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Microchip Technology 1N5249A
- Part No.:
- 1N5249A
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-204AH, DO-35, Axial
- Datasheet:
-
1N5249A.pdf
- Description:
- DIODE ZENER 19V 500MW DO204AH
- Quantity:
- Payment:
- Shipping:
Inventory:4,269
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Product details
Overview
1N5249A from Microsemi is a 19 V, ±10% tolerance, 500 mW glass axial-lead Zener diode in DO-35 (DO-204AH) package, rated for 6.6 mA test current, 600 Ω dynamic impedance at IZK, and 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 loops, and overvoltage protection.
For engineers reviewing the 1N5249A datasheet, 1N5249A pinout, 1N5249A application, or 1N5249A equivalent, key selection criteria include its 19 V nominal Zener voltage, 10% tolerance (A suffix), 600 Ω Zener impedance at 0.25 mA, temperature coefficient of +0.086 %/°C, and DO-35 mechanical compatibility with axial-leaded PCB layouts.
Technical Context
This discrete Zener diode operates in reverse breakdown to maintain stable voltage across its terminals under varying load and temperature conditions. Its regulation relies on controlled avalanche and Zener mechanisms, with specified performance at IZT = 6.6 mA and IZK = 0.25 mA.
The device exhibits a positive temperature coefficient (+0.086 %/°C), indicating increasing VZ with rising junction temperature - critical for thermal drift compensation in reference designs. Its 250 °C/W junction-to-lead thermal resistance supports reliable operation at 500 mW up to 50 °C lead temperature.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Zener Voltage | 19 V @ 6.6 mA test current - defines primary regulation point in shunt configuration |
| Zener Tolerance | ±10% (A suffix) - sets absolute voltage window: 17.1 V to 20.9 V at 25 °C |
| Power Dissipation | 500 mW at 25 °C, derated linearly above 50 °C lead temp - limits continuous current to ~26 mA at 19 V |
| Zener Impedance | 600 Ω @ IZK = 0.25 mA - determines regulation stiffness near knee; higher than at IZT |
| Temp Coefficient αVZ | +0.086 %/°C - quantifies VZ increase per degree rise; used to predict drift in wide-temp environments |
| Max Reverse Current | 10 μA @ VR = 14.3 V - defines leakage threshold before significant conduction begins |
| Forward Voltage | ≤1.5 V @ 200 mA - ensures predictable forward conduction if accidentally biased |
Pinout & Package
DO-35 (DO-204AH) hermetically sealed glass axial-lead 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 | Reverse-biased reference terminal | Connected to lower potential node; current flows into cathode during regulation |
| Cathode | Zener voltage output terminal | Banded end; held at stable 19 V relative to anode when reverse-biased above VZ |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC-registered DO-35 package | Industry-standard axial footprint enabling direct replacement and legacy board compatibility |
| −65 °C to +175 °C operating range | Supports deployment in aerospace, downhole, and industrial environments without derating penalties |
| Nonsensitive to ESD (MIL-STD-750 Method 1020) | Eliminates need for handling precautions or input protection circuitry during assembly |
| Inherently radiation hard | Validated per MicroNote 050 - suitable for low-dose-rate space or nuclear instrumentation applications |
| Minimal capacitance | Typical <2 pF - preserves high-frequency stability in RF biasing and fast transient suppression |
Applications
| Power Supply Feedback | Overvoltage Clamp |
|---|---|
Use Scenario: Regulating output voltage in discrete linear regulators or TL431-based feedback networks. IC Role / Device Role / Timing Role: Shunt reference element providing precise 19 V setpoint for error amplifier comparison. Use Value: Enables stable 19 V output with ±10% initial accuracy and predictable thermal drift (+0.086 %/°C). |
Use Scenario: Protecting microcontroller I/O pins or sensor inputs from transient overvoltage events. IC Role / Device Role / Timing Role: Clamping voltage to 19 V by conducting excess current when input exceeds VZ. Use Value: Limits peak voltage to ≤20.9 V (max) while dissipating up to 500 mW without failure. |
| Voltage Reference | Current Source Bias |
Use Scenario: Generating stable bias for op-amp comparators or analog front-end calibration circuits. IC Role / Device Role / Timing Role: Providing fixed 19 V reference against which other signals are measured or scaled. Use Value: Delivers low-drift reference with 600 Ω dynamic impedance ensuring minimal loading error at low currents. |
Use Scenario: Setting constant current in LED driver or transistor bias networks using series resistor + Zener. IC Role / Device Role / Timing Role: Maintaining fixed voltage drop to establish predictable emitter/base bias current. Use Value: Supports accurate current setting within ±10% tolerance and stable operation across −65 °C to +175 °C. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4742A (ON Semiconductor) | 12 V nominal, ±5% tolerance, 1 W power rating, DO-41 package | Higher power and tighter tolerance but different voltage and larger package | Select when 12 V regulation and 1 W dissipation are required; not a drop-in replacement due to voltage and footprint mismatch |
| BZX55-C19 (Vishay) | 19 V nominal, ±5% tolerance (C suffix), 500 mW, DO-35 package, same pinout | Same voltage and package, but tighter 5% tolerance and slightly lower Zener impedance (500 Ω typical) | Choose for improved initial accuracy and lower dynamic impedance where tighter regulation is critical |
Compared with 1N5249A, BZX55-C19 offers superior voltage accuracy and lower impedance in identical DO-35 packaging, while 1N4742A provides higher power at a different voltage - neither is pin-compatible with 1N5249A unless board layout accommodates DO-41 or voltage re-engineering is acceptable.
