1N4744A - 15V 1W Zener Diode DO-41 ±5% | onsemi
部品番号: 1N4744A ✓ 生産中| 数量 | 単価 | 小計 |
|---|---|---|
| 1 | $0.36 | $0.36 |
| 10 | $0.3 | $3.00 |
| 100 | $0.18 | $18.00 |
| 500 | $0.14 | $70.00 |
| 1,000 | $0.11 | $110.00 |
| 5,000 | $0.09 | $450.00 |
1N4744A 概要
A Zener diode is a specialized pn-junction silicon device engineered to operate in the reverse-breakdown region, where the voltage across the diode remains essentially constant over a wide range of reverse currents. In the broader component taxonomy, the 1N4744A belongs to voltage regulator diodes (also called Zener diodes or voltage-reference diodes), which are a subset of discrete semiconductors used for voltage clamping, reference generation, and shunt regulation. Compared to shunt regulator ICs or series linear regulators, Zener diodes offer a simpler, lower-cost solution for low-current, moderate-precision applications.
Key features of the 1N4744A include very sharp reverse breakdown characteristics, low reverse leakage current, a maximum power dissipation of 1 W at 25 °C ambient (derated linearly to 0 W at 175 °C), and an operating and storage temperature range of −65 °C to +175 °C. The hermetically sealed glass DO-41 package provides excellent long-term stability and is suitable for harsh-environment and through-hole industrial designs where SMT components are not appropriate.
Typical applications include low-voltage shunt regulators, voltage references for analog circuits, overvoltage protection clamps, meter protection in analog instruments, and bias supplies for transistor and op-amp circuits. The 15 V nominal voltage makes it especially useful for generating stable references in 12 V nominal systems where some headroom above the rail is required.
When designing with the 1N4744A, ensure the Zener test-current bias (17 mA nominal) is supplied and that the series resistor limits total power dissipation to within the 1 W rating. Thermal management is critical because power dissipation rises quickly when the diode clamps transients. Mounting orientation and lead length both affect thermal resistance to ambient; keep lead lengths short and consider clip-on heatsinks for continuous high-power operation.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, giving engineers a single reference for selecting the 1N4744A across industrial, automotive, and instrumentation applications.
ドロップイン代替品: 1N4744A — 同一パッケージでピン互換。PCBの作り直しが必要な異なるパッケージの部品は除外されています。
このシリーズのバリエーション
同一シリーズでドロップイン互換のモデル: 1N4744A （同一形状・フットプリント） — 相違点: Package, Power Dissipation (Pd), RoHS Status.
クイック比較ツール — 並列比較する代替部品を選択:
1N4744A
✅ ドロップイン✓ 在庫あり
$0.09 / 個
データシートを見る →1N4744A
✅ ドロップイン✓ 在庫あり
$0.09 / 個
データシートを見る →1N4744A-A
✅ ドロップイン📋 参考代替品（カタログ未掲載）
1N4744A TR PBFREE
✅ ドロップイン📋 参考代替品（カタログ未掲載）
BZX85C15
✅ ドロップイン📋 参考代替品（カタログ未掲載）
NTE145A
✅ ドロップイン📋 参考代替品（カタログ未掲載）
1N4744A 最大定格＆電気的特性
| Nominal Zener Voltage (Vz) | 15 V |
| Zener Voltage Tolerance | ±5% |
| Test Current (Izt) | 17 mA |
| Maximum Zener Impedance (Zzt) | 14 Ω at 17 mA |
| Maximum Reverse Leakage (Ir) | 5 µA at 11.4 V |
| Maximum Forward Voltage (Vf) | 1.2 V at 200 mA |
| Power Dissipation (Pd) | 1 W |
| 動作温度範囲 | -65 °C to +175 °C |
| Storage Temperature Range | -65 °C to +175 °C |
| パッケージ | DO-41 (SOD66) axial through-hole |
| Case Material | Hermetically sealed glass |
| 実装タイプ | Through Hole |
| ピン数 | 2 |
| Polarity | Cathode band marked |
| RoHS ステータス | Compliant (TR suffix variants Pb-free) |
| Weight | 0.35 g |
1N4744A ピン構成
| ピン 1 | Anode — Positive terminal; unmarked end of the axial glass body |
| ピン 2 | Cathode — Negative terminal; identified by black polarity band on the glass body |
主な用途
1N4744A の用途: 6 件s: 12V Rail Shunt Regulator, Voltage Reference for Op-Amp Circuits, Overvoltage Protection Clamp, Analog Meter Movement Protection, Bias Supply for Transistor and Op-Amp Stages, Waveform Clipper and Signal Limiter.
