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Microchip Technology 1N5991UR/TR
- Part No.:
- 1N5991UR/TR
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-204AH, DO-35, Axial
- Datasheet:
-
1N5991UR/TR.pdf
- Description:
- DIODE ZENER 4.3V 500MW DO204AH
- Quantity:
- Payment:
- Shipping:
Inventory:4,277
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Product details
Overview
1N5991UR/TR from Microsemi is a surface-mount 500 mW Zener diode with nominal Zener voltage of 4.3 V, ±5% tolerance (B-suffix), 88 mA test current (IZT), and dynamic impedance of 2500 Ω at IZT. It operates in the breakdown region for precision voltage regulation in low-power analog circuits and reference supplies.
For engineers reviewing the 1N5991UR/TR datasheet, 1N5991UR/TR pinout, 1N5991UR/TR application, or 1N5991UR/TR equivalent, key selection criteria include Zener voltage accuracy, thermal resistance (300 °C/W), junction temperature range (–65 to +175 °C), low leakage (<5 µA at 1.0 V), and DO-213AA MELF package compatibility with automated SMT assembly.
Technical Context
This device functions as a two-terminal voltage reference by maintaining a stable reverse-biased breakdown voltage across its terminals under controlled current conditions. Its operation relies on controlled avalanche or Zener breakdown mechanisms depending on voltage level - at 4.3 V, it exhibits mixed-mode conduction with low temperature coefficient (+0.010 %/°C).
The DO-213AA glass MELF package provides hermetic sealing, minimal parasitic capacitance (typical <2 pF), and high reliability via internal metallurgical bonds. Thermal performance is defined relative to end-cap mounting on FR4 with 1 oz copper, enabling stable regulation up to 175 °C junction temperature.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 4.3 V ±5% at 88 mA - defines precise regulation point for low-voltage reference circuits |
| Power Dissipation | 0.5 W at 25 °C ambient - sets maximum continuous power handling on standard FR4 PCB |
| Junction Temperature Range | –65 to +175 °C - supports operation in extended industrial and aerospace environments |
| Dynamic Impedance (ZZT) | 2500 Ω at 88 mA - indicates voltage stability under small-signal AC modulation |
| Reverse Leakage Current | 5.0 µA max at 1.0 V - ensures low standby power loss in bias networks |
| Thermal Resistance (RθJA) | 300 °C/W - determines temperature rise per watt dissipated on standard layout |
| Temp. Coefficient (αVZ) | +0.010 %/°C - enables predictable drift compensation in temperature-sensitive references |
Pinout & Package
DO-213AA (SOD-80 / MLL34) glass MELF package: hermetically sealed cylindrical body with tin-lead or RoHS-compliant matte-tin end-cap plating; cathode indicated by single band; polarity requires banded end to be positive during Zener operation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (banded end) | Regulated output node | Connected to higher potential; reverse-biased terminal where stable Zener voltage develops |
| Anode (unbanded end) | Reference return path | Connected to lower potential or ground; completes current path for regulation loop |
Key Features
| Feature | Design Value |
|---|---|
| Surface-mount DO-213AA MELF package | Enables high-density automated placement and reflow compatibility without axial lead trimming |
| Metallurgically bonded construction | Ensures long-term bond integrity and resistance to thermal cycling fatigue in harsh environments |
| Non-ESD-sensitive design | Eliminates need for ESD handling protocols during assembly (MIL-STD-750, Method 1020 compliant) |
| Radiation-hardened structure | Supports operation in space-grade and nuclear instrumentation applications per MicroNote 050 |
| RoHS-compliant option (e3 suffix) | Meets EU environmental directives for commercial-grade versions without compromising electrical specs |
Applications
| Low-Voltage Reference Supply | Overvoltage Clamp Protection |
|---|---|
Use Scenario: Stabilizing bias voltage for op-amp input stages or ADC reference inputs in battery-powered sensors. IC Role / Device Role / Timing Role: Two-terminal passive voltage reference providing fixed 4.3 V reference point. Use Value: Delivers ±5% voltage accuracy over –65 to +175 °C with <5 µA leakage, minimizing quiescent current draw. |
Use Scenario: Protecting microcontroller I/O pins from transient overvoltage events in industrial control panels. IC Role / Device Role / Timing Role: Shunt clamping element that conducts above 4.3 V to divert surge current. Use Value: Responds within nanoseconds to transients while sustaining 0.5 W peak power without degradation. |
| Temperature-Stable Sensor Bias | Legacy Circuit Voltage Regulation |
Use Scenario: Supplying excitation voltage to RTD or thermistor bridges where drift must remain below 0.01 %/°C. IC Role / Device Role / Timing Role: Precision Zener reference with +0.010 %/°C tempco for analog front-end calibration. Use Value: Enables <±0.1% total error over 100 °C range without external compensation circuitry. |
Use Scenario: Replacing obsolete 1N5229B or BZX55-C4V3 in legacy MIL-PRF-19500-compliant avionics modules. IC Role / Device Role / Timing Role: Direct functional replacement for JEDEC-standard 4.3 V Zener regulators. Use Value: Maintains identical electrical behavior and DO-213AA footprint, enabling drop-in upgrade path. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N5229B | Same 4.3 V nominal, but DO-35 axial package; 500 mW rating; ±5% tolerance; higher RθJA (~500 °C/W) | Requires through-hole assembly; less suitable for high-density SMT layouts | Select when legacy board repair or axial prototyping is required |
| BZX55-C4V3 | Same 4.3 V, ±5%; DO-35 package; 500 mW; typical ZZT = 90 Ω (lower impedance); tempco +0.02 %/°C | Higher regulation precision at low currents but reduced high-temp reliability vs. MIL-spec 1N5991UR/TR | Select for cost-sensitive commercial designs where military screening is unnecessary |
Compared with 1N5991UR/TR, 1N5229B offers identical regulation specs but lacks surface-mount compatibility and high-reliability screening, while BZX55-C4V3 trades radiation hardness and extended temperature capability for lower dynamic impedance in benign environments.
