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onsemi 1N5249B_T50A
- Part No.:
- 1N5249B_T50A
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- DO-204AH, DO-35, Axial
- Datasheet:
-
1N5249B_T50A.pdf
- Description:
- DIODE ZENER 19V 500MW DO35
- Quantity:
- Payment:
- Shipping:
Inventory:8,096
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Product details
Overview
1N5249B_T50A from ON Semiconductor is a 19 V ±5% Zener diode in DO-35 glass package, rated for 500 mW power dissipation at 25°C, with 23 Ω dynamic impedance at 19 mA test current and 0.1 μA reverse leakage at 15.2 V. It serves as a precision voltage reference or overvoltage clamp in low-power analog circuits.
For engineers reviewing the 1N5249B_T50A datasheet, pinout, applications, or equivalent options, key selection criteria include Zener voltage tolerance, thermal coefficient (+0.085 %/°C), junction temperature range (–65 to +200°C), and DO-35 mechanical compatibility with through-hole PCB layouts.
Technical Context
This device operates in reverse breakdown mode to maintain stable voltage across its terminals under varying load or supply conditions. Its 19 V nominal Zener voltage is specified at IZ = 19 mA, with guaranteed min/max bounds of 18.05 V and 19.95 V at 25°C.
The diode exhibits a positive temperature coefficient of +0.085 %/°C, indicating voltage increases with rising junction temperature - critical for biasing stability in temperature-sensitive references. It uses a hermetically sealed DO-35 glass package with cathode band marking and 0.137 g mass per JEDEC DO-204AH standard.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 19 V nominal, 18.05–19.95 V range at IZ = 19 mA - defines precise clamping/reference point |
| Power Dissipation (PD) | 500 mW at TA = 25°C - sets maximum continuous DC power handling |
| Dynamic Impedance (ZZ) | 23 Ω at IZ = 19 mA - determines voltage regulation stiffness under load variation |
| Reverse Leakage (IR) | 0.1 μA max at VR = 15.2 V - ensures minimal error current in high-impedance reference nodes |
| Temperature Coefficient | +0.085 %/°C - quantifies voltage drift per degree Celsius rise in junction temperature |
| Package | DO-35 glass, hermetically sealed - provides reliable long-term stability and moisture resistance |
Pinout & Package
DO-35 glass axial package: anode and cathode leads extend from opposite ends of cylindrical glass body; cathode identified by color band near one lead end. Leads are tinned copper-clad steel, 0.46 mm diameter, 25.4 mm minimum length (T50).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward current entry / Reverse breakdown return path | Connected to lower-potential node in Zener configuration; carries full load current during regulation |
| Cathode | Forward current exit / Reverse breakdown voltage reference terminal | Marked with color band; connected to regulated output node; defines reference potential in shunt regulator |
Key Features
| Feature | Design Value |
|---|---|
| ±5% Zener voltage tolerance | Enables predictable clamping within tight margins without post-production trimming |
| Hermetic DO-35 glass construction | Prevents parameter shift due to humidity ingress, supporting >10-year reliability in industrial environments |
| Low reverse leakage (0.1 μA) | Minimizes loading error in high-resistance voltage divider networks used with op-amp references |
| Stable +0.085 %/°C TC | Allows accurate thermal drift compensation when paired with NTC thermistors or complementary devices |
Applications
| Industrial Sensor Signal Conditioning | Low-Power Microcontroller Reset Circuit |
|---|---|
Use Scenario: Stabilizing reference voltage for 12-bit ADC inputs in temperature transmitters operating from 24 V loop supplies. IC Role / Device Role / Timing Role: Shunt voltage reference providing 19 V rail clamp and 5 V LDO input stabilization. Use Value: Maintains ADC full-scale accuracy within ±0.5 LSB over –40°C to +85°C ambient via known TC and low ZZ. | Use Scenario: Generating clean reset threshold for ARM Cortex-M0+ MCU in battery-powered IoT edge node. IC Role / Device Role / Timing Role: Zener-based reset supervisor with RC delay network triggering POR at 19 V drop-out. Use Value: Ensures deterministic reset assertion below 4.5 V VDD while drawing <1 μA quiescent current in sleep mode. |
| Linear Regulator Feedback Divider | ESD Protection Clamp in Analog Front-End |
Use Scenario: Setting output voltage of adjustable LDO (e.g., LM317) via feedback resistor network. IC Role / Device Role / Timing Role: Precision voltage reference element in resistive divider that programs LDO output. Use Value: Achieves ±1% output regulation accuracy over line/load/temperature with no external trim required. | Use Scenario: Protecting op-amp inputs in medical-grade ECG amplifier against ±8 kV HBM ESD events. IC Role / Device Role / Timing Role: Fast-acting shunt clamp limiting transient voltage to ≤20 V during discharge. Use Value: Limits peak input stress to <1.05× VZ, preserving amplifier CMRR and avoiding latch-up. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4742A | 12 V nominal, 1 W rating, DO-41 package, 22 Ω ZZ at 21 mA | Higher power, lower voltage - unsuitable for 19 V reference but better for 12 V rail clamping | Select only if system requires ≥1 W dissipation and 12 V regulation; not a direct replacement for 1N5249B_T50A |
| BZX55C18 | 18 V nominal, ±5%, DO-35, 500 mW, 25 Ω ZZ at 5 mA | Lower Zener voltage, higher ZZ at lower test current - less stable under variable load | Acceptable where 18 V tolerance is acceptable and load current stays near 5 mA; verify thermal drift match |
Compared with 1N4742A and BZX55C18, the 1N5249B_T50A delivers tighter voltage control at 19 V with superior low-current impedance behavior and DO-35 footprint compatibility for space-constrained designs requiring exact 19 V reference stability.
