ST1S10PHR - 3A, 18V Synchronous Step-Down Converter | STMicroelectronics
部品番号: ST1S10PHR ✓ 生産中| 数量 | 単価 | 小計 |
|---|---|---|
| 1 | $1.62 | $1.62 |
| 10 | $1.45 | $14.50 |
| 100 | $1.21 | $121.00 |
| 500 | $0.98 | $490.00 |
| 1,000 | $0.78 | $780.00 |
ST1S10PHR 概要
What is a synchronous step-down (buck) DC-DC converter? A buck converter is a switched-mode power supply topology that converts a higher DC input voltage to a lower DC output voltage by periodically storing energy in an inductor and releasing it to the load through a smoothing capacitor. The 'synchronous' qualifier means the free-wheeling diode is replaced by a second MOSFET, which dramatically reduces conduction losses at high current. Buck converters belong to the broader power management IC hierarchy: switching regulator -> DC-DC converter -> PMIC -> semiconductor. They are preferred over linear regulators whenever VIN is more than a few hundred millivolts above VOUT, because efficiency can exceed 90 % versus the VIN/VOUT ratio limit of an LDO.
Key specifications of the ST1S10PHR include 3 A continuous output current, 2.5 V to 18 V input voltage range, 0.8 V minimum feedback voltage, and a typical quiescent current of 1.5 mA. The fixed 900 kHz switching frequency allows the use of a small 4.7 µH to 10 µH inductor and low-ESR ceramic output capacitors, minimizing the total solution footprint to roughly 100 mm². Internal soft-start, cycle-by-cycle current limit, and thermal shutdown protect the device and downstream components during fault and startup events.
Architecturally, the device uses peak current-mode control with an internal compensation network, which simplifies external loop design and provides fast transient response to load steps. The integrated 80 mΩ high-side and 60 mΩ low-side MOSFETs, combined with a thermally efficient exposed-pad PowerSO-8 package, allow sustained 3 A operation without an external heatsink at moderate ambient temperatures. The SYNC/INH pin enables frequency synchronization to an external clock for noise-sensitive multi-rail systems.
Typical applications include point-of-load regulation for FPGAs, DSPs, and microprocessors from a 5 V or 12 V bus, distributed power architectures in networking and telecom equipment, set-top boxes, LCD displays, and industrial control boards. The wide VIN range also makes it suitable for battery-powered portable systems running from 2-cell lithium packs.
When designing with the ST1S10PHR, place input ceramic capacitors as close as possible to the VIN and PGND pins to minimize switching noise, and solder the exposed pad to a copper area of at least 50 mm² for thermal dissipation. Use 1 % tolerance resistors in the feedback divider to maintain output voltage accuracy, and verify inductor saturation current exceeds the peak switch current limit.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, helping engineers select, source, and implement the ST1S10PHR with confidence.
ドロップイン代替品: ST1S10PHR — 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: ST1S10PHR （同一形状・フットプリント） — 相違点: Package, Input Voltage Range, Switching Frequency, Operating Temperature Range, Output Voltage Range.
クイック比較ツール — 並列比較する代替部品を選択:
ST1S14PHR
✅ ドロップイン✓ 在庫あり
$1.6 / 個
データシートを見る →L7987LTR
✅ ドロップイン✓ 在庫あり
$2.7728 / 個
データシートを見る →ST1S41PUR
✅ ドロップイン✓ 在庫あり
$0.92 / 個
データシートを見る →L7986A
✅ ドロップイン✓ 在庫あり
$1.82 / 個
データシートを見る →TPS5430DR
✅ ドロップイン📋 参考代替品（カタログ未掲載）
LM2592HVS-5.0/NOPB
✅ ドロップイン✓ 在庫あり
$2.3 / 個
データシートを見る →ST1S10PHR 最大定格＆電気的特性
| トポロジー | Synchronous Step-Down (Buck) |
| 入力電圧範囲 | 2.5 V to 18 V |
| 出力電圧範囲 | 0.8 V to 0.85 x VIN (adjustable) |
| 最大出力電流 | 3 A |
| スイッチング周波数 | 900 kHz fixed (400 kHz to 1.2 MHz with external sync) |
| Control Mode | Peak Current-Mode PWM |
| Typical Quiescent Current | 1.5 mA |
| 効率 | Up to 90 % at full load |
| 帰還電圧 | 0.8 V (VFB reference) |
| 動作温度範囲 | -40 °C to +125 °C |
| パッケージ | PowerSO-8 (HSOP-8) exposed pad |
| 実装タイプ | Surface Mount |
| MSLレベル | 3 (per JEDEC J-STD-020) |
| Synchronization Input | Yes (SYNC/INH pin, 400 kHz to 1.2 MHz) |
| Protection Features | Cycle-by-cycle current limit, thermal shutdown, internal soft-start |
| RoHS ステータス | Compliant |
ST1S10PHR ピン構成
| ピン 1 | BOOT — Bootstrap capacitor connection for high-side gate driver |
| ピン 2 | IN — Input voltage supply (2.5 V to 18 V) |
| ピン 3 | SW — Switch node - inductor connection point |
| ピン 4 | PGND — Power ground return for low-side MOSFET |
| ピン 5 | FB — Feedback voltage input (0.8 V reference) |
| ピン 6 | COMP — Compensation node for external loop stability components |
| ピン 7 | EN/SYNC — Enable input and external clock synchronization (400 kHz to 1.2 MHz) |
| ピン 8 | SGND — Signal ground reference for FB and COMP |
| ピン 9 | EP — Exposed thermal pad - must be soldered to PCB copper pour for thermal dissipation |
主な用途
ST1S10PHR の用途: 6 件s: FPGA Point-of-Load (POL) Regulation, DSP and Microprocessor Core Rails, Set-Top Box and LCD TV Power, Industrial Control and Distributed Power, Networking and Telecom Equipment, Battery-Powered Portable Systems.
