My Inquiry
My Account
Microchip Technology 1N4121UR-1/TR
- Part No.:
- 1N4121UR-1/TR
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-213AA
- Datasheet:
-
1N4121UR-1/TR.pdf
- Description:
- DIODE ZENER 33V 500MW DO213AA
- Quantity:
- Payment:
- Shipping:
Inventory:81
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
1N4121UR-1/TR from Microsemi is a hermetically sealed, glass MELF-style 0.5 W Zener diode with nominal Zener voltage of 33 V, ±5% tolerance (no suffix), 250 mA test current, and 200 Ω maximum Zener impedance at IZT. It operates across –65 °C to +175 °C and regulates voltage in precision reference and overvoltage protection circuits.
For engineers reviewing the 1N4121UR-1/TR datasheet, 1N4121UR-1/TR pinout, 1N4121UR-1/TR application, or 1N4121UR-1/TR equivalent, key selection criteria include its DO-213AA package, low noise density (1 µV/√Hz), tight thermal stability (αVZ = +0.085 %/°C), and tape-and-reel availability (TR suffix) for automated SMT assembly.
Technical Context
This device functions as a two-terminal voltage reference diode operating in reverse breakdown, with regulation established by controlled avalanche and Zener mechanisms depending on voltage range. Its 33 V nominal Zener voltage places it in the avalanche-dominated region, delivering stable regulation under varying load and temperature conditions.
The DO-213AA (SOD-80/MLL34) glass MELF package provides hermetic sealing, ESD immunity per MIL-STD-750 Method 1020, and minimal parasitic capacitance (<1.5 pF typical at 33 V), supporting high-frequency stability in analog and power-supply feedback paths.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Zener Voltage (VZ) | 33 V at 250 mA test current - defines precise regulation point for feedback and reference circuits |
| Zener Tolerance | ±5% - standard industrial-grade accuracy without suffix; no C/D suffix present in part number |
| Power Dissipation | 0.5 W at TEC < 100 °C - limits continuous current to ~15 mA at full rating in ambient conditions |
| Zener Impedance (ZZT) | 200 Ω max at 250 mA - ensures low dynamic resistance for stable regulation under transient loads |
| Noise Density | 1 µV/√Hz - enables use in low-noise voltage references and precision analog signal chains |
| Operating Temperature | –65 °C to +175 °C - supports aerospace, downhole, and high-reliability industrial environments |
| Thermal Resistance | 150 °C/W junction-to-end-cap - informs heatsinking requirements when mounted to metalized PCB pads |
Pinout & Package
DO-213AA (SOD-80 / MLL34) glass MELF package: hermetically sealed cylindrical body with tin-lead or RoHS-compliant matte-tin end caps; cathode indicated by single band; polarity critical - banded end must be positive during Zener operation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (banded end) | Anode of reverse-biased junction | Connected to higher potential node; establishes Zener breakdown path when reverse biased |
| Anode (unbanded end) | Cathode of reverse-biased junction | Connected to lower potential node; completes regulation loop in shunt configuration |
Key Features
| Feature | Design Value |
|---|---|
| Hermetic glass MELF construction | Eliminates moisture ingress and long-term parameter drift in harsh environments |
| Internal metallurgical bond (-1 suffix) | Enhances thermal cycling reliability and mechanical robustness for military-grade applications |
| Low noise density (1 µV/√Hz) | Reduces ripple and error in precision voltage references and sensor excitation circuits |
| ESD immunity (MIL-STD-750 Method 1020) | Enables handling and assembly without special ESD controls in production lines |
| Tape-and-reel packaging (TR suffix) | Supports high-speed pick-and-place placement with 2000 units per 7-inch reel |
Applications
| Industrial Power Supply Feedback | Aerospace Voltage Reference |
|---|---|
Use Scenario: Regulating output voltage in isolated DC-DC converters using optocoupler feedback loops. IC Role / Device Role / Timing Role: Shunt voltage reference providing stable 33 V reference for TL431-like comparator circuits. Use Value: Maintains ±1% output regulation across line, load, and temperature with minimal drift (αVZ = +0.085 %/°C). |
Use Scenario: Providing primary reference voltage in radiation-hardened avionics power management units. IC Role / Device Role / Timing Role: Precision Zener reference in fault-tolerant voltage monitoring subsystems. Use Value: Inherent radiation hardness per MicroNote 050 and operational stability from –65 °C to +175 °C ensure mission-critical uptime. |
| Test Equipment Calibration | Downhole Oil & Gas Sensor Biasing |
Use Scenario: Generating traceable 33 V reference in portable multimeters and calibration sources. IC Role / Device Role / Timing Role: Low-noise shunt regulator establishing metrology-grade reference for ADC front-ends. Use Value: 1 µV/√Hz noise density minimizes measurement uncertainty in sub-mV resolution systems. |
Use Scenario: Biasing high-temperature pressure transducers in oil well logging tools. IC Role / Device Role / Timing Role: High-temperature-stable Zener element in sensor excitation circuitry. Use Value: Guaranteed operation up to +175 °C eliminates need for external cooling or derating in deep-well deployments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4121UR-1 | Same electrical specs but includes internal metallurgical bond; requires separate datasheet | Higher reliability under thermal cycling and mechanical shock; qualified for JAN/JANTXV | Select when extended lifetime in aerospace or defense systems is required |
| BZX84-C33LT1G | 33 V, ±5%, SOT-23 package; 350 mW rating; 600 Ω ZZT; 30 nA IR @ 26.4 V | Surface-mount plastic package; lower power and higher impedance; not hermetic or radiation-hard | Choose for cost-sensitive commercial designs where hermeticity and extreme temp range are unnecessary |
Compared with 1N4121UR-1/TR, the 1N4121UR-1 offers enhanced mechanical reliability for mission-critical use, while BZX84-C33LT1G provides compact SMT integration at reduced performance margins - neither is pin-compatible due to DO-213AA vs. SOT-23 and DO-213AA vs. metallurgically bonded variants.