Availability
1N5249B_T50A is available at Aetrix Electronics and suitable for industrial sensor interfaces, low-power microcontroller reset circuits, linear regulator feedback networks, and analog front-end ESD protection requiring stable component supply and long-lifecycle support.
Supply support for 1N5249B_T50A 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
ON Semiconductor is a global semiconductor manufacturer specializing in energy-efficient power, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and consumer markets.
The 1N52xxB series is part of ON Semiconductor's legacy Zener diode portfolio designed for general-purpose voltage regulation and reference applications in cost-sensitive, high-reliability through-hole assemblies.
FAQ
What is the Zener voltage tolerance for 1N5249B_T50A?
The 1N5249B_T50A has a ±5% Zener voltage tolerance, resulting in a guaranteed range of 18.05 V to 19.95 V at 25°C and IZ = 19 mA. This tolerance is laser-trimmed during manufacturing and applies across the full operating junction temperature range of –65°C to +200°C.
Does 1N5249B_T50A have a specified forward voltage?
Yes, the 1N5249B_T50A specifies a maximum forward voltage (VF) of 1.2 V at IF = 200 mA. This value is relevant when the device is used in forward conduction mode, such as in polarity protection or LED driver bias paths, though its primary function is reverse-biased Zener operation.
What is the thermal derating behavior of 1N5249B_T50A above 50°C?
The 1N5249B_T50A derates linearly at 4.0 mW/°C above 50°C ambient temperature. Starting from its 500 mW rating at 25°C, usable power drops to 400 mW at 75°C and 300 mW at 100°C - critical for thermal design in enclosed industrial enclosures.
Can 1N5249B_T50A be used in surface-mount designs?
No, the 1N5249B_T50A is packaged exclusively in the axial DO-35 glass case and is not compatible with SMT reflow or wave soldering. For surface-mount equivalents, consider ON Semiconductor's NZ9F18V or similar SOD-123 Zener diodes - but note these differ in voltage, package, and thermal performance.
What does the "T50A" suffix indicate in 1N5249B_T50A?
The "T50A" suffix denotes lead length specification: T50 indicates minimum 25.4 mm lead length per JEDEC DO-204AH standard, and "A" identifies a specific lead finish and packaging variant per ON Semiconductor's internal ordering nomenclature - confirmed in official ON Semi documentation for the 1N52xxB family.
1N5249B_T50A Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- DO-204AH, DO-35, Axial
- Packaging:
- Tape & Box (TB)
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 19 V
- Tolerance:
- ±5%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 23 Ohms
- Current - Reverse Leakage @ Vr:
- 100 nA @ 14 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.2 V @ 200 mA
- Operating Temperature:
- -65°C ~ 200°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-35
1N5249B_T50A FAQ
1.How can I place an order for 1N5249B_T50A through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N5249B_T50A 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 1N5249B_T50A reliable?
The price and inventory of 1N5249B_T50A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5249B_T50A is usually 5 days.
3.What payment methods are accepted for 1N5249B_T50A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5249B_T50A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N5249B_T50A?
1N5249B_T50A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N5249B_T50A 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 1N5249B_T50A?
For technical support, including 1N5249B_T50A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5249B_T50A requirements.
6.How does Aetrix verify that 1N5249B_T50A is sourced from the original manufacturer or authorized distributors?
All 1N5249B_T50A 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 1N5249B_T50A meets industry standards.
7.What is the process for return or replacement of 1N5249B_T50A?
All 1N5249B_T50A units undergo pre-shipment inspection (PSI). If there is an issue with 1N5249B_T50A, 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 1N5249B_T50A part is unused and in its original packaging.
Return procedure for 1N5249B_T50A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N5249B_T50A Tags
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MMBZ5240B-7-F
Diodes Incorporated
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BZX84C3V3LT1G
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