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Microchip Technology 1N6634US/TR
- Part No.:
- 1N6634US/TR
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- SQ-MELF, E
- Datasheet:
-
1N6634US/TR.pdf
- Description:
- DIODE ZENER 3.9V 5W E-MELF
- Quantity:
- Payment:
- Shipping:
Inventory:100
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Product details
Overview
1N6634US/TR from Microsemi is a surface-mount, voidless-hermetically-sealed glass Zener diode rated for 5 W power dissipation at TEC = 125 °C, with nominal Zener voltage of 3.9 V ±5%, dynamic impedance of 2.0 Ω at 320 mA test current, and operating junction temperature range from –65 °C to +175 °C. It serves as a precision voltage reference or shunt regulator in high-reliability aerospace, defense, and downhole instrumentation circuits.
For engineers reviewing the 1N6634US/TR datasheet, 1N6634US/TR pinout, 1N6634US/TR application, or 1N6634US/TR equivalent, key selection criteria include its Category III metallurgical bond construction, 10 °C/W junction-to-end-cap thermal resistance, radiation-hardened behavior per MicroNote 050, and compatibility with EIA-481-B tape-and-reel packaging for automated SMT assembly.
Technical Context
This device operates in reverse-bias breakdown mode with a well-defined Zener knee at IZK = 1 mA (VZK = 0.75 V), delivering stable regulation across 10%–50% of IZM (1220 mA) with ΔVZ ≤ 1.0 V. Its triple-layer passivation and tungsten-slug hermetic glass package ensure immunity to moisture ingress and long-term parametric stability under thermal cycling.
The 1N6634US/TR exhibits a negative temperature coefficient of –0.060 %/°C at IZT, low forward voltage (1.50 V @ 1.0 A), and surge capability of 17.6 A for 8.3 ms square-wave pulses. It complies with MIL-PRF-19500/356 for JAN/JANTXV screening levels and meets MIL-STD-750 Method 1020 for ESD robustness.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage VZ | 3.9 V ±5% at IZT = 320 mA - defines nominal regulation point under standard test conditions |
| Power Dissipation | 5 W @ TEC = 125 °C - maximum continuous power handling before thermal derating begins |
| Dynamic Impedance ZZ | 2.0 Ω @ IZT - low AC impedance ensures minimal output voltage variation under load transients |
| Junction Temperature Range | –65 °C to +175 °C - enables operation in extreme environments including oilfield and space-grade systems |
| Thermal Resistance θJC | 10 °C/W junction-to-end-cap - determines required heatsinking for sustained 5 W operation |
| Surge Current IZSM | 17.6 A @ 8.3 ms - supports transient overvoltage clamping without failure |
| Reverse Leakage IR | 175 μA @ VR = 0.75 V - low leakage preserves accuracy in high-impedance bias networks |
Pinout & Package
Package: Hermetically sealed voidless hard glass case with tungsten slugs; end caps are copper with Sn/Pb finish; polarity indicated by cathode band; marked "E" or "D-5B" outline; weight 539 mg.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to circuit ground or lower potential node during Zener operation |
| Cathode | Reverse breakdown terminal | Connected to regulated voltage rail; band-marked end cap for visual identification |
Key Features
| Feature | Design Value |
|---|---|
| Category III metallurgical bond | Ensures mechanical integrity and hermeticity under shock/vibration in flight-critical systems |
| Triple-layer passivation | Prevents surface contamination-induced parameter drift over 20+ year service life |
| Nonsensitive to ESD | Withstands >8 kV HBM per MIL-STD-750 Method 1020 without parameter shift |
| Inherent radiation hardness | Validated per Microsemi MicroNote 050 for total ionizing dose >100 krad(Si) |
| EIA-481-B tape-and-reel packaging | Enables direct placement on high-speed SMT lines without manual handling or rework |
Applications
| Avionics Power Conditioning | Downhole Sensor Reference |
|---|---|
|
Use Scenario: Regulating auxiliary 3.9 V rail for inertial measurement unit (IMU) analog front-end in jet engine control systems. IC Role / Device Role / Timing Role: Shunt voltage reference providing stable bias for precision op-amps and ADC drivers. Use Value: Maintains <±10 mV regulation error across –55 °C to +125 °C ambient with no calibration drift over 15-year MTBF. |
Use Scenario: Establishing fixed reference voltage for pressure transducer signal conditioning in oil/gas well logging tools. IC Role / Device Role / Timing Role: Precision Zener shunt regulator compensating for wide-temperature sensor offset drift. Use Value: Delivers <0.5 % voltage error over –65 °C to +175 °C with zero parametric shift after 500 thermal cycles. |
| Military Radio Bias Supply | Satellite Payload Voltage Clamp |
|
Use Scenario: Providing stable 3.9 V reference for RF power amplifier bias control in tactical HF radios. IC Role / Device Role / Timing Role: High-reliability shunt regulator maintaining PA linearity under EMI-rich battlefield conditions. Use Value: Survives 20 kV ESD events and 100 krad(Si) TID exposure while retaining regulation within spec. |
Use Scenario: Clamping bus voltage spikes induced by single-event transients (SETs) in LEO satellite power distribution units. IC Role / Device Role / Timing Role: Radiation-hardened Zener clamp absorbing >17 A surge pulses without latch-up or degradation. Use Value: Limits transient overvoltage to <4.5 V for 100 ns, protecting downstream ASICs from destructive latch-up. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N6634US | No TR suffix; bulk pack instead of tape-and-reel; identical electrical and mechanical specs | Preferred for prototyping or low-volume hand-soldered builds where reel packaging is unnecessary | Select 1N6634US/TR when automated SMT placement is required; choose 1N6634US for bench evaluation or repair kits |
| 1N6633US/TR | 3.6 V nominal Zener voltage (vs. 3.9 V); same package, thermal, and reliability specs | Used where system tolerance stack-up requires slightly lower reference voltage with identical ruggedization | Choose 1N6633US/TR only if design specifically calls for 3.6 V regulation; not a drop-in replacement for 3.9 V circuits |
Compared with 1N6634US/TR, the 1N6634US lacks tape-and-reel packaging but matches all performance parameters, while 1N6633US/TR shifts the regulation point downward by 0.3 V-requiring recalibration of feedback networks in closed-loop regulators.
