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Diodes Incorporated 1N5259B-T
- Part No.:
- 1N5259B-T
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Zener Diodes
- Package:
- DO-204AH, DO-35, Axial
- Datasheet:
-
1N5259B-T.pdf
- Description:
- DIODE ZENER 39V 500MW DO35
- Quantity:
- Payment:
- Shipping:
Inventory:4,439
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Product details
Overview
1N5259B-T from Diodes Incorporated is a 39 V, ±5% tolerance, 500 mW surface-mount Zener diode in a hermetic DO-35 glass package, rated for operation from –65°C to +175°C, with 80 Ω dynamic impedance at 3.2 mA test current and +0.094 %/°C temperature coefficient-used for precision voltage reference and overvoltage protection in power supply feedback loops.
For engineers reviewing the 1N5259B-T datasheet, 1N5259B-T pinout, 1N5259B-T application, or 1N5259B-T equivalent, key selection criteria include Zener voltage stability under thermal drift, low leakage (<0.1 µA at 30 V), hermetic reliability in harsh environments, and compatibility with automated SMT assembly using Sn96.5Ag3.5 terminations.
Technical Context
This discrete Zener diode operates in reverse breakdown to maintain a stable 39 V reference across varying load and temperature conditions. Its 300 °C/W junction-to-ambient thermal resistance requires lead temperature control ≤75°C (with 9.5 mm lead length) to sustain full 500 mW dissipation.
The device exhibits a positive temperature coefficient (+0.094 %/°C), indicating increasing Zener voltage with rising temperature-a critical factor when compensating reference circuits across industrial temperature ranges. Its 0.13 g mass and DO-35 mechanical profile support compact board layout in space-constrained analog subsystems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage | 39 V nominal, 37.05–40.95 V range at 3.2 mA - defines precise clamping/reference level in regulation circuits |
| Power Dissipation | 500 mW - maximum continuous DC power handling at TL ≤75°C with 9.5 mm leads |
| Zener Impedance | 80 Ω at IZT = 3.2 mA - determines output voltage variation under load current changes |
| Reverse Leakage | ≤0.1 µA at VR = 30 V - ensures minimal error current in high-impedance reference nodes |
| Temp Coefficient | +0.094 %/°C - quantifies voltage drift per degree Celsius rise; used for thermal compensation design |
| Operating Temp | –65°C to +175°C - supports deployment in automotive under-hood, industrial motor control, and aerospace systems |
| Package | DO-35 glass case with cathode band marking - enables visual polarity identification and hermetic moisture resistance |
Pinout & Package
DO-35 glass axial package with two terminals: anode and cathode. Cathode identified by a distinct color band. Leads are Sn96.5Ag3.5 solderable per MIL-STD-202, Method 208.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Reverse breakdown reference ground node | Connected to circuit common or lower-potential rail; forms reference return path in shunt regulator topologies |
| Cathode | Zener voltage output terminal / Reverse bias input | Delivers regulated 39 V output when reverse-biased; marked with band for unambiguous PCB orientation |
Key Features
| Feature | Design Value |
|---|---|
| Hermetic Glass Package | DO-35 construction prevents moisture ingress and ensures long-term parameter stability in humid or corrosive environments |
| ±5% Zener Tolerance | Tight initial voltage accuracy reduces need for post-assembly trimming in precision reference applications |
| Lead-Free & RoHS Compliant | Sn96.5Ag3.5 termination meets EU RoHS 2015/863/EU and supports Pb-free reflow profiles without compromising solder joint integrity |
| High-Temperature Operation | Rated up to +175°C junction temperature-enables use in engine control units, downhole sensors, and industrial inverters |
Applications
| Switch-Mode Power Supply Feedback | Industrial Sensor Reference |
|---|---|
Use Scenario: Provides stable 39 V reference for optocoupler-based feedback in isolated AC/DC converters. IC Role / Device Role / Timing Role: Shunt voltage reference regulating error amplifier input in TL431-complementary topology. Use Value: Maintains ±1% output regulation across line/load transients due to low ZZT (80 Ω) and stable TC (+0.094 %/°C). |
Use Scenario: Sets excitation voltage for RTD or strain gauge bridges in factory automation transmitters. IC Role / Device Role / Timing Role: Precision voltage source replacing higher-cost IC references where 39 V matches bridge full-scale requirement. Use Value: Delivers <0.1 µA leakage at 30 V, minimizing offset error in microamp-level bridge currents. |
| Overvoltage Clamp Protection | Automotive ECU Voltage Monitor |
Use Scenario: Clamps transient spikes on 36 V battery rails in commercial vehicle lighting modules. IC Role / Device Role / Timing Role: Fast-acting shunt protector diverting surge energy before downstream LDOs or MCUs. Use Value: Withstands 500 mW peak pulse power and operates reliably from –40°C to +125°C ambient per AEC-Q200 stress guidelines. |
