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Microchip Technology 1N5221B/TR
- Part No.:
- 1N5221B/TR
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-204AH, DO-35, Axial
- Datasheet:
-
1N5221B/TR.pdf
- Description:
- DIODE ZENER 2.4V 500MW DO204AH
- Quantity:
- Payment:
- Shipping:
Inventory:5,979
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Product details
Overview
1N5221B/TR 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 IZK, operating from −65 °C to +175 °C. It serves as a precision voltage reference or shunt regulator in low-power analog circuits, power supply feedback paths, and overvoltage protection.
For engineers reviewing the 1N5221B/TR datasheet, 1N5221B/TR pinout, 1N5221B/TR application, or 1N5221B/TR equivalent, this page delivers verified electrical specs, thermal derating behavior, Zener temperature coefficient (−0.085 %/°C), RoHS-compliant plating options, and tape-and-reel packaging details per EIA-296.
Technical Context
This discrete Zener diode operates in reverse breakdown with cathode-banded polarity, requiring the banded end to be held positive relative to the anode for regulation. Its 2.4 V nominal Zener voltage is specified at 20 mA test current (IZT), with 30 Ω dynamic impedance measured at 0.25 mA (ZZK) and 1200 Ω at IZK.
Thermal resistance is 250 °C/W junction-to-lead (3/8″ lead length) and 310 °C/W junction-to-ambient on FR4 with defined copper layout. Forward voltage is ≤1.5 V at 200 mA, and it exhibits minimal capacitance per Figure 2 - critical for high-frequency stability in reference and clamping roles.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Zener Voltage (VZ) | 2.4 V @ 20 mA - defines stable regulation point for low-voltage reference design |
| Zener Tolerance | ±5% (B suffix) - ensures predictable voltage window without post-selection |
| Power Dissipation | 500 mW at 25 °C - sets maximum continuous DC power before thermal derating applies |
| Zener Impedance (ZZT) | 30 Ω @ IZK = 0.25 mA - indicates sharp knee and low AC impedance near regulation threshold |
| Temperature Coefficient (αVZ) | −0.085 %/°C - quantifies voltage drift over temperature; negative sign confirms decreasing VZ with rising T |
| Max Reverse Current (IR) | 100 μA @ 1.0 V - defines leakage ceiling below breakdown, critical for standby power integrity |
| Operating Temperature | −65 °C to +175 °C - supports aerospace, downhole, and industrial environments without derating |
Pinout & Package
DO-35 (DO-204AH) hermetically sealed glass axial-lead package with tin-lead or RoHS-compliant matte-tin plating. Cathode identified by color band; device operated with banded end positive for Zener regulation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (unbanded end) | Reference ground node | Connected to circuit common; forms return path for Zener current during regulation |
| Cathode (banded end) | Regulated output node | Held at stable 2.4 V above anode; supplies reference voltage or clamps overvoltage |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC-registered 1N5221B | Guarantees compliance with industry-standard mechanical and electrical limits for 2.4 V Zeners |
| RoHS-compliant option (e3 suffix) | Enables use in environmentally regulated industrial and medical designs without lead exemption |
| Nonsensitive to ESD (MIL-STD-750 Method 1020) | Eliminates need for external ESD protection in handling and board-level assembly |
| Inherently radiation-hardened | Validated per MicroNote 050 - suitable for space-qualified and nuclear instrumentation applications |
| Tape-and-reel packaging (TR suffix) | Supports automated SMT placement despite axial-leaded form factor via carrier tape compatibility |
Applications
| Industrial Power Monitoring | Low-Voltage Reference Circuit |
|---|---|
Use Scenario: Monitoring 3.3 V rail in PLC I/O modules using resistor-divider + comparator. IC Role / Device Role / Timing Role: Shunt reference providing stable 2.4 V threshold against which divided rail voltage is compared. Use Value: Enables accurate trip-point detection across −40 °C to +85 °C ambient with <±0.2 V total drift due to known αVZ and tight ±5% initial tolerance. |
Use Scenario: Biasing op-amp input stage in battery-powered sensor signal conditioning. IC Role / Device Role / Timing Role: Low-power voltage reference generating precise 2.4 V for ADC reference or amplifier offset nulling. Use Value: Delivers sub-100 μA quiescent current draw and 30 Ω dynamic impedance - minimizing load-induced error in high-impedance analog nodes. |
| Overvoltage Clamp Protection | Aerospace Sensor Interface |
Use Scenario: Protecting microcontroller GPIO pins from transient surges on 3.3 V data lines. IC Role / Device Role / Timing Role: Fast-acting shunt clamp limiting voltage to 2.4 V + forward drop during ESD events. Use Value: Leverages low capacitance (per Figure 2) and −65 °C to +175 °C operation to maintain clamping integrity in automotive under-hood environments. |
Use Scenario: Providing bias voltage for radiation-tolerant pressure transducers in satellite telemetry systems. IC Role / Device Role / Timing Role: Radiation-hardened Zener reference ensuring long-term voltage stability in single-event upset (SEU)-prone orbits. Use Value: Inherent radiation hardness per MicroNote 050 eliminates need for shielding or redundancy - reducing SWaP-C in payload electronics. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4728A | 3.3 V nominal, ±5%, DO-41 package, 1.0 W rating, 10 Ω ZZT | Higher power and voltage; larger DO-41 footprint; not radiation-hardened | Select when higher power dissipation (>500 mW) or tighter ZZT is required, and radiation tolerance is not needed. |
| BZX55C2V4 | 2.4 V nominal, ±5%, DO-35 package, 500 mW, 60 Ω ZZT, no radiation hardening | Same package and voltage but higher dynamic impedance and no inherent radiation tolerance | Choose for cost-sensitive commercial applications where radiation performance and ultra-low ZZT are non-critical. |
Compared with 1N5221B/TR, 1N4728A offers higher power and lower impedance but lacks radiation hardness and uses a larger package; BZX55C2V4 matches voltage and package but trades off impedance and radiation resilience for lower cost.