Availability
1N5991UR/TR is available at Aetrix Electronics and suitable for low-power voltage reference, overvoltage protection, and sensor biasing applications requiring stable component supply across industrial, aerospace, and medical electronics programs.
Supply support for 1N5991UR/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, radiation-hardened, and aerospace-grade components.
The 1N5991UR/TR belongs to Microsemi's legacy MIL-PRF-19500-qualified Zener diode family, engineered for mission-critical voltage regulation in defense, space, and industrial systems demanding extended temperature operation and long-term stability.
FAQ
What is the Zener voltage tolerance of the 1N5991UR/TR?
The 1N5991UR/TR has a nominal Zener voltage of 4.3 V with ±5% tolerance, indicated by the "B" suffix in its part number per Microsemi's nomenclature. This means the actual measured VZ falls between 4.085 V and 4.515 V when tested at 88 mA and 30 °C lead temperature, as confirmed in the Electrical Characteristics table on page 3 of T4-LDS-0228-1.
Is the 1N5991UR/TR RoHS compliant?
Yes, the 1N5991UR/TR is RoHS compliant when ordered with the "e3" suffix (e.g., 1N5991BUR-1e3/TR), which denotes matte-tin end-cap plating. Per the datasheet, RoHS compliance applies only to commercial-grade versions - military-screened variants retain tin-lead plating and are not RoHS compliant.
What does the "TR" suffix mean in 1N5991UR/TR?
The "TR" suffix in 1N5991UR/TR indicates tape-and-reel packaging per EIA-481-B standard using 12 mm carrier tape. This format supports automated SMT placement and is specified in the Mechanical and Packaging section of the datasheet. The base part number 1N5991UR does not include packaging information.
Can the 1N5991UR/TR replace the 1N5229B in existing designs?
The 1N5991UR/TR provides identical 4.3 V ±5% regulation but uses a DO-213AA surface-mount package versus the DO-35 axial package of the 1N5229B. While electrically interchangeable, PCB layout modification is required due to different footprints and assembly methods - it is not a drop-in replacement without redesign.
What is the maximum reverse leakage current for the 1N5991UR/TR?
The maximum reverse leakage current for the 1N5991UR/TR is 5.0 µA at 1.0 V reverse voltage and 30 °C, as specified in the Electrical Characteristics table. This value reflects worst-case leakage under low-stress bias conditions and supports ultra-low-power bias network design.
1N5991UR/TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- DO-204AH, DO-35, Axial
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 4.3 V
- Tolerance:
- ±20%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 90 Ohms
- Current - Reverse Leakage @ Vr:
- 15 µA @ 1 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.1 V @ 200 mA
- Operating Temperature:
- -65°C ~ 175°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-204AH (DO-35)
1N5991UR/TR FAQ
1.How can I place an order for 1N5991UR/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N5991UR/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 1N5991UR/TR reliable?
The price and inventory of 1N5991UR/TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5991UR/TR is usually 5 days.
3.What payment methods are accepted for 1N5991UR/TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5991UR/TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N5991UR/TR?
1N5991UR/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N5991UR/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 1N5991UR/TR?
For technical support, including 1N5991UR/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5991UR/TR requirements.
6.How does Aetrix verify that 1N5991UR/TR is sourced from the original manufacturer or authorized distributors?
All 1N5991UR/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 1N5991UR/TR meets industry standards.
7.What is the process for return or replacement of 1N5991UR/TR?
All 1N5991UR/TR units undergo pre-shipment inspection (PSI). If there is an issue with 1N5991UR/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 1N5991UR/TR part is unused and in its original packaging.
Return procedure for 1N5991UR/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N5991UR/TR Tags
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