My Inquiry
My Account
Diodes Incorporated 1N5221B-T
- Part No.:
- 1N5221B-T
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Zener Diodes
- Package:
- DO-204AH, DO-35, Axial
- Datasheet:
-
1N5221B-T.pdf
- Description:
- DIODE ZENER 2.4V 500MW DO35
- Quantity:
- Payment:
- Shipping:
Inventory:3,633
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
1N5221B-T from Diodes Incorporated is a 2.4 V, ±5% tolerance, 500 mW surface-mount Zener diode in DO-35 glass package, rated for 20 mA test current and 30 Ω dynamic impedance at 20 mA, used for precision voltage reference and low-power regulation in analog sensor interfaces and power supply feedback loops.
For engineers reviewing the 1N5221B-T datasheet, 1N5221B-T pinout, 1N5221B-T application, or 1N5221B-T equivalent, key selection criteria include zener voltage accuracy (2.28–2.52 V), temperature coefficient (−0.085 %/°C), reverse leakage (100 µA at 1.0 V), thermal resistance (300 °C/W), and hermetic glass packaging for stable long-term operation.
Technical Context
This discrete Zener diode operates in reverse breakdown to maintain a stable 2.4 V reference with tight ±5% initial tolerance and low −0.085 %/°C temperature drift. Its 500 mW power rating and 300 °C/W junction-to-ambient thermal resistance require lead-length-controlled mounting (9.5 mm) to sustain full dissipation.
The device features a cathode band polarity marker, Sn96.5Ag3.5 solderable terminals per MIL-STD-202, and J-STD-020 Level 1 moisture sensitivity-enabling standard reflow assembly without baking. It is RoHS-compliant and halogen-free per Diodes Incorporated's green policy.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage | 2.4 V nominal (2.28–2.52 V range at 20 mA); enables precise low-voltage biasing in analog circuits |
| Power Dissipation | 500 mW maximum; requires lead length ≤9.5 mm and TL ≤75°C for full rating |
| Zener Impedance | 30 Ω at 20 mA; ensures minimal output voltage variation under load changes |
| Temp Coefficient | −0.085 %/°C; supports stable reference over −65°C to +175°C operating range |
| Reverse Leakage | 100 µA at 1.0 V; guarantees low quiescent current in standby regulation |
| Package | DO-35 glass case; hermetic seal provides long-term parameter stability and humidity immunity |
Pinout & Package
DO-35 glass axial package with cathode band marking; leads are Sn96.5Ag3.5 solderable per MIL-STD-202 Method 208; polarity identified by single black band on cathode end.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Zener cathode reference ground | Connected to circuit ground or lower-potential node in shunt regulator configuration |
| Cathode | Zener breakdown terminal / voltage reference output | Connected to input rail via series resistor; delivers regulated 2.4 V to load |
Key Features
| Feature | Design Value |
|---|---|
| Hermetic Glass Package | Ensures parametric stability over time and humidity exposure, critical for calibration-critical references |
| ±5% Zener Tolerance | Reduces need for post-production trimming in low-cost voltage reference designs |
| −0.085 %/°C Tempco | Minimizes drift-induced error in temperature-sensitive instrumentation front-ends |
| RoHS & Halogen-Free | Meets global environmental compliance requirements without sacrificing electrical performance |
Applications
| Industrial Sensor Signal Conditioning | Low-Power Microcontroller Reset Circuit |
|---|---|
Use Scenario: Providing stable 2.4 V reference for bridge sensor excitation and ADC biasing in factory-floor pressure transducers. IC Role / Device Role / Timing Role: Shunt voltage reference maintaining excitation voltage within ±0.1% across −40°C to +85°C ambient. Use Value: Enables <12-bit effective resolution without external trimming, leveraging tight initial tolerance and low tempco. | Use Scenario: Generating clean reset threshold for 3.3 V microcontrollers in battery-powered IoT edge nodes. IC Role / Device Role / Timing Role: Zener-based reset supervisor with hysteresis set by resistor divider off 2.4 V reference. Use Value: Delivers deterministic reset assertion at 2.4 V ±0.12 V, reducing false triggers during brown-out conditions. |
| Linear Regulator Feedback Divider | ESD-Protected Analog Input Clamp |
Use Scenario: Setting output voltage of adjustable LDOs (e.g., AP2112) via feedback network referencing 2.4 V node. IC Role / Device Role / Timing Role: Precision voltage node defining regulation setpoint independent of LDO internal reference. Use Value: Allows accurate 2.4 V output or programmable outputs using ratio-matched resistors, improving system-level accuracy. | Use Scenario: Clamping op-amp inputs to ±2.4 V in industrial data acquisition front-ends exposed to transient surges. IC Role / Device Role / Timing Role: Low-leakage bidirectional clamp (with series diode) limiting signal swing before amplification. Use Value: Maintains <100 µA leakage at 1.0 V, preserving high-impedance input integrity while surviving 8 kV HBM ESD events. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MMSZ5221B | Surface-mount SOD-123 package; same 2.4 V, ±5%, 500 mW rating; 30 Ω ZZT; −0.085 %/°C tempco | Replaces 1N5221B-T in automated PCB assembly; eliminates axial lead forming and manual placement | Select for new designs requiring SMT compatibility and higher board density |
| 1N4732A | 5.6 V nominal, 1 W rating, DO-41 package; ±5% tolerance; 5 Ω ZZT; +0.038 %/°C tempco | Higher power and voltage; unsuitable for 2.4 V circuits but preferred where higher headroom or lower impedance is needed | Choose only when redesigning for >5 V reference or >500 mW dissipation requirements |
Compared with MMSZ5221B, 1N5221B-T offers identical electrical specs but requires through-hole assembly and delivers superior long-term stability due to hermetic glass construction; versus 1N4732A, it provides lower voltage and tighter thermal drift but less power handling-making it optimal for precision low-voltage analog references.
