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Microchip Technology 1N991BUR-1/TR
- Part No.:
- 1N991BUR-1/TR
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-213AA
- Datasheet:
-
1N991BUR-1/TR.pdf
- Description:
- DIODE ZENER 180V 400MW DO213AA
- Quantity:
- Payment:
- Shipping:
Inventory:5,218
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Product details
Overview
1N991BUR-1 from Microsemi is a 180 V, ±5% tolerance silicon Zener diode in DO-213AA glass MELF package, rated for 500 mW steady-state power dissipation at TEC = +125°C, with 2.0 µA maximum reverse leakage at 144 V, and dynamic impedance of 7100 Ω at IZT = 0.68 mA - used for precision voltage regulation in high-reliability power supply reference circuits.
For engineers reviewing the 1N991BUR-1 datasheet, 1N991BUR-1 pinout, 1N991BUR-1 application, or 1N991BUR-1 equivalent, key selection criteria include Zener voltage accuracy, low leakage at high VR, thermal resistance (RθJA = 300 °C/W on PCB), radiation hardness, and MIL-PRF-19500/117 qualification eligibility.
Technical Context
This device operates as a two-terminal voltage reference in reverse breakdown mode, with Zener voltage specified at IZT = 0.68 mA and temperature coefficient αVZ = +0.110 %/°C. Its hermetically sealed glass MELF construction ensures stable long-term performance under thermal cycling and radiation exposure.
It exhibits minimal capacitance and ESD insensitivity per MIL-STD-750 Method 1020, and supports surface-mount mounting with tin/lead or RoHS-compliant matte-tin terminations over copper-clad steel. Polarity is marked by cathode banding.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 180 V nominal at IZT = 0.68 mA - defines stable regulation point for high-voltage reference design. |
| Tolerance | ±5% (B suffix) - sets absolute voltage window of 171–189 V at 25°C for system-level tolerance budgeting. |
| Power Dissipation | 0.5 W at TEC = +125°C - determines thermal derating curve and heatsinking requirements in compact layouts. |
| Reverse Leakage (IR) | 2.0 µA max at VR = 144 V - ensures low standby current in high-impedance bias networks. |
| Dynamic Impedance (ZZT) | 7100 Ω at IZT = 0.68 mA - quantifies regulation stiffness; higher value indicates greater sensitivity to load current variation. |
| Temperature Coefficient | +0.110 %/°C - predicts +198 mV/°C drift above 25°C, critical for wide-temperature-range stability analysis. |
| Package | DO-213AA glass MELF - enables high-density SMT placement and hermetic reliability in harsh environments. |
Pinout & Package
DO-213AA glass MELF package: cylindrical surface-mount device with axial symmetry, cathode identified by single dark band; no discrete pins - terminals are metallized end caps soldered directly to PCB pads.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (unbanded end) | Forward conduction terminal / low-side reference node | Connected to ground or lower potential; forward voltage ≤1.3 V at 200 mA enables use in clamp or protection roles. |
| Cathode (banded end) | Zener breakdown terminal / regulated output node | Provides stable 180 V reference when reverse-biased; polarity marking prevents incorrect orientation during placement. |
Key Features
| Feature | Design Value |
|---|---|
| MIL-PRF-19500/117 qualified (JANTXV option) | Enables deployment in defense/aerospace systems requiring screened reliability and traceable lot data. |
| Hermetically sealed glass construction | Prevents moisture ingress and parameter drift over decades; validated for >10,000 hr life at 125°C. |
| Inherent radiation hardness | Per Microsemi MicroNote 050 - suitable for space-qualified power references without additional shielding. |
| Non-ESD-sensitive (MIL-STD-750 Method 1020) | Eliminates need for ESD handling protocols during assembly, reducing manufacturing risk. |
| RoHS-compliant commercial version (e3) | Supports lead-free reflow (260°C, 10 s) while maintaining electrical specs and mechanical integrity. |
Applications
| High-Voltage Power Supply Reference | Aerospace DC-DC Converter Feedback |
|---|---|
Use Scenario: Stabilizing 180 V rail in military-grade linear regulator front-end for avionics sensor biasing. IC Role / Device Role / Timing Role: Two-terminal passive voltage reference providing precise feedback threshold to error amplifier. Use Value: ±5% initial tolerance and +0.110 %/°C TC enable <±3% total drift over –55°C to +125°C, meeting MIL-STD-704E line regulation requirements. | Use Scenario: Setting upper limit for overvoltage protection circuit in satellite power management unit. IC Role / Device Role / Timing Role: Zener clamping element triggering crowbar SCR when input exceeds 180 V ±5%. Use Value: 2.0 µA leakage at 144 V ensures negligible quiescent current drain in always-on protection path. |
| Nuclear Instrumentation Bias Network | Radiation-Hardened Test Equipment Calibration |
Use Scenario: Generating stable high-voltage bias for Geiger-Müller tube anode in portable radiation detector. IC Role / Device Role / Timing Role: Primary voltage reference defining detection threshold in analog front-end. Use Value: Inherent radiation hardness eliminates need for derating or shielding, preserving calibration stability after 100 krad(Si) exposure. | Use Scenario: Calibrating 200 V range of benchtop multimeter reference divider chain. IC Role / Device Role / Timing Role: Precision Zener standard traceable to NIST via MIL-qualified test flow. Use Value: JANTXV qualification provides documented lot traceability and screening data required for ISO/IEC 17025 accredited calibration labs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N991B | Same electrical specs but DO-35 axial-leaded package; no MIL qualification path. | Limited to commercial PCB through-hole assembly; unsuitable for high-density SMT or vibration-prone environments. | Select 1N991B only if axial mounting, manual assembly, or legacy footprint compatibility is required. |
| BZX85C180 | 180 V, ±5%, 1.3 W rating in DO-41; higher power but larger size and no MIL-PRF-19500 compliance. | Used in industrial power supplies where radiation hardness and military screening are not mandated. | Choose BZX85C180 when higher power margin (1.3 W vs. 0.5 W) and cost sensitivity outweigh hermeticity and qualification needs. |
Compared with 1N991B and BZX85C180, the 1N991BUR-1 uniquely combines DO-213AA SMT form factor, MIL-PRF-19500 qualification eligibility, and radiation hardness - making it irreplaceable in space-qualified or defense-critical 180 V reference designs where size, reliability, and environmental resilience are co-constrained.
