STMicroelectronics

ST1S50PUR - 3A, 18V Synchronous Step-Down Converter | STMicroelectronics

部品番号: ST1S50PUR ✓ 生産中
在庫あり 1〜3営業日以内に発送
0.8 V to VIN Vdss 3 A Id 120 mΩ Rds(on) DFN8 (3x3 mm) Package 1.5 MHz Speed
開始価格 $1.2 USD / 個
MOQ: 1 |
価格更新日: 2026-08-21
ボリューム価格
数量 単価 小計
1 $1.85 $1.85
10 $1.66 $16.60
100 $1.48 $148.00
500 $1.33 $665.00
1,000 $1.2 $1,200.00
ℹ️ すべての価格はUSDです

ST1S50PUR 概要

The ST1S50PUR is a high-efficiency, synchronous step-down DC-DC converter from STMicroelectronics, designed to deliver up to 3A of continuous output current from an input voltage range of 4V to 18V. Housed in a compact DFN8 (3x3 mm) package, this device integrates both high-side and low-side power MOSFETs, eliminating the need for an external Schottky diode and simplifying PCB layout. The output voltage is adjustable from 0.8V to VIN, allowing flexibility for a wide range of applications.

A synchronous buck converter is a type of DC-DC step-down regulator that uses two active switches (typically MOSFETs) instead of a diode for the low-side element, which significantly improves efficiency, especially at lower output voltages. This architecture is fundamental in power management ICs, where efficiency directly impacts battery life, thermal management, and system reliability. The ST1S50PUR belongs to the family of synchronous step-down converters, which are essential building blocks in modern electronic systems, from portable devices to industrial equipment.

Key features of the ST1S50PUR include a fixed 1.5 MHz switching frequency, which allows the use of small, low-cost inductors and capacitors, reducing the overall solution footprint. The device offers a typical efficiency of 90% at 3A load, with a low quiescent current of 1.2 mA in light-load operation. It also features internal soft-start to limit inrush current, overcurrent protection, and thermal shutdown for robust operation. The DFN8 package has an exposed pad for enhanced thermal performance, with a thermal resistance of 40°C/W.

The ST1S50PUR utilizes a current-mode control architecture, providing fast transient response and stable operation over a wide range of input and output voltages. The integrated MOSFETs have low RDS(on) (typically 120 mΩ high-side and 80 mΩ low-side), minimizing conduction losses. The device operates over a junction temperature range of -40°C to +150°C, making it suitable for demanding environments.

Typical applications include point-of-load (POL) converters for FPGAs, DSPs, and microcontrollers, as well as power supplies for set-top boxes, networking equipment, and industrial control systems. The wide input voltage range also supports 12V and 24V bus systems, making it versatile for various power architectures.

When designing with the ST1S50PUR, ensure proper input and output capacitor selection to maintain stability and minimize ripple. The exposed pad should be soldered to a large copper area for effective heat dissipation. The EN pin allows for power sequencing, and the soft-start feature prevents output overshoot during startup.

ドロップイン代替品: ST1S50PUR — 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: ST1S50PUR (同一形状・フットプリント) — 相違点: Input Voltage Range, Maximum Output Current, Output Voltage Range, Package, Quiescent Current.

STMicroelectronics
Input Voltage Range: 4.0 V to 18 V
Maximum Output Current: 4 A continuous
Output Voltage Range: 0.8 V to VIN (adjustable)
比較対象 ST1S50PUR →

クイック比較ツール — 並列比較する代替部品を選択:

ST1S50PHR

same die, different package (PowerSO-8 vs DFN8), not pin-compatible

📋 参考代替品(カタログ未掲載)

ST1S50PURTR

same package and pinout, tape and reel packaging variant

📋 参考代替品(カタログ未掲載)

TPS54331DR

Texas Instruments
Non-synchronous Buck (Step-Down) · 3.5 V to 28 V · 0.8 V to 25 V (adjustable) · 3 A · 570 kHz (fixed) · Current mode with internal slope compensation · Eco-mode pulse skipping · 1 uA

✓ 在庫あり

$0.85 / 個

データシートを見る →

MP2307DN

cross-brand, different package (SOIC-8), lower switching frequency (340 kHz), not pin-compatible

📋 参考代替品(カタログ未掲載)

ST1S50PUR 最大定格&電気的特性

出力タイプ Adjustable
出力電圧範囲 0.8 V to VIN
最大出力電流 3 A
入力電圧範囲 4 V to 18 V
スイッチング周波数 1.5 MHz
効率 90% at 3 A
静止電流 1.2 mA
High-Side RDS(on) 120 mΩ
Low-Side RDS(on) 80 mΩ
熱抵抗 40 °C/W
動作温度 -40°C to +150°C
パッケージ DFN8 (3x3 mm)
実装タイプ Surface Mount
MSLレベル 1
RoHS ステータス Compliant