FPGA Point-of-Load (POL) Regulation
The ST1S10PHR's 3 A output and 0.8 V to 3.3 V adjustable range make it a direct fit for powering FPGA core and I/O rails from a 5 V or 12 V bus. The 900 kHz switching frequency keeps the output ripple below 30 mV peak-to-peak when paired with a 22 µF ceramic output capacitor, well within the tolerance of most FPGA power-supply requirements. Compared to a discrete synchronous buck using external MOSFETs and a controller IC, the ST1S10PHR reduces the BOM by 6-8 components and shrinks the solution footprint to roughly 100 mm², which is critical in space-constrained FPGA mezzanine cards. Designers should place the input capacitor within 5 mm of the VIN pin and use a 4.7 µH shielded inductor with saturation current above 4 A.
おすすめ
DSP and Microprocessor Core Rails
Modern DSPs and ARM Cortex microprocessors often require tightly regulated 1.0 V to 1.8 V rails at 2-3 A from a 5 V or 12 V supply. The ST1S10PHR delivers this with internal compensation that simplifies loop design, eliminating the need for external compensation components. Peak current-mode control provides fast transient response, recovering from a 1 A load step in under 50 µs - critical for DSP sleep-to-active transitions. The 1.5 mA quiescent current also makes the part suitable for always-on auxiliary rails that must remain energized even in low-power system states. Use the EN/SYNC pin to sequence the core rail after the I/O rail for proper processor startup.
おすすめ
Set-Top Box and LCD TV Power
Set-top boxes and LCD TVs typically distribute 12 V or 5 V from an internal AC-DC front end and require multiple downstream rails at 3.3 V, 1.8 V, and 1.2 V. The ST1S10PHR's 2.5 V to 18 V input range supports direct conversion from a 12 V bus without an intermediate regulator, while the PowerSO-8 exposed-pad package handles the 1-2 W of dissipation at 3 A output. The fixed 900 kHz frequency avoids interference with common consumer video frequencies (54 MHz to 1.5 GHz), and the internal soft-start prevents the input capacitor inrush that could trip upstream fuse or PFC protection. A typical application delivers 3.3 V at 2.5 A from a 12 V input at 88 % efficiency.
おすすめ
Industrial Control and Distributed Power
Industrial PLCs and distributed I/O modules typically operate from a 24 V nominal bus (with transients up to 36 V), making the ST1S10PHR's 18 V maximum input a tight fit at the upper end. For designs that need 24 V tolerance, the L7987LTR (4.5 V to 28 V) in the same package is a drop-in upgrade. The ST1S10PHR is well suited to 12 V and 5 V intermediate buses in industrial equipment, where its current-mode control rejects input voltage disturbances from relay switching. Cycle-by-cycle current limit and thermal shutdown provide robust fault protection in harsh factory environments, and the -40 °C to +125 °C operating range covers most industrial temperature specifications.
おすすめ
Networking and Telecom Equipment
Networking switches, routers, and telecom line cards commonly use 12 V or 5 V intermediate distribution and require multiple POL converters to power Ethernet PHYs, FPGAs, and switch ASICs. The ST1S10PHR's 900 kHz switching frequency can be synchronized to an external clock via the SYNC pin (400 kHz to 1.2 MHz range), allowing multiple converters in a chassis to switch at the same frequency and avoid beat-frequency EMI. The exposed-pad PowerSO-8 package delivers 3 A continuously in 50 °C ambient airflow without a heatsink, supporting dense multi-rail designs. Designers should synchronize to a frequency offset from system clocks (such as 800 kHz or 1 MHz) to avoid coupling into sensitive analog blocks.
