My Inquiry
My Account
Microchip Technology 1N4121
- Part No.:
- 1N4121
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-213AA
- Datasheet:
-
1N4121.pdf
- Description:
- DIODE ZENER 33V 400MW DO213AA
- Quantity:
- Payment:
- Shipping:
Inventory:9,815
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
1N4121 from Microsemi is a 500 mW, 33 V Zener diode in DO-35 glass package, qualified to JANTXV level per MIL-PRF-19500/435. It delivers ±5% voltage tolerance, 200 Ω dynamic impedance at 250 mA test current, and operates across –65 °C to +175 °C for high-reliability voltage regulation in aerospace power supplies.
For engineers reviewing the 1N4121 datasheet, 1N4121 pinout, 1N4121 application, or 1N4121 equivalent, key selection criteria include its 33 V nominal Zener voltage, 250 mA test current, 200 Ω dynamic impedance, 0.01 µA reverse leakage at 25.1 V, and JANTXV qualification for radiation-hardened systems.
Technical Context
This device functions as a precision shunt voltage regulator with metallurgically bonded construction for stable breakdown behavior under thermal and radiation stress. Its low noise density (≤1 µV/√Hz below 6.8 V) and minimal capacitance support low-noise analog references and stable biasing in RF front-ends.
The 1N4121 exhibits a +0.095 %/°C temperature coefficient and linear power derating from 500 mW at 25 °C to zero at 175 °C. It is polarity-marked with cathode band and requires banded end to be positive during Zener operation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage VZ | 33.0 V at 250 mA - precise reference point for regulated output in feedback loops |
| Power Dissipation | 500 mW at 25 °C - supports continuous regulation in compact axial-leaded layouts |
| Dynamic Impedance ZZT | 200 Ω at 250 mA - ensures <1% output variation over load current changes |
| Reverse Leakage IR | 0.01 µA at 25.1 V - enables ultra-low standby current in battery-backed circuits |
| Temp Coefficient αVZ | +0.095 %/°C - predictable drift for compensated reference designs |
| Junction Temp Range | –65 °C to +175 °C - validated for extended-range military and downhole applications |
| Package | DO-35 (DO-204AH) - standard axial-glass form factor compatible with through-hole wave soldering |
Pinout & Package
DO-35 (DO-204AH) hermetically sealed axial-leaded glass package with cathode indicated by color band. Leads are tin-lead or RoHS-compliant matte-tin plated, solderable per MIL-STD-750 method 2026.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Non-banded lead | Connected to system ground or lower-potential node during Zener operation |
| Cathode | Banded lead | Connected to regulated voltage node; must be held positive relative to anode |
Key Features
| Feature | Design Value |
|---|---|
| Metallurgical bond construction | Eliminates interfacial delamination risk under thermal cycling and mechanical shock |
| JANTXV qualification | Validated reliability for space-grade and critical avionics power conditioning |
| Low noise density | ≤1 µV/√Hz - preserves signal integrity in precision analog sensor interfaces |
| Hermetic glass seal | Prevents moisture ingress and long-term parameter drift in humid environments |
| Radiation hardness | Inherently resistant to TID effects per Microsemi MicroNote 050 - no additional shielding required |
Applications
| Aerospace Power Regulation | Test Equipment Reference |
|---|---|
Use Scenario: Regulating +33 V rail in satellite DC-DC converter feedback networks. IC Role / Device Role / Timing Role: Shunt voltage reference providing stable setpoint for error amplifier comparison. Use Value: JANTXV qualification and –65 °C to +175 °C operation ensure uninterrupted regulation across orbital thermal extremes. | Use Scenario: Precision voltage reference in automated calibration fixtures for multimeters. IC Role / Device Role / Timing Role: Stable 33 V Zener source for DMM range calibration against NIST-traceable standards. Use Value: ±5% tolerance and 200 Ω dynamic impedance enable repeatable 0.1% measurement accuracy over 10,000-cycle test life. |
| Military Radio Biasing | Downhole Sensor Conditioning |
Use Scenario: Providing bias voltage to RF power amplifier stages in handheld tactical radios. IC Role / Device Role / Timing Role: Low-noise Zener shunt regulating gate bias to maintain amplifier linearity. Use Value: ≤1 µV/√Hz noise density prevents AM sideband distortion in 30–88 MHz transmit paths. | Use Scenario: Stabilizing excitation voltage for piezoresistive pressure transducers in oil/gas well logging tools. IC Role / Device Role / Timing Role: High-temp-stable reference enabling accurate strain-to-voltage conversion at 175 °C. Use Value: +0.095 %/°C tempco and 175 °C max junction temperature allow direct mounting on transducer housing without external compensation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4121US | Same electrical specs; DO-213AA surface-mount package instead of DO-35 | Requires SMT reflow process; unsuitable for through-hole prototyping or manual repair | Select when board space is constrained and automated assembly is used |
| 1N4755A | 33 V, ±5%, 1 W rating; TO-204AE (DO-41) package; higher power but non-mil-qualified | Lacks JANTXV qualification and radiation hardness; not approved for flight hardware | Select for commercial industrial controls where cost and power margin outweigh reliability requirements |
Compared with 1N4121, the 1N4121US offers identical regulation performance in a smaller footprint but demands SMT infrastructure, while the 1N4755A provides higher power headroom without military qualification or radiation tolerance-making it suitable only for non-critical commercial use.