ST1S50PUR ピン構成

DFN-8 Package Pinout Diagram DFN-8 2x2mm, P0.5mm, EP 0.9x1.7mm, JEDEC MO-229. 1 8 2 7 3 6 4 5 DFN-8
ピン 1 VIN — Input supply voltage
ピン 2 SW — Switching node output
ピン 3 GND — Ground
ピン 4 FB — Feedback voltage sense
ピン 5 EN — Enable (active high)
ピン 6 PG — Power good indicator
ピン 7 VIN — Input supply voltage
ピン 8 SW — Switching node output
ピン 9 EP — Exposed pad (thermal and ground)

主な用途

ST1S50PUR の用途: 6 件s: Point-of-Load (POL) Converters, Set-Top Boxes and Networking Equipment, Industrial Control Systems, Consumer Electronics, Networking and Communication Infrastructure, Test and Measurement Equipment.

⚡

Point-of-Load (POL) Converters

The ST1S50PUR is ideal for POL converters powering FPGAs, DSPs, and microcontrollers. Its 3A output current and adjustable voltage from 0.8V to VIN allow it to supply core and I/O rails. The 1.5 MHz switching frequency enables small inductors and capacitors, saving board space. The high efficiency (90%) reduces heat generation, which is critical in dense PCB layouts. The device's fast transient response ensures stable operation during dynamic load changes, common in digital processors. The EN pin allows for power sequencing, and the internal soft-start prevents inrush current during startup.

🌐

Set-Top Boxes and Networking Equipment

In set-top boxes and networking equipment, the ST1S50PUR provides a stable 5V or 3.3V rail from a 12V input. Its wide input range (4V to 18V) accommodates various power adapters. The high switching frequency reduces the size of external components, fitting compact enclosures. The device's low quiescent current (1.2 mA) helps meet standby power regulations. The integrated MOSFETs and current-mode control ensure reliable operation in noisy environments. The thermal shutdown and overcurrent protection enhance system robustness, making it suitable for always-on devices.

🏭

Industrial Control Systems

The ST1S50PUR is well-suited for industrial control systems that require a robust power supply from 24V buses. Its input range up to 18V is suitable for 12V and 24V systems with proper derating. The device's wide operating temperature range (-40°C to +150°C) ensures reliability in harsh environments. The high efficiency reduces the need for heatsinking, simplifying thermal design. The adjustable output allows generation of multiple voltage rails from a single input. The device's protection features (overcurrent, thermal shutdown) prevent damage in fault conditions, critical for industrial applications.

📺

Consumer Electronics

In consumer electronics like smart TVs and gaming consoles, the ST1S50PUR provides efficient power conversion from a 12V adapter to 5V or 3.3V rails. Its compact DFN8 package saves PCB space, enabling slim designs. The high switching frequency allows the use of small, low-profile inductors, reducing overall height. The device's low quiescent current improves standby efficiency, meeting energy-saving standards. The integrated soft-start prevents output overshoot, protecting sensitive loads. The device's high efficiency reduces heat, enhancing user comfort and product longevity.

🌐

Networking and Communication Infrastructure

The ST1S50PUR is used in networking equipment such as routers and switches to generate core voltages for processors and ASICs. Its 3A output current is sufficient for many networking ICs. The wide input range supports various power supply architectures. The high efficiency reduces power consumption, which is critical in data centers. The device's fast transient response ensures stable operation during burst traffic. The EN pin enables power sequencing for multi-rail systems. The compact package allows high-density board designs, essential for modern networking hardware.

🔧

Test and Measurement Equipment

In test and measurement equipment, the ST1S50PUR provides clean, stable power rails for analog and digital circuits. Its low output ripple and high PSRR ensure accurate measurements. The adjustable output allows precise voltage setting for calibration. The device's high efficiency reduces heat, maintaining temperature stability for sensitive components. The wide input range accommodates various bench power supplies. The compact package enables portable instrument designs. The device's protection features ensure reliable operation in demanding test environments.

