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Microchip Technology 1N4989US/TR
- Part No.:
- 1N4989US/TR
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- SQ-MELF, E
- Datasheet:
-
1N4989US/TR.pdf
- Description:
- DIODE ZENER 200V 5W E-MELF
- Quantity:
- Payment:
- Shipping:
Inventory:100
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Product details
Overview
1N4989US/TR from Microsemi is a surface-mount, hermetically sealed, voidless-glass 5 W Zener diode with nominal Zener voltage of 200 V, ±5% tolerance, 500 Ω dynamic impedance at 5 mA, and maximum reverse leakage of 2 μA at 152 V. It operates from –65 °C to +175 °C and is qualified to MIL-PRF-19500/356 for high-reliability voltage regulation in aerospace power conditioning circuits.
For engineers reviewing the 1N4989US/TR datasheet, 1N4989US/TR pinout, 1N4989US/TR application, or 1N4989US/TR equivalent, key selection criteria include its military-grade hermetic glass package, 200 V Zener voltage stability over temperature, low leakage under high-voltage bias, and compatibility with tape-and-reel automated assembly for space-constrained avionics PCBs.
Technical Context
This device belongs to the 1N4954US–1N4996US family of surface-mount Zener regulators, using tungsten slugs and triple-layer passivation within a voidless hard-glass case. Its internal Category I metallurgical bond ensures mechanical integrity under thermal shock and vibration.
It delivers stable 200 V regulation across 10%–50% of IZM (18 mA), with temperature coefficient αVZ = +0.110 %/°C and thermal resistance of 10 °C/W junction-to-end-cap - enabling reliable operation in conduction-cooled military power supplies without forced airflow.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 200 V ±5% at 5 mA - defines precise clamping level for overvoltage protection in 28 V DC bus-derived high-side reference circuits. |
| Power Dissipation | 5 W @ TEC = 125 °C - supports continuous regulation in compact, high-temperature environments without heatsinking. |
| Dynamic Impedance (ZZ) | 500 Ω @ IZT = 5 mA - ensures minimal output voltage shift under load transients in precision reference applications. |
| Reverse Leakage (IR) | 2 μA max @ VR = 152 V - guarantees low standby current in high-impedance bias networks for radiation-hardened analog front-ends. |
| Operating Temperature | –65 °C to +175 °C - validated for use in satellite power systems exposed to deep-space thermal cycling and re-entry heating. |
| Thermal Resistance | 10 °C/W junction-to-end-cap - enables direct thermal coupling to metal-core PCBs or chassis for passive thermal management. |
| Surge Current (IZSM) | 18 A @ 8.3 ms - withstands lightning-induced transients per MIL-STD-461 CS115 without degradation. |
Pinout & Package
Package: Hermetically sealed voidless hard-glass "E" package (also designated D-5B), with copper end caps finished in Sn/Pb, cathode indicated by band, weight 539 mg, and EIA-481-B tape-and-reel compatible.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to system ground or lower-potential rail; must sustain 1.5 V forward drop at 1 A during surge events. |
| Cathode | Zener breakdown terminal | Banded end; connects to regulated node; carries full Zener current and dissipates 5 W under steady-state fault conditions. |
Key Features
| Feature | Design Value |
|---|---|
| Voidless hermetic glass construction | Eliminates moisture ingress and internal delamination - critical for >15-year mission life in vacuum or humid tropical deployments. |
| Category I metallurgical bond | Ensures mechanical continuity between silicon die and tungsten slug under 20,000 g shock - required for launch vehicle electronics. |
| Triple-layer passivation | Provides immunity to ionizing radiation (per MicroNote 050) and prevents surface leakage path formation in high-humidity environments. |
| Nonsensitive to ESD | Withstands ≥4 kV HBM per MIL-STD-750 Method 1020 - simplifies handling in cleanroom assembly without special grounding protocols. |
| MIL-PRF-19500/356 qualification | Validated screening includes burn-in, temperature cycling, and lot acceptance testing - eliminates need for customer requalification. |
Applications
| Aerospace Power Bus Regulation | Satellite Payload Reference Supply |
|---|---|
Use Scenario: Stabilizing 200 V derived from DC-DC converter output in LEO satellite power distribution unit. IC Role / Device Role / Timing Role: Zener voltage reference and overvoltage clamp for downstream FET gate drivers and ADC references. Use Value: Maintains <±0.5% output variation across –40 °C to +85 °C ambient due to low αVZ and hermetic stability. |
Use Scenario: Providing isolated 200 V bias for photomultiplier tube (PMT) anode chains in Earth observation instruments. IC Role / Device Role / Timing Role: High-voltage, low-leakage current source enabling stable gain calibration over 5-year orbital lifetime. Use Value: 2 μA max reverse leakage at 152 V prevents signal drift in ultra-high-impedance PMT feedback networks. |
| Tactical Radio Transmitter Protection | Missile Guidance System Biasing |
Use Scenario: Clamping RF power amplifier drain supply against lightning-induced surges in man-portable radios. IC Role / Device Role / Timing Role: Transient voltage suppressor absorbing 18 A 8.3 ms surges without parametric shift. Use Value: Survives repeated MIL-STD-461 CS115 pulses while retaining 200 V regulation accuracy within spec limits. |
Use Scenario: Generating stable 200 V bias for MEMS gyroscopes and inertial measurement units in hypersonic vehicles. IC Role / Device Role / Timing Role: Radiation-hardened voltage reference supporting analog signal conditioning in high-dose neutron environments. Use Value: Inherent radiation hardness per MicroNote 050 avoids single-event latchup or parameter drift during boost-phase exposure. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4989US (no /TR) | Identical electrical specs and package; differs only in packaging format (bulk vs. tape-and-reel). | No functional difference; /TR suffix denotes EIA-481-B compliant tape-and-reel for SMT placement. | Select 1N4989US/TR when automated pick-and-place is required; choose bulk 1N4989US for manual prototyping or repair. |
| 1N4988US/TR | 180 V nominal Zener voltage (vs. 200 V); otherwise identical package, power rating, and qualification level. | Used where 180 V regulation is specified - e.g., legacy radar transmitter bias rails requiring tighter margin control. | Choose 1N4988US/TR only if system design mandates 180 V clamping; 1N4989US/TR is not substitutable due to 20 V voltage mismatch. |
Compared with 1N4988US/TR and bulk 1N4989US, the 1N4989US/TR provides identical Zener performance and military qualification but adds SMT-ready tape-and-reel packaging - enabling first-pass yield improvement in high-volume avionics production without altering circuit design or layout.