Availability
1N5249A is available at Aetrix Electronics and suitable for power supply feedback, overvoltage clamp, and voltage reference applications requiring stable component supply, long-term obsolescence resilience, and extended temperature support.
Supply support for 1N5249A 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 high-temperature analog and mixed-signal components.
The 1N52xxA/B series was designed for military, aerospace, and industrial applications demanding robust voltage regulation under extreme environmental stress and long service life.
FAQ
What is the nominal Zener voltage and tolerance of the 1N5249A?
The 1N5249A has a nominal Zener voltage of 19 V with a tolerance of ±10%, as indicated by the "A" suffix. This means its actual breakdown voltage falls between 17.1 V and 20.9 V at 25 °C and 6.6 mA test current. The tolerance is guaranteed per JEDEC specification for this part number, and the device is not rated for tighter tolerances unless marked with C (±2%) or D (±1%) suffixes.
What package type does the 1N5249A use, and how is polarity identified?
The 1N5249A uses the DO-35 (DO-204AH) glass axial-lead package. Polarity is identified by a single color band on the cathode end; the banded terminal must be held positive relative to the anode for proper Zener regulation. This marking aligns with JEDEC standard orientation and ensures correct placement during manual or automated assembly.
What is the maximum power dissipation and thermal derating behavior of the 1N5249A?
The 1N5249A is rated for 500 mW at 25 °C lead temperature, with linear derating beginning at 50 °C - reducing to zero at 175 °C. Its junction-to-lead thermal resistance is 250 °C/W at 3/8″ (10 mm) lead length. When mounted on FR4 with specified copper pads, junction-to-ambient resistance rises to 310 °C/W, limiting practical dissipation to ~480 mW at 25 °C ambient.
How does the temperature coefficient affect the 1N5249A's regulation voltage?
The 1N5249A has a positive temperature coefficient of +0.086 %/°C, meaning its Zener voltage increases by approximately 16.3 mV per °C rise in junction temperature. At 125 °C, VZ may reach ~19.9 V - a critical factor in high-temperature designs where regulation stability must be modeled across the full −65 °C to +175 °C operating range.
Is the 1N5249A suitable for high-reliability or radiation-exposed environments?
Yes - the 1N5249A is inherently radiation hard per MicroNote 050 and qualified for military screening levels (JAN, JANTX, JANTXV, JANS) when ordered with appropriate prefixes and "-1" suffix. Its glass DO-35 construction, ESD insensitivity (MIL-STD-750 Method 1020), and wide temperature range make it suitable for aerospace, downhole, and nuclear instrumentation applications.
1N5249A 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):
- 19 V
- Tolerance:
- ±10%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 23 Ohms
- Current - Reverse Leakage @ Vr:
- 100 nA @ 14 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)
1N5249A FAQ
1.How can I place an order for 1N5249A through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N5249A 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 1N5249A reliable?
The price and inventory of 1N5249A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5249A is usually 5 days.
3.What payment methods are accepted for 1N5249A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5249A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N5249A?
1N5249A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N5249A 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 1N5249A?
For technical support, including 1N5249A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5249A requirements.
6.How does Aetrix verify that 1N5249A is sourced from the original manufacturer or authorized distributors?
All 1N5249A 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 1N5249A meets industry standards.
7.What is the process for return or replacement of 1N5249A?
All 1N5249A units undergo pre-shipment inspection (PSI). If there is an issue with 1N5249A, 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 1N5249A part is unused and in its original packaging.
Return procedure for 1N5249A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N5249A Tags
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