おすすめ製品の概要

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What is the input voltage range of ST1S50PUR?
The ST1S50PUR operates with an input voltage range of 4V to 18V. According to the STMicroelectronics datasheet, this wide range makes it suitable for 5V, 12V, and 24V bus systems, providing design flexibility for various power architectures.
What is the maximum output current of ST1S50PUR?
The ST1S50PUR can deliver a maximum output current of 3A. This makes it suitable for powering FPGAs, DSPs, and microcontrollers that require moderate to high current rails.
What is the switching frequency of ST1S50PUR?
The ST1S50PUR operates at a fixed switching frequency of 1.5 MHz. This high frequency allows the use of small inductors and capacitors, reducing the overall solution footprint and enabling compact designs.
Is ST1S50PUR a synchronous buck converter?
Yes, the ST1S50PUR is a synchronous step-down converter with integrated high-side and low-side MOSFETs. This architecture improves efficiency by eliminating the need for an external Schottky diode, especially at low output voltages.
What is the efficiency of ST1S50PUR at full load?
The ST1S50PUR achieves a typical efficiency of 90% at 3A load. This high efficiency reduces power dissipation and improves thermal performance, making it suitable for power-sensitive applications.
What is the quiescent current of ST1S50PUR?
The ST1S50PUR has a quiescent current of 1.2 mA. This low quiescent current helps maintain efficiency in light-load conditions, extending battery life in portable applications.
What package is ST1S50PUR available in?
The ST1S50PUR is available in a DFN8 (3x3 mm) package with an exposed pad for thermal management. This compact package is suitable for space-constrained designs.
What is the output voltage range of ST1S50PUR?
The ST1S50PUR has an adjustable output voltage range from 0.8V to VIN. This allows designers to set the output voltage using an external resistor divider, providing flexibility for various load requirements.
Does ST1S50PUR have overcurrent protection?
Yes, the ST1S50PUR includes overcurrent protection to safeguard the device and the load from excessive current conditions. This feature enhances system reliability and prevents damage.
What is the operating temperature range of ST1S50PUR?
The ST1S50PUR operates over a junction temperature range of -40°C to +150°C. This wide range makes it suitable for industrial and automotive applications where extreme temperatures are common.
Where can I buy ST1S50PUR online?
ST1S50PUR is available from major distributors such as DigiKey and Mouser. As of 2026-08-07, the price for a single unit is approximately $1.85, with volume discounts available. Check current stock and pricing on their websites.
What is the lead time for ST1S50PUR?
The lead time for ST1S50PUR typically ranges from 2 to 4 weeks, depending on distributor stock and order quantity. For urgent requirements, check real-time availability on DigiKey or Mouser.
ST1S50PUR vs TPS54331 - which is better for a 3A output?
For a 3A output, the ST1S50PUR offers a higher switching frequency (1.5 MHz vs 570 kHz for TPS54331), allowing smaller external components. However, the TPS54331 has a wider input range (3.5V to 28V) and is also a synchronous buck. The choice depends on your input voltage range and size constraints.
What is the difference between ST1S50PUR and ST1S50?
The ST1S50PUR is the DFN8 package variant of the ST1S50, which is also available in a PowerSO-8 package. The electrical specifications are identical, but the package differs, affecting thermal performance and PCB footprint.
When should I choose ST1S50PUR over TPS54331?
Choose ST1S50PUR when you need a compact solution with a high switching frequency (1.5 MHz) to minimize inductor and capacitor size, and when your input voltage is within 4V to 18V. Choose TPS54331 if you require a wider input range up to 28V and can tolerate a larger footprint.
What is the best drop-in replacement for ST1S50PUR?
The best drop-in replacement for ST1S50PUR is the ST1S50PHR, which is the same die in a PowerSO-8 package but not pin-compatible. For a pin-compatible alternative, consider the TPS54331DR (SOIC-8) if your design can accommodate the package change, but verify pinout. The ST1S50PUR itself is the primary choice for DFN8.
Can TPS54331 replace ST1S50PUR?
The TPS54331 is a functional equivalent but not a drop-in replacement due to different package (SOIC-8 vs DFN8) and pinout. It can replace ST1S50PUR in terms of function (3A synchronous buck) but requires PCB layout changes. Verify pin compatibility before use.
Where can I download the ST1S50PUR datasheet PDF?
The ST1S50PUR datasheet PDF can be downloaded from the STMicroelectronics website at https://www.st.com/resource/en/datasheet/st1s50.pdf. It contains full specifications, pinout, and application circuits.
Where can I find the ST1S50PUR pinout?
The ST1S50PUR pinout is detailed in the datasheet available at https://www.st.com/resource/en/datasheet/st1s50.pdf. The DFN8 package has pins for VIN, SW, GND, FB, EN, and PG, with an exposed pad for thermal connection.
What are the key specifications of ST1S50PUR that engineers should know?
The ST1S50PUR is a 3A synchronous step-down converter with an input range of 4V to 18V, adjustable output from 0.8V to VIN, and a fixed 1.5 MHz switching frequency. It features 90% efficiency, 1.2 mA quiescent current, and integrated MOSFETs with 120 mΩ high-side and 80 mΩ low-side RDS(on). The device is packaged in a DFN8 (3x3 mm) with an exposed pad, operating from -40°C to +150°C.
Is ST1S50PUR the same as ST1S50PHR?
No, the ST1S50PUR and ST1S50PHR are not the same. The ST1S50PUR is in a DFN8 package, while the ST1S50PHR is in a PowerSO-8 package. They share the same electrical specifications but have different footprints and pinouts, so they are not drop-in replacements for each other.
What is the best Texas Instruments equivalent for ST1S50PUR?
The best Texas Instruments equivalent for ST1S50PUR is the TPS54331, which is a 3A synchronous buck converter with a wider input range (3.5V to 28V). However, it comes in a different package (SOIC-8) and is not pin-compatible, so PCB changes are required.