Availability
1N5221B-T is available at Aetrix Electronics and suitable for industrial sensor conditioning, microcontroller reset generation, and linear regulator feedback requiring stable component supply despite its obsolete status-stock is maintained for legacy system support and repair programs.
Supply support for 1N5221B-T 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
Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design and manufacturing operations across Asia and the Americas.
The 1N52xxB series belongs to Diodes' legacy Zener diode product line, engineered for general-purpose voltage regulation and reference applications where reliability, consistency, and hermetic sealing are prioritized over miniaturization.
FAQ
Is 1N5221B-T still in active production?
No-1N5221B-T is officially obsolete and discontinued by Diodes Incorporated per DS18006 Rev. 19. However, Aetrix Electronics maintains limited legacy stock for repair, maintenance, and end-of-life system support with full traceability and documentation.
What is the maximum continuous reverse current at 25°C?
At 25°C ambient and 20 mA test current, the maximum reverse current (leakage) is 100 µA when reverse-biased at 1.0 V. At VR = 0.5 V, leakage drops to <1 µA; no derating is required below 75°C case temperature.
Can 1N5221B-T be used in reflow soldering processes?
No-it is a DO-35 glass axial device intended for wave soldering or hand-soldering. Its glass body and axial leads are not rated for standard SMT reflow profiles. For reflow-compatible alternatives, consider MMSZ5221B in SOD-123 package.
How does the −0.085 %/°C temperature coefficient affect regulation accuracy?
Over a 100°C span (−25°C to +75°C), the zener voltage shifts by −8.5 mV (0.085 %/°C × 2.4 V × 100°C), resulting in ±0.0085 V total drift. This enables sub-0.5% total regulation error in well-ventilated, non-heat-sinked PCB layouts.
1N5221B-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- DO-204AH, DO-35, Axial
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- 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:
- 1.1 V @ 200 mA
- Operating Temperature:
- -65°C ~ 200°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-35
1N5221B-T FAQ
1.How can I place an order for 1N5221B-T through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N5221B-T 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-T reliable?
The price and inventory of 1N5221B-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5221B-T is usually 5 days.
3.What payment methods are accepted for 1N5221B-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5221B-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N5221B-T?
1N5221B-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N5221B-T 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-T?
For technical support, including 1N5221B-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5221B-T requirements.
6.How does Aetrix verify that 1N5221B-T is sourced from the original manufacturer or authorized distributors?
All 1N5221B-T 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-T meets industry standards.
7.What is the process for return or replacement of 1N5221B-T?
All 1N5221B-T units undergo pre-shipment inspection (PSI). If there is an issue with 1N5221B-T, 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-T part is unused and in its original packaging.
Return procedure for 1N5221B-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N5221B-T 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
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…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
LDO regulator guide covering low dropout voltage, power dissipation, thermal design, PSRR, output noise, capacitor stability, adjustable LDO circuits, LDO vs buck converter and datasheet selection chec…
Conditional Access Module guide covering CAM meaning, CI/CI+ interface, smart card authorization, DVB security workflow, TV and set-top box compatibility, internal electronics, ESD protection, connecto…
Guide to electronic component obsolescence covering EOL risk, PCN/PDN notices, last-time buy planning, replacement options, form-fit-function validation, counterfeit risk and BOM lifecycle management.
18650 battery guide covering lithium-ion cell basics, 3.6V/3.7V voltage, 4.2V charging, mAh and Wh capacity, protected cells, chargers, BMS, series-parallel packs, holders, welding and sourcing checks.…
Hall effect sensor guide covering working principle, linear and digital sensors, Arduino circuits, current sensing, speed detection, automotive applications, A3144 examples, signal filtering and datash…
Product Change Notification guide for electronic components, covering PCN meaning, PCN vs PDN/EOL, common change types, risk levels, form-fit-function review, engineering validation, BOM control, LTB/L…
A practical guide to blend door actuators, covering HVAC function, symptoms, location, AC and heater issues, reset and calibration, replacement cost, electrical diagnosis, compatibility checks, and rep…