Availability
1N4121UR-1/TR is available at Aetrix Electronics and suitable for industrial power supplies, aerospace voltage references, and downhole sensor biasing requiring stable component supply, long-lifecycle assurance, and traceable sourcing.
Supply support for 1N4121UR-1/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) is a U.S.-based semiconductor company specializing in high-reliability, radiation-hardened, and high-temperature analog and mixed-signal components.
The 1N4121UR-1/TR belongs to Microsemi's legacy DO-213AA glass Zener family, engineered for extreme-environment voltage regulation where hermeticity, wide temperature operation, and low noise are mandatory.
FAQ
What is the Zener voltage tolerance for 1N4121UR-1/TR?
The 1N4121UR-1/TR has a nominal Zener voltage of 33 V with a standard tolerance of ±5%, as indicated by the absence of a C (±2%) or D (±1%) suffix. This tolerance applies under standard test conditions at 25 °C with 250 mA Zener test current, per JEDEC registration and Microsemi's datasheet revision D.
Does 1N4121UR-1/TR have a cathode band, and how is polarity identified?
Yes, the 1N4121UR-1/TR features a single cathode band on the glass body. During Zener operation, the banded end must be held at a higher potential than the unbanded end - i.e., the device is reverse-biased with cathode positive. This polarity is essential for proper regulation and is consistent across all DO-213AA Zeners in the series.
What does the "-1" suffix in 1N4121UR-1/TR signify?
The "-1" suffix in 1N4121UR-1/TR denotes internal metallurgical bonding between the silicon die and end caps, improving thermal cycling endurance and mechanical reliability. This variant is documented in a separate Microsemi datasheet and qualifies for JAN/JANTX/JANTXV military specifications - distinct from the base 1N4121UR.
Is 1N4121UR-1/TR RoHS compliant?
Yes, the "e3" designation in the full part number family confirms RoHS compliance. The 1N4121UR-1/TR uses annealed matte-tin plating on end caps per MIL-STD-750 Method 2026, replacing traditional tin-lead finishes while maintaining solderability and reliability in high-temperature reflow profiles.
What is the maximum steady-state power dissipation for 1N4121UR-1/TR?
The 1N4121UR-1/TR is rated for 0.5 W steady-state power dissipation when the end cap temperature (TEC) remains below 100 °C or ambient temperature (TA) stays below 25 °C on FR4 board with recommended footprint. Derating is required above these temperatures per Figure 2 in the datasheet, reaching zero power at 175 °C ambient.
1N4121UR-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):
- 33 V
- Tolerance:
- ±5%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 200 Ohms
- Current - Reverse Leakage @ Vr:
- 10 nA @ 25.1 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.1 V @ 200 mA
- Operating Temperature:
- -65°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-213AA
1N4121UR-1/TR FAQ
1.How can I place an order for 1N4121UR-1/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4121UR-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 1N4121UR-1/TR reliable?
The price and inventory of 1N4121UR-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 1N4121UR-1/TR is usually 5 days.
3.What payment methods are accepted for 1N4121UR-1/TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4121UR-1/TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4121UR-1/TR?
1N4121UR-1/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4121UR-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 1N4121UR-1/TR?
For technical support, including 1N4121UR-1/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4121UR-1/TR requirements.
6.How does Aetrix verify that 1N4121UR-1/TR is sourced from the original manufacturer or authorized distributors?
All 1N4121UR-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 1N4121UR-1/TR meets industry standards.
7.What is the process for return or replacement of 1N4121UR-1/TR?
All 1N4121UR-1/TR units undergo pre-shipment inspection (PSI). If there is an issue with 1N4121UR-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 1N4121UR-1/TR part is unused and in its original packaging.
Return procedure for 1N4121UR-1/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N4121UR-1/TR Tags
-
MMBZ5240B-7-F
Diodes Incorporated
-
BZT52C5V6T-7
Diodes Incorporated
-
MMSZ5231B-7-F
Diodes Incorporated
-
BZT52C15-7-F
Diodes Incorporated
-
BZX84C3V3LT1G
onsemi
-
MMSZ5245BS-7-F
Diodes Incorporated
-
MMSZ4682T1G
onsemi
-
BZT52C15S-7-F
Diodes Incorporated
-
MM5Z5V1ST1G
onsemi
-
SMAJ4744A-TP
Micro Commercial Co
-
BZT52C3V6LP-7
Diodes Incorporated
-
SMAZ12-13-F
Diodes Incorporated
Tech Hub
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
