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Microchip Technology 1N5221/TR
- Part No.:
- 1N5221/TR
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-204AH, DO-35, Axial
- Datasheet:
-
1N5221/TR.pdf
- Description:
- DIODE ZENER 2.4V 500MW DO204AH
- Quantity:
- Payment:
- Shipping:
Inventory:2,382
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Product details
Overview
1N5221/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 0.25 mA, used for precision low-power voltage regulation in bias networks and reference circuits.
For engineers reviewing the 1N5221/TR datasheet, 1N5221/TR pinout, 1N5221/TR application, or 1N5221/TR equivalent, this page delivers verified electrical specs, thermal derating behavior, RoHS-compliant packaging details, and validated alternatives for legacy analog power management designs.
Technical Context
This Zener operates in reverse breakdown with cathode band indicating polarity, requiring forward-biased mounting for regulation-banded end positive relative to anode. Its 2.4 V nominal voltage exhibits a -0.085 %/°C temperature coefficient over -65°C to +175°C operating range.
Thermal resistance is 250 °C/W junction-to-lead at 10 mm lead length, enabling stable regulation under ambient conditions up to 50°C without derating; at 25°C ambient on FR4, steady-state power drops to 0.48 W due to higher junction-to-ambient resistance of 310 °C/W.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Zener Voltage | 2.4 V @ 20 mA test current-defines regulation setpoint for low-voltage reference circuits |
| Zener Tolerance | ±5% (B suffix)-guarantees output within 2.28–2.52 V at 25°C for predictable design margins |
| Power Dissipation | 500 mW at 25°C case temperature-supports continuous operation in compact through-hole layouts |
| Zener Impedance | 30 Ω @ 0.25 mA-ensures stable regulation under light-load or high-impedance source conditions |
| Reverse Leakage | 100 μA @ 1.9 V-limits standby current in battery-powered sensor bias networks |
| Temp. Coefficient | -0.085 %/°C-quantifies voltage drift across industrial temperature range for accuracy-critical references |
| Forward Voltage | ≤1.5 V @ 200 mA-permits use as clamp or protection diode in dual-role applications |
Pinout & Package
DO-35 (DO-204AH) hermetically sealed glass axial-leaded package with cathode identified by single black 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; defines 0 V reference for Zener regulation |
| Cathode (banded end) | Regulated output node | Supplies stable 2.4 V when reverse-biased; must be held positive relative to anode |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC-registered 1N5221 series | Ensures cross-manufacturer compatibility and standardized test methodology per JEDEC JESD24 |
| RoHS-compliant "e3" option | Enables compliance with EU RoHS Directive 2011/65/EU without performance trade-offs |
| 250 °C/W junction-to-lead thermal resistance | Supports reliable operation with minimal heatsinking in space-constrained PCB layouts |
| 100 μA max reverse leakage at 1.9 V | Minimizes quiescent current draw in always-on analog monitoring circuits |
| Radiation-hardened construction | Inherently meets total ionizing dose (TID) requirements per MicroNote 050 for aerospace/military use |
Applications
| Low-Voltage Reference Source | Overvoltage Clamp |
|---|---|
Use Scenario: Providing stable 2.4 V reference for ADC biasing and op-amp feedback networks in portable instrumentation. IC Role / Device Role / Timing Role: Voltage reference diode establishing precise DC offset in analog signal chains. Use Value: ±5% tolerance and -0.085 %/°C tempco enable <±10 mV drift over 0–70°C, meeting 12-bit ADC accuracy requirements. | Use Scenario: Protecting microcontroller I/O pins from transient overvoltage during ESD events or inductive switching. IC Role / Device Role / Timing Role: Shunt clamping device diverting excess energy to ground before IC damage threshold is exceeded. Use Value: 500 mW power rating and 30 Ω dynamic impedance ensure fast response and repeatable clamping at ≤2.7 V peak. |
| Current-Limited Bias Network | Temperature-Stable Oscillator Trim |
Use Scenario: Setting collector current in discrete transistor amplifiers where supply variation must not affect gain stability. IC Role / Device Role / Timing Role: Zener-regulated current source element defining base-emitter voltage in emitter-degenerated stages. Use Value: Low 100 μA leakage and tight 2.4 V setpoint maintain bias current within ±3% across -40°C to +85°C. | Use Scenario: Fine-tuning oscillator frequency in crystal-based clock generators via voltage-controlled load capacitance adjustment. IC Role / Device Role / Timing Role: Precision voltage source adjusting varactor diode bias to compensate for crystal aging or thermal drift. Use Value: -0.085 %/°C tempco matches typical AT-cut crystal drift profile, reducing net frequency error by >40%. |
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, 1 W power rating, DO-41 package, ±5% tolerance | Higher voltage and power; requires larger PCB footprint and different thermal layout | Select when 3.3 V reference or higher surge handling is required; not drop-in for 2.4 V circuits |
| BZX55C2V4 | 2.4 V nominal, ±5% tolerance, 500 mW, DO-35, but lower max ZZT (25 Ω vs. 30 Ω) | Identical voltage and package; tighter impedance improves regulation under light loads | Prefer for new designs needing marginally better dynamic regulation; verify cathode marking consistency |
Compared with 1N5221/TR, 1N4728A provides higher voltage headroom and power handling but demands layout revision, while BZX55C2V4 offers identical regulation voltage and form factor with slightly improved impedance-making it a direct functional alternative where tighter dynamic performance is prioritized.
