STPM066S - 66V Step-Down DC-DC Converter | STMicroelectronics
MPN： STPM066S ✓ 啟用中STPM066S 概覽
A step-down DC-DC converter, also known as a buck converter, is a type of switching regulator that efficiently reduces a higher input voltage to a lower output voltage. Unlike linear regulators, which dissipate excess power as heat, buck converters use inductive energy storage and high-frequency switching to achieve efficiencies often exceeding 90%. This makes them essential in power management systems where thermal budget and battery life are critical. The STPM066S belongs to the broader category of power management ICs, specifically within DC-DC converters, and is a key building block in distributed power architectures.
Key features of the STPM066S include a peak efficiency of 95%, a switching frequency adjustable from 200kHz to 2.2MHz, and a low quiescent current of 40uA in light-load mode. The device also offers a precision enable pin with hysteresis, soft-start to limit inrush current, and comprehensive protection features including overcurrent, overvoltage, and thermal shutdown. The integrated MOSFETs have low RDS(on) of 80mOhm (high-side) and 40mOhm (low-side), minimizing conduction losses.
Technically, the STPM066S employs a current-mode control architecture, providing fast transient response and stable operation with a wide range of output capacitors. The adjustable switching frequency allows designers to optimize efficiency versus component size, while the external compensation pin offers flexibility in loop tuning. The device is available in a QFN-16 package with an exposed thermal pad, achieving a thermal resistance of 25°C/W, enabling reliable operation at high ambient temperatures.
Typical applications include industrial power supplies, automotive infotainment systems, battery-powered equipment, and distributed power architectures in telecom and networking equipment. The wide input range and high efficiency make it ideal for pre-regulation in multi-rail systems, where it steps down a high-voltage bus to an intermediate rail for downstream LDOs or point-of-load converters.
When designing with the STPM066S, ensure proper input and output capacitor selection to minimize voltage ripple and maintain stability. The bootstrap capacitor for the high-side driver must be placed close to the BST pin, and the feedback network should be routed away from the inductor to avoid noise coupling. Adequate copper pour on the thermal pad is essential for heat dissipation at high output currents.
直接替換替代品，適用於 STPM066S — 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。
STPM066
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
STPM066S-Q1
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
LT8640
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
STPM066S 最大額定值與電氣特性
| 輸入電壓範圍 | 4.5 V to 66 V |
| 輸出電壓範圍 | 0.8 V to 60 V |
| 最大輸出電流 | 3 A |
| Peak Efficiency | 95% |
| 切換頻率 | 200 kHz to 2.2 MHz |
| 靜態電流 | 40 uA (light load) |
| High-Side RDS(on) | 80 mOhm |
| Low-Side RDS(on) | 40 mOhm |
| Control Architecture | Current Mode |
| 封裝 | QFN-16 (4x4 mm) |
| 熱阻 | 25 C/W |
| 工作溫度 | -40C to +125C |
| 致能腳位 | Yes (with hysteresis) |
| 軟啟動 | Internal |
| Protection Features | OCP, OVP, Thermal Shutdown |
| RoHS 狀態 | Compliant |
STPM066S 腳位配置
| 腳位 1 | BST — Bootstrap capacitor connection for high-side driver |
| 腳位 2 | SW — Switch node output |
| 腳位 3 | GND — Ground |
| 腳位 4 | GND — Ground |
| 腳位 5 | FB — Feedback voltage input |
| 腳位 6 | COMP — Compensation network connection |
| 腳位 7 | EN — Enable input (active high) |
| 腳位 8 | VIN — Input supply voltage |
| 腳位 9 | VIN — Input supply voltage |
| 腳位 10 | GND — Ground |
| 腳位 11 | GND — Ground |
| 腳位 12 | VOUT — Output voltage |
| 腳位 13 | VOUT — Output voltage |
| 腳位 14 | GND — Ground |
| 腳位 15 | GND — Ground |
| 腳位 16 | PAD — Exposed thermal pad (ground) |
典型應用
STPM066S 適用於 6 應用s: Industrial Power Supplies, Automotive Infotainment, Battery-Powered Equipment, Telecom and Networking, Medical Devices, LED Lighting.
Industrial Power Supplies
The STPM066S is ideal for industrial power supplies that require a wide input voltage range and high efficiency. Its 4.5V to 66V input range accommodates 24V and 48V industrial bus systems, while the 3A output current can power sensors, actuators, and control logic. The high efficiency reduces heat dissipation, enabling compact enclosures without active cooling. In a typical industrial power supply, the STPM066S steps down a 48V bus to a 5V or 3.3V rail for microcontrollers and communication interfaces. The adjustable switching frequency allows optimization for EMI compliance, and the integrated protection features ensure reliable operation in harsh environments. The low quiescent current is beneficial for always-on systems that need to minimize standby power consumption.
推薦
Automotive Infotainment
In automotive infotainment systems, the STPM066S provides a robust power solution for head units, displays, and audio amplifiers. The wide input range handles load-dump transients up to 66V, and the -40°C to +125°C operating range ensures reliability in extreme temperatures. The 3A output current can power multiple rails, such as 5V for USB ports and 3.3V for application processors. The high efficiency minimizes heat in the dashboard, and the low quiescent current helps reduce battery drain when the vehicle is off. The STPM066S can be used in a pre-regulator configuration, stepping down the 12V battery voltage to an intermediate rail for downstream LDOs, ensuring clean power for sensitive audio and video components.
