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Microchip Technology 1N485BUR/TR
- Part No.:
- 1N485BUR/TR
- Manufacturer:
- Microchip Technology
- Category:
- Single Diodes
- Package:
- DO-213AA
- Datasheet:
-
1N485BUR/TR.pdf
- Description:
- SIGNAL OR COMPUTER DIODE
- Quantity:
- Payment:
- Shipping:
Inventory:8,645
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Product details
Overview
1N485BUR/TR from Microsemi is a hermetically sealed glass switching diode with metallurgically bonded double-plug construction, 180 V reverse voltage rating, 200 mA max operating current at 25°C, and 500 mW power dissipation. It serves as a fast-recovery rectifier in high-reliability DC-DC converter snubber circuits and pulse conditioning stages.
For engineers reviewing the 1N485BUR/TR datasheet, 1N485BUR/TR pinout, 1N485BUR/TR application, or 1N485BUR/TR equivalent, key selection criteria include its 180 V VRWM, 1.0 V max forward voltage at 100 mA, 0.025 µA max reverse leakage at 180 V, -65°C to +175°C operating range, and hermetic glass package suitability for aerospace and downhole instrumentation.
Technical Context
The 1N485BUR/TR is a silicon planar epitaxial switching diode fabricated using metallurgical bonding and double-plug construction to ensure low thermal resistance and stable junction behavior under thermal cycling. Its hermetically sealed glass package eliminates moisture ingress and enables operation up to +175°C ambient without parameter drift.
Designed for high-reliability transient suppression and fast turn-off, the 1N485BUR/TR exhibits 1.0 V max VF at 100 mA and 0.025 µA max IR at rated VRWM, supporting stable performance in pulse-width modulated power control and high-frequency clamp circuits where leakage and forward conduction consistency are critical.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 180 V - Maximum continuous reverse working voltage before significant leakage or breakdown |
| IF(max) | 200 mA at 25°C - Absolute maximum DC forward current without derating |
| VF(max) | 1.0 V at 100 mA, 25°C - Ensures low conduction loss in high-efficiency switching paths |
| IR(max) | 0.025 µA at 180 V, 25°C - Enables reliable blocking in high-impedance sample-and-hold or bias networks |
| Surge Current | 2 A (8.3 ms sine) - Supports single-event transient energy absorption in protection circuits |
| Operating Temp | -65°C to +175°C - Validated for extended-range deployment in oilfield sensors and avionics |
| Power Dissipation | 500 mW at 25°C - Sets thermal design boundary for PCB trace width and heatsinking |
Pinout & Package
Hermetically sealed glass DO-35 package with axial leads; cathode identified by blue band on body; lead material is copper-clad steel with tin/lead finish.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward current entry point | Connected to lower-potential side of switching node; requires thermal relief pad for soldering |
| Cathode | Forward current exit / reverse blocking terminal | Banded end; must be routed to higher-potential rail or clamp node; polarity-sensitive in series protection |
Key Features
| Feature | Design Value |
|---|---|
| Hermetic glass seal | Prevents humidity-induced parameter shift and long-term degradation in sealed enclosures |
| Metallurgically bonded junction | Reduces interfacial thermal resistance for improved pulse current handling and reliability |
| Double-plug construction | Enhances mechanical stability of die attach under thermal shock and vibration stress |
| Wide temperature range | Enables use in unheated outdoor electronics and engine-mounted control modules without derating penalties |
Applications
| Downhole Drilling Sensors | Aerospace Power Converters |
|---|---|
Use Scenario: High-temperature sensor signal conditioning circuit exposed to 150°C ambient and thermal cycling in oil/gas wellbores. IC Role / Device Role / Timing Role: Reverse-biased clamping diode protecting op-amp inputs from ESD and transients during probe insertion. Use Value: 0.025 µA max IR at 180 V ensures minimal offset drift over 10-year deployment; hermetic seal prevents electrolyte corrosion. | Use Scenario: Input rectification stage in a radiation-tolerant DC-DC converter powering flight computers. IC Role / Device Role / Timing Role: Fast-recovery switching diode in flyback snubber network absorbing MOSFET turn-off spikes. Use Value: 2 A surge rating and -65°C to +175°C range support MIL-STD-704 compliance and mission-critical uptime. |
| Industrial Motor Drive Gate Protection | Medical Imaging Power Supplies |
Use Scenario: Isolated gate driver output stage in variable-frequency drives operating near induction motors. IC Role / Device Role / Timing Role: Bidirectional transient suppressor across IGBT gate-emitter terminals during switching transitions. Use Value: 1.0 V max VF minimizes forward conduction loss during active clamping; glass package resists outgassing in vacuum-cooled systems. | Use Scenario: High-voltage auxiliary supply rectification in CT scanner X-ray generator modules. IC Role / Device Role / Timing Role: Primary-side rectifier in resonant LLC converter delivering isolated 200 V bias rails. Use Value: 180 V VRWM supports 1.5× safety margin over 120 VAC-derived bus; 500 mW rating allows compact layout without forced air. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar switching diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LL485B | Same die, plastic DO-35 package; no hermetic seal; 175°C max operating temp | Suitable for commercial-grade motor controls but not downhole or aerospace | Select LL485B only when cost sensitivity outweighs long-term reliability and extended temperature needs |
| CDLL485B | Same die, surface-mount SOD-323 package; 1.0 V VF identical; 0.05 µA IR at 180 V | Enables automated assembly and space-constrained PCBs; less robust against mechanical stress | Choose CDLL485B for high-volume consumer electronics where reflow compatibility and footprint reduction are primary |
Compared with LL485B and CDLL485B, the 1N485BUR/TR delivers superior long-term parameter stability via hermetic sealing and wider temperature capability, making it the sole choice for mission-critical environments where field failure is unacceptable.