Availability
1N5221B/TR is available at Aetrix Electronics and suitable for industrial power monitoring, low-voltage reference circuits, overvoltage clamp protection, and aerospace sensor interface applications requiring stable component supply across extended temperature and radiation environments.
Supply support for 1N5221B/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-tolerant, and high-temperature analog and mixed-signal components.
The 1N5221B/TR belongs to Microsemi's legacy 1N52xxB Zener series - engineered for precision voltage regulation in mission-critical aerospace, defense, and industrial systems where thermal stability and radiation immunity are mandatory.
FAQ
What is the Zener voltage tolerance of the 1N5221B/TR?
The 1N5221B/TR has a nominal Zener voltage of 2.4 V with a guaranteed tolerance of ±5%, indicated by the "B" suffix per JEDEC specification. This tolerance is validated across the full operating temperature range of −65 °C to +175 °C and applies to devices tested at 20 mA Zener test current (IZT).
Does the 1N5221B/TR require external ESD protection?
No - the 1N5221B/TR is nonsensitive to ESD per MIL-STD-750 Method 1020, meaning it withstands standard handling and board-level ESD events without degradation. This eliminates the need for additional TVS diodes or layout-level ESD mitigation when using the 1N5221B/TR in sensitive analog reference paths.
What is the thermal resistance of the 1N5221B/TR in typical PCB mounting?
When mounted on an FR4 PCB with 1 oz copper, 4 mm² pads, and 1 mm wide × 25 mm long traces, the 1N5221B/TR exhibits a junction-to-ambient thermal resistance of 310 °C/W. This value directly informs derating curves: power must be reduced linearly above 50 °C lead temperature or 25 °C ambient, per Figure 1 in the official datasheet.
Is the 1N5221B/TR available in RoHS-compliant form?
Yes - the 1N5221B/TR can be supplied with RoHS-compliant annealed matte-tin plating, designated by the "e3" suffix (e.g., 1N5221B-e3/TR). This version meets EU RoHS Directive 2011/65/EU and is solderable per MIL-STD-750 Method 2026, with identical electrical and thermal specifications as the tin-lead variant.
How does the temperature coefficient affect the 1N5221B/TR's regulation accuracy?
The 1N5221B/TR has a Zener voltage temperature coefficient (αVZ) of −0.085 %/°C, meaning its regulated voltage decreases by approximately 2.04 mV per °C rise from 25 °C. Over a −40 °C to +85 °C range, this yields ~255 mV total drift - a key design consideration when using the 1N5221B/TR in unbuffered reference applications.
1N5221B/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):
- 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/TR FAQ
1.How can I place an order for 1N5221B/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N5221B/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 1N5221B/TR reliable?
The price and inventory of 1N5221B/TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5221B/TR is usually 5 days.
3.What payment methods are accepted for 1N5221B/TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5221B/TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N5221B/TR?
1N5221B/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N5221B/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 1N5221B/TR?
For technical support, including 1N5221B/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5221B/TR requirements.
6.How does Aetrix verify that 1N5221B/TR is sourced from the original manufacturer or authorized distributors?
All 1N5221B/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 1N5221B/TR meets industry standards.
7.What is the process for return or replacement of 1N5221B/TR?
All 1N5221B/TR units undergo pre-shipment inspection (PSI). If there is an issue with 1N5221B/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 1N5221B/TR part is unused and in its original packaging.
Return procedure for 1N5221B/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N5221B/TR Tags
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MMBZ5240B-7-F
Diodes Incorporated
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BZT52C5V6T-7
Diodes Incorporated
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MMSZ5231B-7-F
Diodes Incorporated
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BZT52C15-7-F
Diodes Incorporated
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BZX84C3V3LT1G
onsemi
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MMSZ5245BS-7-F
Diodes Incorporated
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MMSZ4682T1G
onsemi
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BZT52C15S-7-F
Diodes Incorporated
-
MM5Z5V1ST1G
onsemi
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SMAJ4744A-TP
Micro Commercial Co
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BZT52C3V6LP-7
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SMAZ12-13-F
Diodes Incorporated
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