1N4744A-T50A - 15V 1W Zener Diode DO-41 | Single Zener
MPN： 1N4744A-T50A ✓ 啟用中1N4744A-T50A 概覽
A Zener diode is a specialized pn-junction diode engineered to operate in the reverse-breakdown (Zener) region, where the voltage across the device remains nearly constant over a wide range of reverse current. This makes Zener diodes the building blocks of shunt voltage regulators, precision references, and overvoltage protection clamps. Within the discrete semiconductor hierarchy, Zener diodes belong to the diodes family, sit alongside TVS diodes, Schottky diodes, and rectifier diodes, and form the simplest, lowest-noise class of reference voltage source used in analog and power-conversion circuits.
Key features include a nominal working voltage of 15 V at a test current of 17 mA, ±5% voltage tolerance for the A-suffix series, 1 W maximum DC power dissipation at TL = 50 °C with 3/8 inch lead length (derated above 50 °C), and a broad -65 °C to +175 °C operating and storage temperature range. The silicon-oxide passivated junction delivers stable long-term voltage characteristics under continuous bias. The -T50A suffix denotes an ammo-pack tape-and-axial reel configuration, optimized for automatic through-hole insertion.
The 1N4744A-T50A utilizes a hermetically sealed glass envelope (DO-41 / SOD66) that protects the silicon die against humidity and mechanical stress, while the axial leads simplify PCB layout and heatsinking through copper trace area on each pad. Compared to surface-mount equivalents, the DO-41 package delivers higher intrinsic power dissipation per unit and easier prototyping on perfboard and breadboards.
Typical applications include 15 V shunt voltage regulators in analog signal-conditioning circuits, overvoltage protection clamps on sensor and signal lines, reference voltage sources for ADCs, bias supplies for transistor and op-amp stages, and DC voltage step-down from higher rails. It is also widely used as a precision clamp for PCBs and as a reference for low-power instrumentation.
When designing with this part, observe the 1 W power derating curve above 50 °C lead temperature, keep lead length short to maximize heat conduction into the PCB, and provide adequate copper pad area on both anode and cathode sides to sustain continuous dissipation. For tighter tolerance or surface-mount requirements, consider 1N4744A in SMA/SMB equivalents.
This page consolidates distributor pricing, drop-in alternative MPNs, and practical design notes that extend beyond the manufacturer datasheet for the 1N4744A-T50A.
直接替換替代品，適用於 1N4744A-T50A — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： 1N4744A-T50A （相同外形與佔位） — 差異在於 Package, Power Dissipation (Pd), RoHS Status.
1N4744A
✅ 直接替換聯絡詢價
查看資料表 →1N4744A-TAP
✅ 直接替換📋 參考替代品（不在目錄中）
1N4744A-T
✅ 直接替換📋 參考替代品（不在目錄中）
1N4744A
✅ 直接替換聯絡詢價
查看資料表 →BZX85C15
✅ 直接替換📋 參考替代品（不在目錄中）
1N4744A-T50A 最大額定值與電氣特性
| Diode Type | Zener (Voltage Regulator) |
| Nominal Zener Voltage (Vz) | 15 V |
| Voltage Tolerance | ±5% |
| Zener Test Current (Izt) | 17 mA |
| Maximum Zener Impedance (Zzt) at Izt | 14 Ω |
| Maximum Zener Impedance (Zzk) at 0.25 mA | 700 Ω |
| Maximum Forward Voltage (Vf) at 200 mA | 1.2 V |
| Power Dissipation (Pd) | 1 W (at TL = 50 °C, lead length 3/8") |
| Operating and Storage Temperature Range | -65 °C to +175 °C |
| 封裝 | DO-41 (SOD66), Axial-Lead Glass |
| 安裝類型 | Through Hole |
| Packaging | Ammo Pack (Tape & Axial Reel, -T50A suffix) |
| Junction Passivation | Silicon-Oxide Passivated |
| Configuration | Single, Axial-Leaded Hermetic Glass |
| RoHS 狀態 | Compliant |
1N4744A-T50A 腳位配置
| 腳位 1 | Cathode — Banded end; cathode of the Zener diode |
| 腳位 2 | Anode — Unbanded end; anode of the Zener diode |
典型應用
1N4744A-T50A 適用於 6 應用s: 15 V Shunt Voltage Regulator, Overvoltage Clamp for Sensor and Signal Lines, Precision Voltage Reference Bias, Transistor and Op-Amp Stage Bias Supply, Industrial 24 V Bus Voltage Reference, Hobby and Prototyping Reference.
15 V Shunt Voltage Regulator
The 1N4744A-T50A's 15 V nominal Zener voltage at 17 mA test current and ±5% tolerance make it ideal as a low-noise shunt regulator in analog front-end and instrumentation power trees. Placed between the supply rail and ground with a series resistor (typically 470 Ω–1 kΩ at 15 V supply), it clamps the load to ~15 V with sub-millivripple output, far cleaner than any switching preregulator. Unlike op-amp references, the Zener needs no quiescent current compensation, and the 1 W dissipation budget allows sustained loads of 10–20 mA.