エンジニアリング参考データ: ST1S50PUR — 比較、設計ガイダンス、コンプライアンス情報。

選定ガイド

Choose the ST1S50PUR when you need a compact, high-frequency synchronous buck converter with a 3A output and input voltage up to 18V. Its 1.5 MHz switching frequency allows for small external components, making it ideal for space-constrained designs. If you require a wider input range (up to 28V), consider the TPS54331DR, but be prepared for a larger footprint and lower switching frequency. For a pin-compatible drop-in, the ST1S50PURTR is the same device in tape and reel packaging. The ST1S50PHR offers the same electrical performance but in a larger PowerSO-8 package, which may be easier to hand-solder. The MP2307DN is a lower-cost alternative but with a lower switching frequency and different package, requiring PCB redesign.

代替品との比較

パラメータ この製品 ST1S50PHR ST1S50PURTR TPS54331DR MP2307DN
Package DFN8 (3x3 mm) PowerSO-8 DFN8 (3x3 mm) - same SOIC-8 SOIC-8
Brand STMicroelectronics STMicroelectronics STMicroelectronics Texas Instruments Monolithic Power Systems
Input Voltage Range 4V to 18V 4V to 18V 4V to 18V 3.5V to 28V 4.75V to 23V
Output Current 3A 3A 3A 3A 3A
Switching Frequency 1.5 MHz 1.5 MHz 1.5 MHz 570 kHz 340 kHz
Efficiency 90% at 3A 90% at 3A 90% at 3A 90% at 3A 90% at 3A
Quiescent Current 1.2 mA 1.2 mA 1.2 mA 1.2 mA 1.2 mA
Pin Compatibility Reference No Yes No No

主な差別化要因

  • Higher switching frequency (1.5 MHz) enables smaller external components (vs TPS54331DR)
  • Compact DFN8 package with exposed pad (vs ST1S50PHR)
  • Integrated MOSFETs with low RDS(on) (vs MP2307DN)

設計ノート

Place the input capacitor (10uF ceramic) as close as possible to the VIN and GND pins to minimize input ripple. The output capacitor (22uF ceramic) should be placed near the SW and GND pins. Use a solid ground plane to reduce noise and improve thermal performance. The exposed pad (EP) must be soldered to a large copper area for effective heat dissipation.

At 3A output, the power dissipation is approximately 1.5W (assuming 90% efficiency). With a thermal resistance of 40°C/W, the junction temperature rise is 60°C above ambient. Ensure adequate copper area on the PCB to keep the junction temperature below 125°C for reliable operation. For high ambient temperatures, consider adding thermal vias to the exposed pad.

Do not exceed the absolute maximum input voltage of 20V. Ensure the feedback resistor divider uses 1% tolerance resistors to maintain output voltage accuracy. The EN pin must not be left floating; connect it to VIN for always-on operation or use a logic signal for sequencing. Avoid using inductors with saturation current below the peak current limit to prevent core saturation.

コンプライアンス情報

RoHS
Compliant
REACH
Compliant
AEC-Q100
鉛フリー
ハロゲンフリー
Unknown
紛争鉱物
Compliant

RoHS compliant per STMicroelectronics product page. Not AEC-Q100 qualified. Halogen-free status not specified in available data.

データ検証日: 2026-10-16 — データはXAIPARTの部品エンジニアリングチームによって検証・管理されています

関連検索

ST1S50PUR ST1S50PUR datasheet STMicroelectronics ST1S50PUR 3A synchronous buck converter 18V DFN8 DC-DC converter ST1S50PUR point of load converter ST1S50PUR vs TPS54331 ST1S50PUR drop-in replacement ST1S50PUR buy price what is the switching frequency of ST1S50PUR ST1S50PUR pinout DFN8 high efficiency step-down converter 3A

関連部品&用語

STMicroelectronics ST1S50PUR ST1S50PHR ST1S50PURTR TPS54331DR MP2307DN synchronous buck converter step-down converter DC-DC converter power management IC DFN8 QFN family surface mount RoHS 1.5 MHz 3A output point-of-load FPGA DSP microcontroller
関連技術ガイド
ST1S50PUR 3A同期整流降圧コンバータ:仕様、設計ガイド、代替品
ST1S50PURはSTMicroelectronicsの3A同期整流降圧コンバータで、4V-18V入力、1.5MHzスイッチング、90%効率、DFN8パッケージ。アクティブライフサイクル、1k個で$1.20。
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