推薦
Battery-Powered Equipment
The STPM066S is well-suited for battery-powered equipment such as portable instruments, IoT devices, and wireless sensors. Its high efficiency (up to 95%) and low quiescent current (40uA) extend battery life, making it ideal for applications where power consumption is critical. The wide input range allows operation from multi-cell battery packs (e.g., 2S to 8S Li-ion) without additional regulation. In a typical IoT sensor node, the STPM066S steps down a 12V battery to 3.3V for the microcontroller and wireless transceiver. The light-load mode maintains high efficiency at low currents, and the enable pin allows power gating to further reduce standby power. The compact QFN-16 package saves board space in space-constrained designs.
推薦
Telecom and Networking
In telecom and networking equipment, the STPM066S provides efficient power conversion for routers, switches, and base stations. The wide input range supports 48V telecom bus systems, and the 3A output current can power line cards, FPGAs, and ASICs. The high efficiency reduces cooling requirements in densely packed racks, and the adjustable switching frequency allows synchronization to avoid interference with communication signals. The STPM066S can be used in a distributed power architecture, stepping down a 48V bus to an intermediate 12V rail, which is then converted to lower voltages by point-of-load converters. The integrated protection features ensure reliable operation in mission-critical applications.
推薦
Medical Devices
The STPM066S is suitable for medical devices that require reliable and efficient power conversion. Its wide input range and high efficiency make it ideal for battery-powered portable medical equipment, such as patient monitors and infusion pumps. The low quiescent current extends battery life, and the integrated protection features ensure safe operation. In a typical patient monitor, the STPM066S steps down a 12V battery to 5V for the display and 3.3V for the microcontroller. The adjustable switching frequency allows optimization for EMI compliance, which is critical in medical environments. The compact package and high thermal performance enable reliable operation in compact enclosures.
推薦
LED Lighting
The STPM066S can be used in LED lighting applications to provide a constant voltage supply for LED drivers. Its wide input range supports various AC/DC adapter outputs, and the high efficiency reduces heat in the lighting fixture. The 3A output current can power multiple LED strings, and the adjustable output voltage allows precise control of the LED current via a constant-current driver. In a typical LED lighting system, the STPM066S steps down a 24V supply to 12V for the LED driver, which then regulates the current to the LEDs. The low quiescent current is beneficial for standby modes, and the protection features ensure safe operation in case of LED faults.
推薦
推薦產品摘要
工程參考資料，適用於 STPM066S — 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 | STPM066 | STPM066S-Q1 | TPS54360 | LT8640 |
|---|---|---|---|---|---|
| Package | QFN-16 (4x4 mm) | QFN-16 (4x4 mm) - same | QFN-16 (4x4 mm) - same | SOIC-8 - different | QFN-16 (4x4 mm) - same |
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics | Texas Instruments | Analog Devices |
| Input Voltage Range | 4.5V to 66V | 4.5V to 66V | 4.5V to 66V | 4.5V to 60V | 3.4V to 42V |
| Output Current | 3A | 3A | 3A | 3.5A | 5A |
| Peak Efficiency | 95% | 95% | 95% | 92% | 96% |
| Switching Frequency | 200kHz to 2.2MHz | 200kHz to 2.2MHz | 200kHz to 2.2MHz | 100kHz to 2.5MHz | 200kHz to 2.2MHz |
| Quiescent Current | 40uA | 40uA | 40uA | 146uA | 2.5uA |
| Automotive Grade | No | No | Yes (AEC-Q100) | No | No |
主要差異化特點
- Wide input voltage range up to 66V (對比LT8640)
- Automotive grade option available (對比TPS54360)
- Low quiescent current of 40uA (對比TPS54360)
設計說明
Place the input capacitor (10uF ceramic) as close as possible to the VIN and GND pins to minimize input voltage ripple and reduce EMI. The output capacitor (22uF ceramic) should be placed near the VOUT and GND pins. Use a 0.1uF bootstrap capacitor between BST and SW pins, placed within 5mm of the IC. Ensure the exposed thermal pad is soldered to a large copper pour for heat dissipation.
At VIN=24V, VOUT=5V, and 3A load, the power dissipation is approximately 3.6W (assuming 85% efficiency). With a thermal resistance of 25°C/W, the junction temperature rise is 90°C above ambient. For reliable operation at high ambient temperatures, provide at least 1 square inch of copper on the thermal pad layer and consider adding thermal vias to the ground plane.
Do not exceed the absolute maximum input voltage of 66V. Ensure the feedback resistor divider uses 1% tolerance resistors to maintain output voltage accuracy. The compensation network (COMP pin) must be tuned for the selected output capacitor and switching frequency to ensure stability. Avoid routing the feedback trace near the inductor or switch node to prevent noise coupling.
合規資訊
RoHS compliant per STMicroelectronics product page. Not AEC-Q100 qualified for standard version; choose STPM066S-Q1 for automotive.
