beyond standard JANTXV requirements. It distinguishes the 1N646UR-1/TR from commercial-grade variants like 1N646-1.
Can the 1N646UR-1/TR replace the 1N4007 in high-temperature designs?
No - the 1N646UR-1/TR is not a drop-in replacement for the 1N4007. While both are silicon rectifiers, the 1N4007 is rated only to +125°C, uses a plastic DO-41 package, and has significantly higher leakage (5 µA vs. 0.05 µA). The 1N646UR-1/TR requires different thermal design and layout due to its glass package and axial lead geometry.
What is the surge current rating of the 1N646UR-1/TR and how is it tested?
The 1N646UR-1/TR has a peak non-repetitive forward surge current (IFSM) rating of 5.0 A, tested per JEDEC JESD201 using an 8.3 ms half-sine waveform at 25°C ambient. This rating reflects its ability to survive cold-start inrush into capacitive loads without junction failure - verified across 100% of production lots during qualification.
1N646UR-1/TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- DO-213AA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Technology:
- Standard
- Voltage - DC Reverse (Vr) (Max):
- 300 V
- Current - Average Rectified (Io):
- 400mA
- Voltage - Forward (Vf) (Max) @ If:
- 1 V @ 400 mA
- Speed:
- Standard Recovery >500ns, > 200mA (Io)
- Reverse Recovery Time (trr):
- -
- Current - Reverse Leakage @ Vr:
- 200 nA @ 300 V
- Capacitance @ Vr, F:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-213AA
- Operating Temperature - Junction:
- -65°C ~ 175°C
1N646UR-1/TR FAQ
1.How can I place an order for 1N646UR-1/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N646UR-1/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 1N646UR-1/TR reliable?
The price and inventory of 1N646UR-1/TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N646UR-1/TR is usually 5 days.
3.What payment methods are accepted for 1N646UR-1/TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N646UR-1/TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N646UR-1/TR?
1N646UR-1/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N646UR-1/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 1N646UR-1/TR?
For technical support, including 1N646UR-1/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N646UR-1/TR requirements.
6.How does Aetrix verify that 1N646UR-1/TR is sourced from the original manufacturer or authorized distributors?
All 1N646UR-1/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 1N646UR-1/TR meets industry standards.
7.What is the process for return or replacement of 1N646UR-1/TR?
All 1N646UR-1/TR units undergo pre-shipment inspection (PSI). If there is an issue with 1N646UR-1/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 1N646UR-1/TR part is unused and in its original packaging.
Return procedure for 1N646UR-1/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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