おすすめ
Battery-Powered Portable Systems
Portable devices running from 2-cell lithium battery packs (6 V to 8.4 V) or USB-C 5 V inputs can use the ST1S10PHR to generate 3.3 V or 1.8 V rails for sensors, microcontrollers, and wireless radios. The 1.5 mA quiescent current preserves battery life in standby, and the 90 % peak efficiency at moderate loads (1-2 A) extends runtime. The low minimum VIN of 2.5 V supports single-cell Li-ion designs (with VIN >= 2.5 V at light load, when the cell voltage drops below 3 V). For designs requiring > 3 A peak current (such as cellular RF power amplifiers), the ST1S41PUR (4 A) in the same package provides a higher-current upgrade path.
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: ST1S10PHR — 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 | ST1S14PHR | L7987LTR | ST1S41PUR | TPS5430DR |
|---|---|---|---|---|---|
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics | Texas Instruments |
| Package | PowerSO-8 (HSOP-8) exposed pad | PowerSO-8 (HSOP-8) exposed pad - same | PowerSO-8 (HSOP-8) exposed pad - same | PowerSO-8 (HSOP-8) exposed pad - same | SOIC-8 PowerPAD - same family |
| Input Voltage Range | 2.5 V to 18 V | 2.5 V to 18 V | 4.5 V to 28 V | 2.5 V to 18 V | 5.5 V to 36 V |
| Maximum Output Current | 3 A | 3 A | 3 A | 4 A | 3 A |
| Switching Frequency | 900 kHz fixed | 850 kHz fixed | 250 kHz to 1.5 MHz adjustable | 900 kHz fixed | 500 kHz fixed |
| Synchronization Input | Yes (400 kHz to 1.2 MHz) | Yes | Yes | Yes | No |
| Topology | Synchronous Buck | Synchronous Buck | Synchronous Buck | Synchronous Buck | Non-Synchronous Buck (external diode) |
主な差別化要因
- Synchronous rectification eliminates external Schottky diode （vs LM2592HVS-5.0/NOPB)
- Higher switching frequency enables smaller inductor and capacitors （vs TPS5430DR)
- Wide VIN range covers both 5 V and 12 V bus systems （vs L7986A)
設計ノート
Estimated: at VOUT = 3.3 V, VIN = 12 V, IOUT = 3 A, duty cycle D = 0.275, assuming RDS_on_HS = 0.08 Ω and RDS_on_LS = 0.06 Ω, conduction loss is approximately IOUT² × (D × 0.08 + (1-D) × 0.06) = 1.42 W. Adding switching losses (≈ 0.3 W at 900 kHz), total power dissipation ≈ 1.7 W. The PowerSO-8 package has a junction-to-ambient thermal resistance of approximately 40 °C/W on a 4-layer JEDEC test board, giving a junction temperature rise of 68 °C above ambient. To sustain 3 A at 85 °C ambient, the exposed pad must be soldered to at least 50 mm² of 2 oz copper on top and bottom layers, connected by thermal vias.
Place the input ceramic capacitor (typically 22 µF X7R 25 V) within 5 mm of the VIN pin and PGND pin, with wide traces to minimize switching loop inductance. The BOOT capacitor (typically 100 nF) should be located within 2 mm of the BOOT and SW pins. Keep the feedback (FB) trace short and away from the SW node to avoid noise injection - a 10 mm maximum length with ground shielding is recommended. The exposed pad must be soldered to a continuous copper pour, not a star-ground pattern, for optimal thermal spreading.
Route the SW node on the top layer only and minimize its copper area to reduce radiated EMI. Place the input capacitor, inductor, and output capacitor in a tight loop with the IC - the high di/dt switching current path should enclose the smallest possible area. Use a ground plane on the layer immediately below the power components to provide a low-impedance return path. Avoid routing sensitive analog signals (such as the FB trace) under the inductor or SW node. Source: STMicroelectronics ST1S10 datasheet PCB layout guidelines section.
Do not exceed the absolute maximum VIN of 19 V - voltage transients above this can damage the internal MOSFETs. The feedback divider resistors should use 1 % tolerance to maintain VOUT accuracy better than ±2 %. When using the SYNC function, ensure the external clock amplitude is at least 2 V and the pulse width exceeds 100 ns. Avoid using ceramic output capacitors below 22 µF total, as the ST1S10PHR's internal compensation is optimized for 22 µF to 100 µF of output capacitance. If smaller capacitance is required, add external compensation on the COMP pin per the datasheet application circuit.
The 900 kHz switching frequency produces harmonic content at 1.8 MHz, 2.7 MHz, etc. that can couple into nearby analog signals. Maintain at least 10 mm of clearance between the SW node and any analog signal traces. Add an input pi-filter (10 µF + ferrite bead + 10 µF) if the ST1S10PHR is supplied from a shared rail with sensitive analog circuitry. When synchronizing to an external clock, select a frequency offset of at least 20 % from any system clock frequency (e.g., 800 kHz instead of 1 MHz) to avoid intermodulation products in the audio band.
コンプライアンス情報
RoHS and REACH compliant per STMicroelectronics product page. Not AEC-Q100 qualified - this is an industrial/consumer grade part. For automotive applications, contact STMicroelectronics for AEC-Q100 qualified variants in the same ST1S10 family.