Availability
1N6634US/TR is available at Aetrix Electronics and suitable for avionics power conditioning, downhole sensor reference, and military radio bias supply requiring stable component supply across extended temperature ranges and long product lifecycles.
Supply support for 1N6634US/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) designs high-reliability semiconductor components for aerospace, defense, and industrial markets, with emphasis on radiation-hardened, high-temperature, and hermetically sealed devices.
The 1N6634US/TR belongs to Microsemi's military-qualified surface-mount Zener series built for MIL-PRF-19500/356 compliance, targeting applications where failure is not an option-including flight control, nuclear instrumentation, and deep-earth exploration.
FAQ
What is the Zener voltage tolerance for 1N6634US/TR?
The 1N6634US/TR has a nominal Zener voltage of 3.9 V with a standard tolerance of ±5%, as specified in the Electrical Characteristics table at IZT = 320 mA. No suffix indicates this default tolerance; tighter tolerances (e.g., ±2% or ±1%) require C or D suffixes not present in this part number. The 1N6634US/TR maintains this tolerance across its full operating temperature range.
Does 1N6634US/TR meet MIL-PRF-19500/356 requirements?
Yes, the 1N6634US/TR is qualified to MIL-PRF-19500/356 as a Category III Zener diode, with internal metallurgical bonds meeting the specification's mechanical and environmental robustness requirements. It supports JAN, JANTX, JANTXV, and JANS screening levels, and its voidless-glass hermetic construction satisfies the standard's sealing and reliability criteria.
What is the maximum continuous Zener current for 1N6634US/TR?
The maximum continuous Zener current (IZM) for 1N6634US/TR is 1220 mA, derived from its 5 W power rating and 3.9 V nominal Zener voltage (P = V × I). This value assumes operation at TEC = 125 °C; above that temperature, linear derating applies until zero power at +175 °C junction temperature.
How does the thermal resistance of 1N6634US/TR compare to other 5 W Zeners?
The 1N6634US/TR has a junction-to-end-cap thermal resistance (θJC) of 10 °C/W, higher than the 7 °C/W of the 1N49xxUS series but optimized for its Category III metallurgical bond and voidless-glass construction. This value reflects its intended use with conductive mounting to metal chassis or heat-spreading PCB layers-not standalone board-level dissipation.
Is 1N6634US/TR compatible with lead-free soldering processes?
The 1N6634US/TR features end caps with Sn/Pb finish, making it incompatible with Pb-free reflow profiles. Its maximum peak reflow temperature is limited by the glass-to-metal seal integrity; Microsemi documentation specifies compatibility only with Sn63/Pb37 eutectic solder profiles. For RoHS-compliant designs, consult Microchip's updated 1N6634US-TR-LF variant or alternative qualified parts.
1N6634US/TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- SQ-MELF, E
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 3.9 V
- Tolerance:
- ±5%
- Power - Max:
- 5 W
- Impedance (Max) (Zzt):
- 2 Ohms
- Current - Reverse Leakage @ Vr:
- 175 µA @ 1 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.5 V @ 1 A
- Operating Temperature:
- -65°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- E-MELF
1N6634US/TR FAQ
1.How can I place an order for 1N6634US/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N6634US/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 1N6634US/TR reliable?
The price and inventory of 1N6634US/TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N6634US/TR is usually 5 days.
3.What payment methods are accepted for 1N6634US/TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N6634US/TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N6634US/TR?
1N6634US/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N6634US/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 1N6634US/TR?
For technical support, including 1N6634US/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N6634US/TR requirements.
6.How does Aetrix verify that 1N6634US/TR is sourced from the original manufacturer or authorized distributors?
All 1N6634US/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 1N6634US/TR meets industry standards.
7.What is the process for return or replacement of 1N6634US/TR?
All 1N6634US/TR units undergo pre-shipment inspection (PSI). If there is an issue with 1N6634US/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 1N6634US/TR part is unused and in its original packaging.
Return procedure for 1N6634US/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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