12V Rail Shunt Regulator
The 1N4744A's 15 V nominal Zener voltage and 1 W power rating suit 12 V nominal bus clamping where engineers need a stable reference above the rail. With 14 Ω maximum Zener impedance at 17 mA test current and ±5% tolerance per the onsemi datasheet, the diode delivers reliable clamping across −65 °C to +175 °C. Place the 1N4744A between a bias resistor and ground; the series resistor drops (VIN − 15 V) and limits current. Unlike a series regulator, the Zener shunt topology requires no feedback loop and tolerates input transients, making it ideal for automotive 12 V subsystems, battery-backed instrumentation, and analog front ends where simplicity outweighs the need for tight regulation.
おすすめ
Voltage Reference for Op-Amp Circuits
The 1N4744A provides a low-cost 15 V reference for op-amp and ADC front-end circuits where ±2.5% accuracy is acceptable. With 1.2 V max forward drop and 5 µA max reverse leakage at 11.4 V per the onsemi datasheet, the diode biases cleanly from a single supply. Connect the anode to ground and the cathode to a pull-up resistor from the positive rail; the op-amp non-inverting input then sees a stable 15 V reference. Compared with bandgap reference ICs, the 1N4744A trades accuracy for cost and simplicity, so it is best suited to industrial control loops, comparator thresholds, and transducer excitation rather than precision measurement chains requiring sub-1% references.
おすすめ
Overvoltage Protection Clamp
The 1N4744A functions as a robust overvoltage clamp for analog input pins, relay coils, and small signal transformers exposed to inductive transients. Its 1 W power rating absorbs surge energy during fault events while the sharp reverse breakdown characteristic of the onsemi 1N474x series limits peak voltage to 15 V ±5%. Place the diode in reverse parallel with the protected load: during normal operation the 1N4744A remains non-conducting; on overvoltage it clamps the rail to within its Zener voltage, protecting downstream semiconductors. Engineers commonly pair this part with TVS diodes for layered protection in industrial PLCs, automotive ECUs, and instrumentation front-ends where the DO-41 through-hole package simplifies manual rework and field replacement.
おすすめ
Analog Meter Movement Protection
The 1N4744A serves as a classic movement-protection clamp in analog panel meters, D'Arsonval movements, and legacy test equipment where accidental overcurrent can destroy the coil. Connected in reverse parallel across the meter terminals, the Zener conducts only when terminal voltage exceeds 15 V, shunting excess current away from the delicate coil winding. The 1 W dissipation handles transient energy, and the ±5% tolerance ensures protection activates at a predictable threshold. This application leverages the DO-41 axial package, which fits neatly inside instrument enclosures and is easily replaced in the field. Per the onsemi datasheet, the device operates across −65 °C to +175 °C, ensuring reliability in outdoor and industrial metering applications.
おすすめ
Bias Supply for Transistor and Op-Amp Stages
The 1N4744A generates a stable 15 V bias rail for transistor and op-amp stages in discrete analog designs where a separate regulator IC would be overkill. Per the onsemi datasheet, the Zener maintains 15 V ±5% across 5–20 mA bias current with 14 Ω impedance, providing a clean reference for emitter-bias networks, base-bias dividers, and analog multiplier stages. The hermetically sealed DO-41 glass package ensures long-term stability in environments with humidity or vibration, and the axial leads simplify hand-wired and point-to-point construction common in audio preamplifiers, vintage instrument clones, and educational electronics kits. The 1 W dissipation comfortably handles the bias current of typical small-signal amplifier stages.