Availability
1N485BUR/TR is available at Aetrix Electronics and suitable for downhole instrumentation, aerospace power converters, industrial motor drive protection, and medical imaging power supplies requiring stable component supply across extended temperature ranges and long service life.
Supply support for 1N485BUR/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 (now part of Microchip Technology) is a U.S.-based semiconductor company specializing in high-reliability analog and mixed-signal ICs, discrete devices, and radiation-hardened components.
The 1N485BUR/TR belongs to Microsemi's legacy high-temperature switching diode product line, engineered specifically for harsh-environment applications including oilfield, avionics, and medical systems where parameter stability and hermetic integrity are non-negotiable.
FAQ
What is the maximum reverse voltage rating for the 1N485BUR/TR?
The 1N485BUR/TR has a DC reverse working voltage (VRWM) rating of 180 V. This value is specified at 25°C ambient and represents the highest continuous reverse-bias voltage the device can withstand without exceeding the 0.025 µA leakage limit. Operation above this voltage risks irreversible breakdown and must be avoided in all designs using the 1N485BUR/TR.
Does the 1N485BUR/TR have a hermetic package, and why does it matter?
Yes, the 1N485BUR/TR uses a hermetically sealed glass DO-35 package. This construction prevents moisture and atmospheric contaminants from reaching the silicon junction, eliminating parameter drift due to humidity exposure. For the 1N485BUR/TR, this directly enables its guaranteed -65°C to +175°C operating range and long-term reliability in sealed enclosures such as downhole tools and avionics modules.
What is the forward voltage drop of the 1N485BUR/TR at rated current?
The 1N485BUR/TR exhibits a maximum forward voltage (VF) of 1.0 V at 100 mA DC forward current and 25°C ambient temperature. At 200 mA, VF remains within specification but increases slightly; the datasheet does not specify a max VF at 200 mA. This 1.0 V value defines conduction loss boundaries in power path designs using the 1N485BUR/TR.
Can the 1N485BUR/TR replace standard plastic-packaged diodes like 1N4148 in high-temperature circuits?
No - the 1N485BUR/TR is not a direct replacement for 1N4148. While both are switching diodes, the 1N485BUR/TR has higher VRWM (180 V vs. 100 V), higher IF(max) (200 mA vs. 300 mA), and is rated to +175°C versus +150°C for 1N4148. More critically, the 1N485BUR/TR's hermetic glass package and metallurgical bonding make it unsuitable for reflow soldering, unlike plastic SMT diodes. Use the 1N485BUR/TR only where its specific high-temp, high-reliability traits are required.
What is the surge current rating of the 1N485BUR/TR, and how is it defined?
The 1N485BUR/TR has a peak non-repetitive surge current rating of 2 A, defined for a single half-sine wave pulse of 8.3 milliseconds duration at 25°C ambient. This rating reflects the device's ability to absorb transient energy without junction failure and is validated per JEDEC standards. It applies only to infrequent events - repeated surges exceeding this limit will degrade the 1N485BUR/TR's lifetime and must be limited by external circuitry.
1N485BUR/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):
- 180 V
- Current - Average Rectified (Io):
- 200mA
- Voltage - Forward (Vf) (Max) @ If:
- 1 V @ 100 mA
- Speed:
- Small Signal =< 200mA (Io), Any Speed
- Reverse Recovery Time (trr):
- -
- Current - Reverse Leakage @ Vr:
- 100 µA @ 200 V
- Capacitance @ Vr, F:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-213AA
- Operating Temperature - Junction:
- -65°C ~ 175°C
1N485BUR/TR FAQ
1.How can I place an order for 1N485BUR/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N485BUR/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 1N485BUR/TR reliable?
The price and inventory of 1N485BUR/TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N485BUR/TR is usually 5 days.
3.What payment methods are accepted for 1N485BUR/TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N485BUR/TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N485BUR/TR?
1N485BUR/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N485BUR/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 1N485BUR/TR?
For technical support, including 1N485BUR/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N485BUR/TR requirements.
6.How does Aetrix verify that 1N485BUR/TR is sourced from the original manufacturer or authorized distributors?
All 1N485BUR/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 1N485BUR/TR meets industry standards.
7.What is the process for return or replacement of 1N485BUR/TR?
All 1N485BUR/TR units undergo pre-shipment inspection (PSI). If there is an issue with 1N485BUR/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 1N485BUR/TR part is unused and in its original packaging.
Return procedure for 1N485BUR/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N485BUR/TR Tags
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