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Microchip Technology 1N6639US
- Part No.:
- 1N6639US
- Manufacturer:
- Microchip Technology
- Category:
- Single Diodes
- Package:
- SQ-MELF, D
- Datasheet:
-
1N6639US.pdf
- Description:
- DIODE GEN PURPOSE
- Quantity:
- Payment:
- Shipping:
Inventory:6,980
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Product details
Overview
1N6639US from Microsemi is a hermetically sealed, metallurgically bonded, non-cavity glass switching diode rated for 75 V reverse working voltage (VRWM), 100 V peak reverse voltage (VBRR), and 300 mA operating current, with forward voltage of 0.62 V at 500 mA pulsed, used in high-reliability timing, pulse shaping, and clamping circuits in aerospace and defense systems.
For engineers reviewing the 1N6639US datasheet, 1N6639US pinout, 1N6639US application, or 1N6639US equivalent, key selection criteria include its MIL-PRF-19500/609 qualification, -65°C to +175°C operating temperature range, 4.0 ns reverse recovery time (tRR), 2.5 pF junction capacitance (CT), and axial D-5D package with tin/lead leads.
Technical Context
This diode operates as a fast-switching unidirectional rectifier with defined turn-on threshold and controlled minority-carrier lifetime. Its 4.0 ns tRR and 2.5 pF CT support sub-microsecond signal edge fidelity in pulse generation and waveform clipping circuits.
Rated for 75 V VRWM and 100 V VBRR under MIL-PRF-19500/609, it sustains 100 nA reverse leakage at 10 µA test current and exhibits thermal resistance of 50 °C/W (ROJEC) at L = 0, enabling stable operation across military-grade temperature extremes.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 75 V - maximum continuous reverse voltage before significant leakage or breakdown |
| VBRR | 100 V - peak reverse voltage the device withstands without avalanche conduction |
| tRR | 4.0 ns - time required to transition from conduction to blocking state, critical for high-speed switching |
| CT | 2.5 pF - junction capacitance at zero bias, directly limiting high-frequency signal coupling and bandwidth |
| IF (pulsed) | 500 mA - peak forward current capability in short-duration pulses, supporting transient load handling |
| VF @ 500 mA | 0.62 V - forward voltage drop defining conduction loss and self-heating under rated pulsed load |
| Operating Temp | -65°C to +175°C - full military temperature range compliance per MIL-PRF-19500/609 |
Pinout & Package
Package: Hermetically sealed axial D-5D glass case per MIL-PRF-19500/609; cathode identified by band; lead finish: tin/lead; thermal resistance ROJEC = 50 °C/W max at L = 0.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward current entry point | Connects to lower-potential side of circuit; must be biased positive relative to cathode for conduction |
| Cathode | Forward current exit point | Banded end; connects to higher-potential side during forward bias; defines polarity-sensitive placement |
Key Features
| Feature | Design Value |
|---|---|
| MIL-PRF-19500/609 Qualified | Fully compliant with military specification for switching diodes, including screening, testing, and traceability requirements |
| Hermetic D-5D Glass Package | Provides long-term reliability and moisture resistance in harsh environments, eliminating cavity-related failure modes |
| 4.0 ns Reverse Recovery Time | Enables clean switching in >100 MHz pulse applications without tail current or ringing artifacts |
| -65°C to +175°C Operating Range | Supports deployment in engine bays, avionics bays, and space-constrained military electronics without derating below 110°C |
| Metallurgical Bond Construction | Ensures low contact resistance and stable interfacial behavior over thermal cycling and vibration stress |
Applications
| Radar Pulse Clamping | Missile Guidance Timing |
|---|---|
Use Scenario: Clamping RF receiver front-end inputs to protect sensitive mixers from high-voltage radar transmit pulses. IC Role / Device Role / Timing Role: Fast-switching diode acting as voltage limiter with sub-5 ns recovery to preserve pulse integrity. Use Value: Prevents damage while maintaining <2.5 pF signal path capacitance to avoid degrading GHz-bandwidth response. | Use Scenario: Generating precise trigger edges for inertial measurement unit (IMU) sampling clocks in tactical missiles. IC Role / Device Role / Timing Role: Edge-shaping diode in Schmitt-trigger-based oscillator circuits requiring nanosecond repeatability. Use Value: Delivers consistent 4.0 ns tRR across -65°C to +175°C, ensuring timing jitter remains <100 ps over full mission profile. |
| Satellite Power Sequencing | Avionics Signal Isolation |
Use Scenario: Controlling power-up sequencing between redundant flight computer modules in LEO satellites. IC Role / Device Role / Timing Role: High-reliability isolation diode in OR-ing and enable-path circuits with zero standby leakage. Use Value: Maintains <100 nA IR at 10 µA test condition and survives 2.5 A surge events per MIL-STD-750 Method 2070. | Use Scenario: Isolating analog sensor outputs from shared data bus lines in fly-by-wire control computers. IC Role / Device Role / Timing Role: Bidirectional transient suppressor and DC blocking element in protected I/O paths. Use Value: Combines 75 V VRWM hold-off with 100 V VBRR surge margin and <2.5 pF CT to prevent signal distortion up to 500 MHz. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar switching diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N6640US | Lower VRWM (50 V), higher VF (0.86 V @ 50 mA), same tRR (4.0 ns) and CT (2.5 pF) | Optimized for lower-voltage logic-level clamping; unsuitable for 75 V hold-off requirements | Select only when system VRWM ≤ 50 V and forward loss budget allows ≥0.86 V drop |
| 1N6641US | Same VRWM (50 V), higher tRR (5.0 ns), higher CT (3.0 pF), identical temperature rating | Trade-off of speed for improved surge robustness; not interchangeable where <4.5 ns tRR is mandatory | Prefer only in applications tolerant of 1 ns slower recovery and 0.5 pF higher capacitance |
Compared with 1N6639US, 1N6640US offers lower voltage rating but identical speed, while 1N6641US sacrifices 1 ns in tRR and adds 0.5 pF CT for enhanced ruggedness-neither is pin-compatible nor drop-in; all three require separate layout validation per voltage, speed, and capacitance constraints.