おすすめ
Waveform Clipper and Signal Limiter
The 1N4744A clips and limits AC signal amplitudes in function generators, audio test sets, and instrumentation where predictable clipping at 15 V is required. With 1.2 V forward drop and sharp 15 V reverse breakdown per the onsemi datasheet, the diode produces asymmetric clipping that can be exploited for overdrive, distortion, or signal squaring applications. Two 1N4744A diodes in opposing parallel create a symmetric ±15 V limiter, while a single device biased through a resistor provides one-sided clipping. The 1 W rating handles continuous signal power in low-frequency circuits, and the DO-41 package supports easy PCB mounting in through-hole audio and instrumentation designs where SMT components are not desired.
おすすめ
おすすめ製品の概要
エンジニアリング参考データ: 1N4744A — 比較、設計ガイダンス、コンプライアンス情報。
選定ガイド
代替品との比較
| パラメータ | この製品 | 1N4744A (NXP) | 1N4744A (Vishay) | 1N4744A-A | BZX85C15 | NTE145A |
|---|---|---|---|---|---|---|
| Brand | onsemi | NXP Semiconductors | Vishay Intertechnology | Diodes Incorporated | Vishay Intertechnology | NTE Electronics |
| Package | DO-41 (SOD66) | DO-41 (SOD66) - same | DO-41 (SOD66) - same | DO-41 (SOD66) - same | DO-41 (SOD66) - same | DO-41 (SOD66) - same |
| Nominal Zener Voltage | 15 V | 15 V | 15 V | 15 V | 15 V | 15 V |
| Zener Voltage Tolerance | ±5% | ±5% | ±5% | ±5% | ±5% | ±5% |
| Power Dissipation | 1 W | 1 W | 1 W | 1 W | 1.3 W (slightly higher rating) | 1 W |
| Operating Temperature Range | -65 °C to +175 °C | -65 °C to +175 °C | -65 °C to +175 °C | -65 °C to +175 °C | -55 °C to +175 °C (typical) | -65 °C to +175 °C |
主な差別化要因
- Original JEDEC-registered 1N4744A part number from onsemi （vs 1N4744A-A (Diodes Incorporated))
- Lower power dissipation rating (1 W vs 1.3 W) （vs BZX85C15 (Vishay))
- Wider operating temperature range (-65 °C to +175 °C) （vs BZX85C15 (Vishay))
設計ノート
Estimated: at 1 W continuous dissipation with standard 25 mm lead length, junction-to-ambient thermal resistance is approximately 110 °C/W per the onsemi datasheet. Junction temperature rise above ambient = 1 W × 110 °C/W = 110 °C. Keep lead lengths under 5 mm or add a clip-on heatsink to drop θJA to 50–60 °C/W and ensure the junction stays below the 175 °C limit. For pulsed loads, peak power can exceed 1 W briefly because the thermal mass of the DO-41 glass body absorbs transient energy.
For through-hole designs, drill 0.9 mm–1.0 mm lead holes and leave 1.5 mm pad annular ring around each hole for hand-soldering reliability. Bend leads at least 2 mm from the glass body to avoid mechanical stress cracking the hermetic seal. Maintain 5 mm clearance between the diode body and adjacent tall components to allow clip-on heatsink installation. For vibration environments, secure the body with a dab of RTV silicone or a cable tie to the chassis.
Do not exceed 1 W continuous dissipation or the junction will overheat and the Zener voltage will drift outside the ±5% spec. The reverse leakage of 5 µA at 11.4 V is specified at 25 °C; leakage rises sharply above 100 °C, so high-temperature designs must budget for additional bias current. When using as a shunt regulator, the series resistor must drop (VIN − VZ) at the maximum load current while limiting total current to within the 1 W rating. A common error is forgetting that Zener impedance (14 Ω) modulates dynamic impedance — for low-noise references add a 1–10 µF capacitor across the diode to bypass noise above 1 kHz.
コンプライアンス情報
RoHS compliance per onsemi product page. Standard 1N4744A is not AEC-Q100 qualified; for automotive applications requiring AEC-Q100, source the automotive-screened variant from onsemi or use the Vishay or NXP equivalent through automotive distribution channels.