Availability
1N4989US/TR is available at Aetrix Electronics and suitable for aerospace power regulation, satellite payload biasing, and tactical radio surge protection requiring stable component supply across extended temperature ranges and long product lifecycles.
Supply support for 1N4989US/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 analog and mixed-signal semiconductors for defense, aerospace, and industrial markets, with emphasis on radiation-hardened and high-temperature operation.
The 1N49xxUS series was developed specifically for military-grade Zener regulation in harsh-environment power systems, prioritizing hermetic reliability, wide temperature operation, and MIL-PRF-19500 compliance over cost or consumer-grade performance.
FAQ
What is the Zener voltage tolerance for 1N4989US/TR?
The 1N4989US/TR has a nominal Zener voltage of 200 V with a standard tolerance of ±5%, as defined in the Electrical Characteristics table at IZT = 5 mA. No suffix indicates this standard tolerance; tighter tolerances (e.g., ±2% or ±1%) require C or D suffixes not present in this part number. This tolerance remains valid across the full operating temperature range of –65 °C to +175 °C.
Is 1N4989US/TR suitable for space applications?
Yes, the 1N4989US/TR is suitable for space applications due to its MIL-PRF-19500/356 qualification, inherent radiation hardness per Microsemi MicroNote 050, and operational capability from –65 °C to +175 °C. Its voidless hermetic glass package prevents outgassing and moisture-related failure in vacuum, making it appropriate for LEO and GEO satellite power subsystems where long-term reliability is mandatory.
What is the maximum continuous Zener current for 1N4989US/TR?
The maximum continuous Zener current (IZM) for 1N4989US/TR is 18 mA, calculated from its 5 W power rating and 200 V Zener voltage (IZM = PZ/VZ). This value assumes operation at TEC = 125 °C; derating is linear above that temperature, reaching zero current at +175 °C. The device sustains this current continuously without parameter shift when properly mounted to a thermally conductive surface.
Does 1N4989US/TR have a cathode band marking?
Yes, the 1N4989US/TR uses a visible cathode band on the glass body to identify polarity - consistent with JEDEC-standard marking for Zener diodes. The banded end is the cathode and must be connected to the higher-potential node in regulation or clamping configurations. No alphanumeric marking is applied per the datasheet; polarity identification relies solely on the band.
What is the thermal resistance of 1N4989US/TR?
The thermal resistance (RθJC) of 1N4989US/TR is 10 °C/W junction-to-end-cap, as specified for the 1N4954US–1N4996US series. This value reflects conduction through the tungsten slug and copper end cap; effective thermal performance depends on solder joint quality and PCB copper area beneath the end caps. For optimal heat dissipation, mount directly to a large copper pour or metal-core substrate.
1N4989US/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):
- 200 V
- Tolerance:
- ±5%
- Power - Max:
- 5 W
- Impedance (Max) (Zzt):
- 500 Ohms
- Current - Reverse Leakage @ Vr:
- 2 µA @ 152 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
1N4989US/TR FAQ
1.How can I place an order for 1N4989US/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4989US/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 1N4989US/TR reliable?
The price and inventory of 1N4989US/TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4989US/TR is usually 5 days.
3.What payment methods are accepted for 1N4989US/TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4989US/TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4989US/TR?
1N4989US/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4989US/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 1N4989US/TR?
For technical support, including 1N4989US/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4989US/TR requirements.
6.How does Aetrix verify that 1N4989US/TR is sourced from the original manufacturer or authorized distributors?
All 1N4989US/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 1N4989US/TR meets industry standards.
7.What is the process for return or replacement of 1N4989US/TR?
All 1N4989US/TR units undergo pre-shipment inspection (PSI). If there is an issue with 1N4989US/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 1N4989US/TR part is unused and in its original packaging.
Return procedure for 1N4989US/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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