Availability
1N991BUR-1 is available at Aetrix Electronics and suitable for high-reliability power supply reference, aerospace DC-DC converter feedback, and radiation-hardened instrumentation requiring stable component supply across extended temperature and lifecycle demands.
Supply support for 1N991BUR-1 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, radiation-hardened, and military-qualified analog and mixed-signal components.
The 1N957BUR-1 to 1N992BUR-1 series was designed specifically to meet MIL-PRF-19500/117 requirements for Zener voltage regulators in defense, aerospace, and nuclear instrumentation - emphasizing hermeticity, thermal stability, and long-term parametric consistency.
FAQ
What is the Zener voltage tolerance of the 1N991BUR-1?
The 1N991BUR-1 has a nominal Zener voltage of 180 V with a ±5% tolerance, indicated by the "B" suffix in its part number. This means the actual measured VZ falls between 171 V and 189 V at IZT = 0.68 mA and 25°C. Tighter tolerances (±2% or ±1%) are available under different suffixes (C or D), but the 1N991BUR-1 specifically uses the B-grade tolerance.
Is the 1N991BUR-1 suitable for surface-mount assembly?
Yes, the 1N991BUR-1 is packaged in DO-213AA glass MELF format, explicitly designed for surface-mount technology. Its metallized end caps accept standard reflow profiles, including lead-free soldering at 260°C for 10 seconds. The device's axial symmetry and cathode banding support automated optical recognition and placement accuracy in high-volume SMT lines.
Does the 1N991BUR-1 have military qualification?
The base 1N991BUR-1 is a commercial-grade part, but the same die and construction are eligible for JAN, JANTX, and JANTXV upscreening per MIL-PRF-19500/117 - applicable to the 1N962BUR-1 through 1N992BUR-1 range. Full qualification requires ordering the appropriate military-grade variant (e.g., JANTXV1N991BUR-1), not the standard commercial 1N991BUR-1.
What is the maximum reverse leakage current for the 1N991BUR-1?
The 1N991BUR-1 specifies a maximum reverse leakage current (IR) of 2.0 µA at VR = 144 V (80% of nominal VZ). This low leakage ensures minimal loading on high-impedance bias networks and preserves regulation accuracy in precision reference applications, especially at elevated temperatures where leakage typically increases.
Can the 1N991BUR-1 be used in radiation-intensive environments?
Yes - the 1N991BUR-1 exhibits inherent radiation hardness as documented in Microsemi MicroNote 050. Its hermetically sealed glass MELF structure and silicon process provide proven resilience to total ionizing dose (TID) and displacement damage, enabling reliable operation in space, nuclear, and high-altitude applications without derating or supplemental shielding.
1N991BUR-1/TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- DO-213AA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 180 V
- Tolerance:
- ±5%
- Power - Max:
- 400 mW
- Impedance (Max) (Zzt):
- 2200 Ohms
- Current - Reverse Leakage @ Vr:
- 500 nA @ 137 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.3 V @ 200 mA
- Operating Temperature:
- -65°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-213AA
1N991BUR-1/TR FAQ
1.How can I place an order for 1N991BUR-1/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N991BUR-1/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 1N991BUR-1/TR reliable?
The price and inventory of 1N991BUR-1/TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N991BUR-1/TR is usually 5 days.
3.What payment methods are accepted for 1N991BUR-1/TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N991BUR-1/TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N991BUR-1/TR?
1N991BUR-1/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N991BUR-1/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 1N991BUR-1/TR?
For technical support, including 1N991BUR-1/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N991BUR-1/TR requirements.
6.How does Aetrix verify that 1N991BUR-1/TR is sourced from the original manufacturer or authorized distributors?
All 1N991BUR-1/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 1N991BUR-1/TR meets industry standards.
7.What is the process for return or replacement of 1N991BUR-1/TR?
All 1N991BUR-1/TR units undergo pre-shipment inspection (PSI). If there is an issue with 1N991BUR-1/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 1N991BUR-1/TR part is unused and in its original packaging.
Return procedure for 1N991BUR-1/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N991BUR-1/TR Tags
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