Availability
1N4121 is available at Aetrix Electronics and suitable for aerospace power regulation, test equipment reference, and military radio biasing requiring stable component supply with full traceability and lifecycle management.
Supply support for 1N4121 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 defense-grade analog and mixed-signal components.
The 1N4121 belongs to Microsemi's legacy MIL-PRF-19500/435-qualified Zener diode family, designed specifically for voltage regulation in mission-critical aerospace, defense, and downhole instrumentation systems.
FAQ
What is the Zener voltage tolerance for the 1N4121?
The 1N4121 has a nominal Zener voltage of 33.0 V with a standard tolerance of ±5%, as defined in the JEDEC-registered specification and confirmed in the Electrical Characteristics table on page 3 of Microsemi's T4-LDS-0245-2 datasheet. This tolerance applies at 250 mA test current and 25 °C ambient temperature.
Is the 1N4121 suitable for high-temperature environments?
Yes, the 1N4121 is rated for junction temperatures from –65 °C to +175 °C and is explicitly qualified to JANTXV level per MIL-PRF-19500/435. Its metallurgically bonded construction and hermetic DO-35 package ensure stable 33 V regulation in downhole, engine bay, and spacecraft thermal environments.
Does the 1N4121 have radiation hardness certification?
Yes, the 1N4121 is inherently radiation hard as documented in Microsemi MicroNote 050. Its glass-encapsulated, metallurgically bonded structure provides proven resistance to total ionizing dose (TID), making it suitable for satellite and nuclear instrumentation without supplemental shielding.
What is the maximum reverse leakage current for the 1N4121?
The 1N4121 specifies a maximum reverse leakage current (IR) of 0.01 µA at 25.1 V, per the Electrical Characteristics table on page 3 of the T4-LDS-0245-2 datasheet. This ultra-low leakage supports energy-efficient biasing in battery-powered and low-power sensor nodes.
Can the 1N4121 be used as a direct replacement for the 1N4755A?
No-the 1N4121 is not a direct replacement for the 1N4755A. While both regulate at 33 V, the 1N4121 is JANTXV-qualified, DO-35 packaged, and rated for 500 mW, whereas the 1N4755A is commercial-grade, DO-41 packaged, and rated for 1 W. Their qualification levels, thermal profiles, and mechanical fit differ significantly.
1N4121 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- DO-213AA
- Packaging:
- Bulk
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 33 V
- Tolerance:
- ±5%
- Power - Max:
- 400 mW
- Impedance (Max) (Zzt):
- 200 Ohms
- Current - Reverse Leakage @ Vr:
- 10 nA @ 25.08 V
- Voltage - Forward (Vf) (Max) @ If:
- 1 V @ 200 mA
- Operating Temperature:
- -65°C ~ 200°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-213AA
1N4121 FAQ
1.How can I place an order for 1N4121 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4121 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 1N4121 reliable?
The price and inventory of 1N4121 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4121 is usually 5 days.
3.What payment methods are accepted for 1N4121?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4121 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4121?
1N4121 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4121 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 1N4121?
For technical support, including 1N4121 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4121 requirements.
6.How does Aetrix verify that 1N4121 is sourced from the original manufacturer or authorized distributors?
All 1N4121 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 1N4121 meets industry standards.
7.What is the process for return or replacement of 1N4121?
All 1N4121 units undergo pre-shipment inspection (PSI). If there is an issue with 1N4121, 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 1N4121 part is unused and in its original packaging.
Return procedure for 1N4121:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N4121 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…