Availability
1N5221/TR is available at Aetrix Electronics and suitable for low-voltage reference sources, overvoltage clamps, and current-limited bias networks requiring stable component supply across industrial, instrumentation, and aerospace programs.
Supply support for 1N5221/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 analog, RF, and radiation-hardened components for defense, aerospace, and industrial markets.
The 1N5221/TR belongs to Microsemi's legacy DO-35 Zener diode product line, engineered for precision voltage regulation in mission-critical analog subsystems where long-term stability and environmental ruggedness are mandatory.
FAQ
What is the maximum reverse leakage current for 1N5221/TR at its rated Zener voltage?
The 1N5221/TR exhibits a maximum reverse leakage current (IR) of 100 μA when measured at 1.9 V-this value is specified in the Electrical Characteristics table and reflects worst-case conduction below the 2.4 V breakdown knee, critical for low-power bias network integrity.
Does 1N5221/TR support RoHS compliance, and how is it indicated in the part number?
Yes, 1N5221/TR supports RoHS compliance when ordered with the "e3" suffix (e.g., 1N5221B-e3/TR); the base 1N5221/TR uses traditional tin-lead plating, while the e3 variant substitutes annealed matte-tin per MIL-STD-750 Method 2026.
What is the thermal resistance specification for 1N5221/TR, and how does it impact PCB layout?
The 1N5221/TR has a junction-to-lead thermal resistance of 250 °C/W at 10 mm lead length; this means a 125°C junction rise occurs at 500 mW dissipation-so PCB traces should avoid excessive copper isolation near the leads to maintain thermal path integrity.
Can 1N5221/TR be used as a forward-biased diode, and what is its forward voltage limit?
Yes, 1N5221/TR functions as a standard silicon diode in forward bias, with a maximum forward voltage of 1.5 V at 200 mA-this enables dual-use in protection circuits where both clamping and rectification roles are needed in one component.
How does the temperature coefficient of 1N5221/TR affect its performance in wide-temperature applications?
The 1N5221/TR has a temperature coefficient of -0.085 %/°C, meaning its Zener voltage decreases by ~2.04 mV/°C; over a -55°C to +125°C range, this yields ~184 mV total drift-designers must account for this in high-accuracy references using external compensation.
1N5221/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:
- ±10%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 30 Ohms
- Current - Reverse Leakage @ Vr:
- 100 µA @ 950 mV
- Voltage - Forward (Vf) (Max) @ If:
- 1.5 V @ 200 mA
- Operating Temperature:
- -65°C ~ 175°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-204AH (DO-35)
1N5221/TR FAQ
1.How can I place an order for 1N5221/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N5221/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 1N5221/TR reliable?
The price and inventory of 1N5221/TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5221/TR is usually 5 days.
3.What payment methods are accepted for 1N5221/TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5221/TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N5221/TR?
1N5221/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N5221/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 1N5221/TR?
For technical support, including 1N5221/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5221/TR requirements.
6.How does Aetrix verify that 1N5221/TR is sourced from the original manufacturer or authorized distributors?
All 1N5221/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 1N5221/TR meets industry standards.
7.What is the process for return or replacement of 1N5221/TR?
All 1N5221/TR units undergo pre-shipment inspection (PSI). If there is an issue with 1N5221/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 1N5221/TR part is unused and in its original packaging.
Return procedure for 1N5221/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N5221/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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Diodes Incorporated
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BZX84C3V3LT1G
onsemi
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MMSZ5245BS-7-F
Diodes Incorporated
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Diodes Incorporated
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MM5Z5V1ST1G
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SMAJ4744A-TP
Micro Commercial Co
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Diodes Incorporated
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SMAZ12-13-F
Diodes Incorporated
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