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Microchip Technology 1N5221B
- Part No.:
- 1N5221B
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-204AH, DO-35, Axial
- Datasheet:
-
1N5221B.pdf
- Description:
- DIODE ZENER 2.4V 500MW DO204AH
- Quantity:
- Payment:
- Shipping:
Inventory:6,919
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Product details
Overview
1N5221B from Microsemi is a 2.4 V, ±5% tolerance, 500 mW glass axial-lead Zener diode in DO-35 (DO-204AH) package, rated for 20 mA test current and 30 Ω dynamic impedance at IZT, used for precision low-voltage regulation in power supply reference and voltage clamp circuits.
For engineers reviewing the 1N5221B datasheet, 1N5221B pinout, 1N5221B application, or 1N5221B equivalent, this page delivers verified electrical parameters, thermal derating behavior, Zener voltage temperature coefficient (−0.085 %/°C), RoHS-compliant e3 variant availability, and direct alternatives with documented tolerance and impedance differences.
Technical Context
The 1N5221B operates as a two-terminal voltage reference device with sharp reverse breakdown at 2.4 V under 20 mA DC test current. Its DO-35 glass package enables stable operation from −65 °C to +175 °C, and its 30 Ω Zener impedance at IZT ensures predictable regulation across load variations.
It exhibits a negative temperature coefficient of −0.085 %/°C, confirming stable low-voltage reference performance over temperature. The device is nonsensitive to ESD per MIL-STD-750 Method 1020 and features minimal junction capacitance-critical for noise-sensitive analog references.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Zener Voltage | 2.4 V @ 20 mA - defines precise regulation point for low-voltage reference designs |
| Zener Tolerance | ±5% (B suffix) - guarantees VZ between 2.28 V and 2.52 V at 25 °C |
| Zener Impedance | 30 Ω @ IZT - ensures low AC output impedance for stable regulation under dynamic loads |
| Power Dissipation | 500 mW at 25 °C - sets maximum continuous DC power handling before thermal derating |
| Temperature Coefficient | −0.085 %/°C - quantifies VZ drift with temperature; enables accurate compensation in wide-temp designs |
| Reverse Current | 100 μA @ 1.9 V - specifies leakage threshold below regulation knee; critical for standby power integrity |
| Forward Voltage | ≤1.5 V @ 200 mA - defines conduction drop when used in forward-biased protection or clamping roles |
Pinout & Package
DO-35 (DO-204AH) hermetically sealed glass axial-leaded package with cathode indicated by a single 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 (unbanded end) | Reference ground node | Connected to circuit common; establishes polarity for reverse-bias Zener operation |
| Cathode (banded end) | Regulated output node | Provides stable 2.4 V relative to anode; must be held positive w.r.t. anode for regulation |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC-registered Zener | Complies with JEDEC 1N5221B standard - ensures cross-manufacturer interchangeability and test consistency |
| Low-voltage precision reference | 2.4 V ±5% with −0.085 %/°C TC - supports accurate biasing in sensor interfaces and ADC references |
| Radiation-hardened construction | Inherently radiation hard per MicroNote 050 - suitable for aerospace and high-reliability industrial environments |
| ESD robustness | Nonsensitive per MIL-STD-750 Method 1020 - eliminates need for external ESD protection in board-level integration |
| Thermal stability | Operates continuously from −65 °C to +175 °C - enables use in under-hood automotive and downhole instrumentation |
Applications
| Low-Voltage Power Reference | Overvoltage Clamp |
|---|---|
Use Scenario: Providing stable 2.4 V reference for 8-bit microcontroller reset circuits and analog sensor excitation. IC Role / Device Role / Timing Role: Two-terminal shunt voltage regulator establishing fixed bias point independent of supply ripple. Use Value: Maintains reset threshold accuracy within ±5% across temperature and line variation, preventing spurious reboots. |
Use Scenario: Protecting input pins of op-amps and ADCs against transient overvoltage events up to ±15 V. IC Role / Device Role / Timing Role: Reverse-biased clamping element diverting excess current above 2.4 V to ground. Use Value: Limits voltage excursion to ≤2.4 V + forward drop, preserving signal chain integrity without active control logic. |
| Current-Source Bias Generator | Temperature-Compensated Reference |
Use Scenario: Generating stable bias current for discrete transistor amplifiers using constant-voltage drop across series resistor. IC Role / Device Role / Timing Role: Fixed-voltage node enabling Ohm's Law-based current setting (I = (VSUPPLY − 2.4 V)/R). Use Value: Delivers <1% current variation over −40 °C to +85 °C due to known TC and low ZZT. |
Use Scenario: Building compensated reference strings in precision instrumentation where multiple Zeners offset TC effects. IC Role / Device Role / Timing Role: Low-voltage component in complementary TC pair (e.g., paired with higher-VZ positive-TC Zener). Use Value: Enables net TC < ±25 ppm/°C in composite references for metrology-grade systems. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4728A | 3.3 V nominal, ±5%, 1.0 W rating, DO-41 package | Higher voltage and power; larger footprint; requires PCB layout change | Select when ≥3.3 V reference or >500 mW dissipation is required; not interchangeable for 2.4 V designs |
| BZX55C2V4 | 2.4 V nominal, ±5%, 500 mW, DO-35, 30 Ω ZZT - identical electrical specs but different manufacturer screening and RoHS compliance path | Same regulation point and package; qualified to AEC-Q200 for automotive use | Prefer for automotive production; verify qualification status and lot traceability requirements |
Compared with 1N5221B, 1N4728A provides higher voltage headroom and thermal margin but cannot replace it in 2.4 V circuits, while BZX55C2V4 matches all key electrical and mechanical specs and adds automotive qualification-making it a functionally aligned alternative where AEC-Q200 compliance is mandatory.
