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Microchip Technology 1N4449/TR
- Part No.:
- 1N4449/TR
- Manufacturer:
- Microchip Technology
- Category:
- Single Diodes
- Package:
- DO-204AH, DO-35, Axial
- Datasheet:
-
1N4449/TR.pdf
- Description:
- DIODE GEN PURP 75V 200MA DO35
- Quantity:
- Payment:
- Shipping:
Inventory:8,793
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Product details
Overview
1N4449/TR from Microsemi is a hermetically sealed, metallurgically bonded silicon switching diode in DO-35 (DO-204AH) package, rated for 75 V peak reverse voltage, 200 mA average forward current, 4 ns reverse recovery time, and 2 pF junction capacitance at 0 V. It serves as a high-speed signal rectifier in data line interface circuits.
For engineers reviewing the 1N4449/TR datasheet, 1N4449/TR pinout, 1N4449/TR application, or 1N4449/TR equivalent, key selection criteria include reverse recovery time, junction capacitance, peak reverse voltage, forward voltage drop at 30 mA, and MIL-PRF-19500 screening compatibility.
Technical Context
This diode uses internal metallurgical bonding to achieve stable low-leakage performance across temperature. Its double-plug DO-35 glass package ensures hermetic sealing and mechanical robustness for high-reliability through-hole mounting.
The 1N4449/TR exhibits 2 pF junction capacitance at 0 V and 4 ns reverse recovery time under 10 mA test conditions - parameters critical for minimizing signal distortion in RS-232/RS-422 and Ethernet 10 Base-T data line applications.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Reverse Voltage (VRWM) | 75 V - supports operation in 5 V–24 V logic-level signal paths with margin against transients. |
| Reverse Recovery Time (trr) | 4 ns - enables reliable switching up to ~100 MHz in digital signal routing and pulse shaping. |
| Junction Capacitance (CJ) | 2 pF @ 0 V - minimizes capacitive loading on high-speed data lines such as RS-232 receivers. |
| Forward Voltage (VF) | 1.0 V @ 30 mA - ensures low power dissipation and minimal voltage drop in series-coupled signal conditioning. |
| Average Forward Current (IO) | 200 mA - sufficient for transient clamping and level-shifting in peripheral interface circuits. |
| Operating Junction Temp | –65 °C to +150 °C - validated for industrial and extended-temperature embedded systems. |
Pinout & Package
1N4449/TR is housed in a hermetically sealed DO-35 (DO-204AH) glass package with axial leads. Cathode is marked by a visible band on the glass body; polarity must be observed during PCB placement.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward current entry point | Connected to lower-potential side of signal path; accepts forward bias for conduction. |
| Cathode | Forward current exit / reverse blocking terminal | Marked by colored band; connected to higher-potential side or ground reference in clamping configurations. |
Key Features
| Feature | Design Value |
|---|---|
| Hermetic glass seal | Prevents moisture ingress and long-term parameter drift in humid or harsh environments. |
| Metallurgical bonding | Ensures low thermal resistance and stable junction characteristics over 1000+ thermal cycles. |
| Double-plug construction | Improves mechanical lead retention and solder joint reliability during board flex or vibration stress. |
| MIL-PRF-19500 screening option | Enables use in defense/aerospace programs requiring tested lot traceability and burn-in validation. |
Applications
| RS-232 Interface Protection | Ethernet 10 Base-T Signal Clamping |
|---|---|
Use Scenario: Protecting UART transceivers from ESD and line reflections in industrial serial links. IC Role / Device Role / Timing Role: Signal-level clamping diode placed between TX/RX lines and ground or VCC rail. Use Value: 2 pF capacitance avoids signal edge degradation; 4 ns trr prevents data corruption at 115.2 kbps baud rates. | Use Scenario: Limiting differential voltage swing on twisted-pair PHY interfaces to prevent receiver saturation. IC Role / Device Role / Timing Role: Bidirectional transient suppressor in MDI/MDI-X signal paths. Use Value: 75 V VRWM accommodates common-mode surges; low leakage (<20 nA @ 75 V) maintains DC bias integrity. |
| Plated-Wire Memory Drivers | Thin-Film Memory Sense Circuits |
Use Scenario: Driving fast current pulses into plated-wire memory cores for read/write operations. IC Role / Device Role / Timing Role: High-speed flyback path for magnetic core reset current. Use Value: 4 ns trr allows clean current reversal within sub-100 ns timing windows required for core switching. | Use Scenario: Amplifying small voltage differentials from thin-film memory cells during sense amplification. IC Role / Device Role / Timing Role: Low-capacitance signal path isolation diode in front-end analog chain. Use Value: 2 pF CJ avoids loading sensitive sense nodes; <20 nA IR preserves microvolt-level signal fidelity. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar switching diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4448-1 | Same VRWM (75 V), same trr (4 ns), but 4 pF CJ vs. 2 pF for 1N4449/TR. | Suitable where 2 pF advantage is non-critical; less effective in >20 MHz signal paths. | Select 1N4448-1 only if cost sensitivity outweighs capacitance-driven signal integrity requirements. |
| BAS16-TR | Lower VRWM (80 V), faster trr (4 ns typ.), 1.5 pF CJ, SOT-23 package - surface-mount only. | Requires PCB redesign; not drop-in compatible due to package and lead form factor. | Choose BAS16-TR for space-constrained designs needing improved high-frequency response, accepting re-layout effort. |
Compared with 1N4448-1 and BAS16-TR, the 1N4449/TR uniquely balances ultra-low 2 pF capacitance, through-hole DO-35 reliability, and MIL-PRF-19500 screening readiness - making it optimal for legacy industrial and defense data interface upgrades where layout change is prohibited.