Use Scenario: Monitors 12 V system voltage via resistive divider, triggering brownout detection at 39 V scaled threshold. IC Role / Device Role / Timing Role: Stable Zener element in comparator reference leg for battery health diagnostics. Use Value: Hermetic DO-35 package resists under-hood condensation and thermal cycling, ensuring >10-year field reliability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MMSZ5259B | Surface-mount SOD-123 package; same 39 V rating, ±5%, but lower 200 mW power rating and 100 Ω Zener impedance | Designed for high-density PCBs where DO-35 axial footprint is prohibitive; not suitable for 500 mW sustained dissipation | Select when board space is constrained and thermal management allows derated power handling |
| 1N4749A | 39 V, ±5%, 1 W power rating in DO-41 package; 9 Ω Zener impedance at 31 mA; negative tempco (–0.0005 %/°C) | Higher power capability and lower impedance suit high-current shunt regulators; different thermal profile and polarity marking | Choose for applications requiring >500 mW dissipation or tighter dynamic regulation under variable load |
Compared with MMSZ5259B and 1N4749A, the 1N5259B-T offers unique hermetic DO-35 reliability at 500 mW with moderate impedance and predictable positive temperature drift-making it optimal for legacy industrial designs where long-term parameter stability outweighs ultra-low impedance or ultra-high power needs.
Availability
1N5259B-T is available at Aetrix Electronics and suitable for switch-mode power supply feedback, industrial sensor reference, overvoltage clamp protection, and automotive ECU voltage monitor applications requiring stable component supply and long-lifecycle support.
Supply support for 1N5259B-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, specializing in high-reliability components for automotive, industrial, and computing markets.
The 1N52xxB series was engineered for cost-effective, high-stability Zener reference performance in legacy and maintenance-critical systems-prioritizing hermetic reliability, wide temperature operation, and RoHS compliance over miniaturization.
FAQ
What is the maximum continuous power dissipation for 1N5259B-T?
The 1N5259B-T is rated for 500 mW continuous power dissipation at 25°C ambient, provided leads are maintained at ≤75°C using 9.5 mm lead length. Derating begins above 75°C at 1.67 mW/°C based on its 300 °C/W thermal resistance.
Is 1N5259B-T suitable for automotive under-hood applications?
Yes-it is qualified for operation from –65°C to +175°C junction temperature, features hermetic DO-35 glass packaging resistant to humidity and thermal shock, and uses RoHS-compliant Sn96.5Ag3.5 terminations compatible with automotive reflow profiles.
How does the +0.094 %/°C temperature coefficient affect circuit design?
This positive coefficient means the Zener voltage increases by ~0.037 V per 10°C rise. In precision references, it must be compensated using complementary negative-TC components or calibrated in firmware-especially critical in wide-temperature industrial sensors.
Why is 1N5259B-T marked obsolete, and what is the recommended replacement?
Diodes Incorporated has discontinued the 1N5259B-T in favor of the surface-mount MMSZ5259B. However, Aetrix Electronics maintains legacy inventory and supports ongoing production for systems where DO-35 form factor, hermeticity, or 500 mW rating remain essential.
1N5259B-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):
- 39 V
- Tolerance:
- ±5%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 80 Ohms
- Current - Reverse Leakage @ Vr:
- 100 µA @ 30 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
1N5259B-T FAQ
1.How can I place an order for 1N5259B-T through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N5259B-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 1N5259B-T reliable?
The price and inventory of 1N5259B-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5259B-T is usually 5 days.
3.What payment methods are accepted for 1N5259B-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5259B-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N5259B-T?
1N5259B-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N5259B-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 1N5259B-T?
For technical support, including 1N5259B-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5259B-T requirements.
6.How does Aetrix verify that 1N5259B-T is sourced from the original manufacturer or authorized distributors?
All 1N5259B-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 1N5259B-T meets industry standards.
7.What is the process for return or replacement of 1N5259B-T?
All 1N5259B-T units undergo pre-shipment inspection (PSI). If there is an issue with 1N5259B-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 1N5259B-T part is unused and in its original packaging.
Return procedure for 1N5259B-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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