Availability
1N6639US is available at Aetrix Electronics and suitable for radar pulse clamping, missile guidance timing, and satellite power sequencing requiring stable component supply under extended temperature and radiation-hardened conditions.
Supply support for 1N6639US 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) designs high-reliability analog and mixed-signal semiconductors for aerospace, defense, and industrial markets, emphasizing radiation tolerance and extended temperature performance.
The 1N6639US belongs to Microsemi's MIL-PRF-19500/609 qualified switching diode family, engineered specifically for high-speed, high-stability signal conditioning in mission-critical electronic systems.
FAQ
What is the maximum reverse working voltage (VRWM) for the 1N6639US?
The 1N6639US has a VRWM of 75 V, meaning it can continuously block up to 75 V in reverse bias without exceeding specified leakage current limits. This rating is verified per MIL-PRF-19500/609 and applies across the full -65°C to +175°C operating temperature range. Exceeding 75 V risks increased reverse leakage or premature breakdown, especially at elevated temperatures.
Does the 1N6639US have a specified reverse recovery time (tRR)?
Yes, the 1N6639US has a guaranteed maximum reverse recovery time of 4.0 ns at IF = 10 mA and VR = 0 V, measured with RL = 100 Ω. This value is critical for high-speed switching applications such as pulse shaping and RF clamping, where faster recovery minimizes switching losses and preserves signal edge integrity in systems operating above 50 MHz.
What package type does the 1N6639US use, and how is polarity marked?
The 1N6639US uses the hermetically sealed axial D-5D glass package per MIL-PRF-19500/609, with cathode polarity indicated by a visible band on the glass body. The leads are tin/lead plated, and the device features a coefficient of expansion matched to standard PCB materials. Mechanical dimensions are tightly controlled: D = 1.78–2.16 mm, G = 4.19–4.95 mm.
Is the 1N6639US suitable for use beyond 125°C ambient temperature?
Yes, the 1N6639US is fully rated for operation from -65°C to +175°C junction temperature, with no derating required until TEC exceeds +110°C. Above that point, current must be reduced by 4.6 mA/°C. Its 50 °C/W thermal resistance (ROJEC) and metallurgical bond construction ensure reliable performance in engine-mounted or space-constrained high-temp environments where commercial diodes fail.
How does the 1N6639US compare to the 1N6640US in forward voltage performance?
The 1N6639US has a forward voltage of 0.62 V at 500 mA pulsed, whereas the 1N6640US specifies 0.86 V at only 50 mA DC. This reflects different optimization points: 1N6639US targets high-current pulse fidelity, while 1N6640US prioritizes low-leakage stability at modest currents. Direct substitution is invalid due to mismatched VF, VRWM, and current ratings.
1N6639US Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- SQ-MELF, D
- Packaging:
- Bulk
- Product Status:
- Active
- Technology:
- Standard
- Voltage - DC Reverse (Vr) (Max):
- 75 V
- Current - Average Rectified (Io):
- 300mA
- Voltage - Forward (Vf) (Max) @ If:
- 1.2 V @ 500 mA
- Speed:
- Fast Recovery =< 500ns, > 200mA (Io)
- Reverse Recovery Time (trr):
- 4 ns
- Current - Reverse Leakage @ Vr:
- 100 nA @ 75 V
- Capacitance @ Vr, F:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- D-5D
- Operating Temperature - Junction:
- -65°C ~ 175°C
1N6639US FAQ
1.How can I place an order for 1N6639US through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N6639US 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 1N6639US reliable?
The price and inventory of 1N6639US are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N6639US is usually 5 days.
3.What payment methods are accepted for 1N6639US?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N6639US transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N6639US?
1N6639US orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N6639US 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 1N6639US?
For technical support, including 1N6639US datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N6639US requirements.
6.How does Aetrix verify that 1N6639US is sourced from the original manufacturer or authorized distributors?
All 1N6639US 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 1N6639US meets industry standards.
7.What is the process for return or replacement of 1N6639US?
All 1N6639US units undergo pre-shipment inspection (PSI). If there is an issue with 1N6639US, 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 1N6639US part is unused and in its original packaging.
Return procedure for 1N6639US:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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