Availability
1N4449/TR is available at Aetrix Electronics and suitable for RS-232 interface protection, Ethernet 10 Base-T clamping, and plated-wire memory driver applications requiring stable component supply across extended product lifecycles.
Supply support for 1N4449/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) is a U.S.-based semiconductor company specializing in high-reliability analog and mixed-signal components for aerospace, defense, and industrial markets.
The 1N4449/TR belongs to Microsemi's legacy JEDEC-registered switching diode family, designed specifically for high-speed signal integrity in military-grade and industrial computing interfaces.
FAQ
What is the maximum reverse recovery time specified for the 1N4449/TR?
The 1N4449/TR has a reverse recovery time (trr) of 4 ns when tested at 10 mA. This value is measured under standardized conditions per JESD282-B and reflects its capability to switch rapidly in high-frequency signal paths without introducing timing skew or overshoot. The 4 ns trr makes the 1N4449/TR suitable for applications up to approximately 100 MHz, including RS-232 and Ethernet 10 Base-T interfaces.
Does the 1N4449/TR meet RoHS compliance requirements?
Yes, the 1N4449/TR is available in RoHS-compliant versions marked with the "e3" suffix per part nomenclature. These variants use matte-tin over copper-clad steel leads and conform to EU Directive 2011/65/EU. Non-RoHS versions (blank suffix) remain available for legacy or high-reliability programs requiring tin-lead plating per MIL-STD-750.
What is the junction capacitance of the 1N4449/TR and why does it matter?
The 1N4449/TR exhibits 2 pF junction capacitance at 0 V reverse bias - the lowest in its 1N4446–1N4449 series. This ultra-low capacitance minimizes signal loading on high-speed data lines, preserving edge rate and reducing crosstalk in applications like RS-232 receivers and Ethernet PHY interfaces. Lower CJ directly improves bandwidth and noise immunity in fast-switching signal paths.
Can the 1N4449/TR be used in place of the 1N4148 diode?
The 1N4449/TR shares identical electrical ratings (75 V VRWM, 4 ns trr, 200 mA IO) with the 1N4148 but offers lower junction capacitance (2 pF vs. 4 pF). While functionally interchangeable in many circuits, the 1N4449/TR provides superior high-frequency performance. However, substitution requires verification of mechanical fit - both use DO-35, but marking and screening options differ.
Is MIL-PRF-19500 screening available for the 1N4449/TR?
Yes, MIL-PRF-19500 screening is available for the 1N4449/TR via specific part number variants (e.g., MQ/ MX/ MV prefixes). Screening includes temperature cycling, steady-state life test, and lot traceability per Class H or K requirements. This makes the 1N4449/TR suitable for aerospace and defense applications where reliability validation is mandatory.
1N4449/TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- DO-204AH, DO-35, Axial
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Technology:
- Standard
- Voltage - DC Reverse (Vr) (Max):
- 75 V
- Current - Average Rectified (Io):
- 200mA
- Voltage - Forward (Vf) (Max) @ If:
- 1 V @ 30 mA
- Speed:
- Small Signal =< 200mA (Io), Any Speed
- Reverse Recovery Time (trr):
- 4 ns
- Current - Reverse Leakage @ Vr:
- 25 nA @ 20 V
- Capacitance @ Vr, F:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-204AH (DO-35)
- Operating Temperature - Junction:
- -65°C ~ 150°C
1N4449/TR FAQ
1.How can I place an order for 1N4449/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4449/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 1N4449/TR reliable?
The price and inventory of 1N4449/TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4449/TR is usually 5 days.
3.What payment methods are accepted for 1N4449/TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4449/TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4449/TR?
1N4449/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4449/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 1N4449/TR?
For technical support, including 1N4449/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4449/TR requirements.
6.How does Aetrix verify that 1N4449/TR is sourced from the original manufacturer or authorized distributors?
All 1N4449/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 1N4449/TR meets industry standards.
7.What is the process for return or replacement of 1N4449/TR?
All 1N4449/TR units undergo pre-shipment inspection (PSI). If there is an issue with 1N4449/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 1N4449/TR part is unused and in its original packaging.
Return procedure for 1N4449/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N4449/TR Tags
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