推薦
Overvoltage Clamp for Sensor and Signal Lines
With 1.2 V maximum forward voltage at 200 mA and 14 Ω Zener impedance, the 1N4744A-T50A provides effective low-energy clamping on ADC inputs, op-amp rails, and sensor signal lines that may see transients above the 15 V rail. The hermetic DO-41 glass package resists humidity-induced drift, making it suitable for industrial and outdoor sensor interfaces. Designers pair it with a series PTC or ferrite for high-energy transient robustness, leveraging the Zener for fast sub-microsecond response.
推薦
Precision Voltage Reference Bias
The 1N4744A-T50A delivers a stable 15 V reference when biased at 5–20 mA, suitable for op-amp supply rails, instrumentation-amp reference nodes, and ADC reference ladders. Its ±5% tolerance can be trimmed to ±1% with a series resistor pair, and the 14 Ω Zener impedance gives a temperature coefficient of typically <0.05%/°C at the 17 mA test point. Compared to bandgap IC references, this Zener offers no minimum load requirement and tolerates capacitor-fed dynamic loads.
推薦
Transistor and Op-Amp Stage Bias Supply
In discrete transistor amplifier designs, the 1N4744A-T50A serves as a 15 V bias rail for Class-A amplifier collector loads, JFET drain bias, and op-amp dual-rail midpoint generation. Its 1 W dissipation budget at 50 °C lead temperature is sufficient for powering single-stage preamps and small-signal buffers. The DO-41 axial leads accept standard through-hole PCB pads, simplifying repair and rework in vintage and DIY audio designs.
推薦
Industrial 24 V Bus Voltage Reference
Industrial 24 V PLC and sensor-bus systems often require a 15 V reference derived via series resistor and Zener clamp. The 1N4744A-T50A at 1 W handles continuous 17 mA loads with margin for transient absorption. Its -65 °C to +175 °C operating range covers outdoor and cabinet-mounted equipment. Compared to active 15 V regulator ICs, the Zener requires only two components and provides inherent short-circuit tolerance when properly resistor-limited.
推薦
Hobby and Prototyping Reference
The 1N4744A-T50A is a staple part on breadboards, perfboards, and educational electronics kits because of its through-hole DO-41 form factor, easy hand-soldering, and forgiving 1 W power budget. The -T50A ammo packaging supports volume production but the same electrical die ships in bulk (1N4744A) and tape-and-ammo (1N4744A-TAP) variants. Hobbyists and repair technicians value the DO-41 axial package as a universal Zener footprint compatible with hundreds of legacy designs.
推薦
推薦產品摘要
工程參考資料，適用於 1N4744A-T50A — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | 1N4744A | 1N4744A-TAP | 1N4744A-T | 1N4744A (NXP) | BZX85C15 |
|---|---|---|---|---|---|---|
| Package | DO-41 (SOD66) | DO-41 (SOD66) - same | DO-41 (SOD66) - same | DO-41 (SOD66) - same | DO-41 (SOD66) - same | DO-41 (SOD66) - same |
| Brand | onsemi | onsemi | onsemi | onsemi | NXP Semiconductors | Vishay Intertechnology |
| Nominal Zener Voltage | 15 V | 15 V | 15 V | 15 V | 15 V | 15 V |
| Power Dissipation | 1 W | 1 W | 1 W | 1 W | 1 W | 1.3 W |
| Voltage Tolerance | ±5% | ±5% | ±5% | ±5% | ±5% | ±5% |
| Shipping Form | Ammo Pack (-T50A) | Bulk | Tape & Ammo (-TAP) | Tape & Reel (-T) | Bulk / Ammo | Bulk / Ammo |
主要差異化特點
- Industry-standard JEDEC 1N4744A registration with broad cross-brand second-sourcing (對比BZX85C15)
- Ammo-pack -T50A shipping form for high-volume assembly (對比1N4744A (bulk))
- Wide -65 °C to +175 °C operating range (對比BZX85C15)
設計說明
Estimated: at Vz = 15 V and Izt = 17 mA, the 1N4744A-T50A dissipates approximately 255 mW (Vz × Iz) under typical bias, well within the 1 W rating at TL = 50 °C. To sustain continuous operation, keep lead length to 3/8 inch or less and provide at least 100 mm² of copper pad area on each lead for heat conduction. Derate linearly to zero at TL = 175 °C.
For through-hole Zener diodes in DO-41 packages, use a 1.6 mm or larger pad PCB and metal standoff to maximize thermal conduction into the copper pour. Bend leads minimally to avoid stress on the glass seal. Maintain at least 2 mm spacing between the body and adjacent components for airflow and rework clearance.
Avoid operating the 1N4744A-T50A below its Zener knee current (~1 mA for 15 V), as regulation becomes soft and impedance rises sharply. Always place a series current-limiting resistor to set Iz between 5–25 mA for stable regulation. Do not exceed the 1 W power rating at elevated ambient temperatures without derating.
合規資訊
RoHS and lead-free per onsemi product page; REACH compliant. AEC-Q100 not applicable for through-hole discrete Zener diodes. Halogen-free status not explicitly stated in the verified data.