Availability
1N5221B is available at Aetrix Electronics and suitable for low-voltage reference design, analog sensor biasing, and overvoltage protection requiring stable component supply across industrial control, test equipment, and legacy embedded systems.
Supply support for 1N5221B 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 precision analog components for aerospace, defense, and industrial markets.
The 1N52xxB series was designed specifically for stable, low-power voltage regulation in harsh-environment applications-emphasizing wide temperature range, ESD immunity, and JEDEC-standardized parametric consistency.
FAQ
What is the nominal Zener voltage and tolerance of the 1N5221B?
The 1N5221B has a nominal Zener voltage of 2.4 V with a guaranteed tolerance of ±5% at 25 °C and 20 mA test current. This means its actual breakdown voltage falls between 2.28 V and 2.52 V under specified conditions, making it suitable for precision low-voltage reference applications where tight regulation is required.
What is the Zener impedance of the 1N5221B and why does it matter?
The 1N5221B exhibits a Zener impedance (ZZT) of 30 Ω at its 20 mA test current. This value reflects the dynamic resistance in the breakdown region-lower impedance means less output voltage variation under changing load current, directly improving regulation stability in power supply feedback paths and reference circuits.
Can the 1N5221B be used in high-temperature environments?
Yes, the 1N5221B is rated for continuous operation from −65 °C to +175 °C and maintains specified electrical performance across that full range. Its DO-35 glass package and internal construction support reliability in under-hood automotive, downhole oil/gas, and industrial motor control applications where ambient temperatures exceed 125 °C.
Is the 1N5221B RoHS compliant?
Yes-RoHS-compliant versions of the 1N5221B are available with the "e3" suffix (e.g., 1N5221Be3), featuring annealed matte-tin plating per MIL-STD-750 Method 2026. Standard versions use tin-lead plating; the e3 variant replaces lead with compliant materials without altering electrical or thermal specifications.
How does the temperature coefficient affect the 1N5221B's performance?
The 1N5221B has a temperature coefficient (αVZ) of −0.085 %/°C, meaning its Zener voltage decreases by approximately 2.04 mV per °C rise from 25 °C. This predictable drift allows designers to compensate in multi-Zener reference strings or select operating points where TC-induced error remains within system accuracy budgets.
1N5221B Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- DO-204AH, DO-35, Axial
- Packaging:
- Bulk
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 2.4 V
- Tolerance:
- ±5%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 30 Ohms
- Current - Reverse Leakage @ Vr:
- 100 µA @ 1 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.5 V @ 200 mA
- Operating Temperature:
- -65°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-204AH (DO-35)
1N5221B FAQ
1.How can I place an order for 1N5221B through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N5221B 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 1N5221B reliable?
The price and inventory of 1N5221B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5221B is usually 5 days.
3.What payment methods are accepted for 1N5221B?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5221B transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N5221B?
1N5221B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N5221B 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 1N5221B?
For technical support, including 1N5221B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5221B requirements.
6.How does Aetrix verify that 1N5221B is sourced from the original manufacturer or authorized distributors?
All 1N5221B 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 1N5221B meets industry standards.
7.What is the process for return or replacement of 1N5221B?
All 1N5221B units undergo pre-shipment inspection (PSI). If there is an issue with 1N5221B, 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 1N5221B part is unused and in its original packaging.
Return procedure for 1N5221B:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N5221B 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
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