L7987LTR - 3A 61V Step-Down Switching Regulator | STMicroelectronics
MPN： L7987LTR ✓ 啟用中L7987LTR 概覽
A buck converter, also known as a step-down switching regulator, is a type of DC-DC converter that efficiently reduces a higher input voltage to a lower output voltage. Unlike linear regulators, which dissipate excess power as heat, buck converters use switching elements (transistors) and energy storage components (inductors and capacitors) to achieve high efficiency, often exceeding 90%. This makes them essential in power management systems where thermal constraints and battery life are critical. The L7987LTR belongs to the broader category of switching regulators, which are a subset of voltage regulators within power management ICs.
Key features of the L7987LTR include a programmable switching frequency from 250 kHz to 1 MHz, allowing designers to optimize efficiency versus component size. It offers a low quiescent current of 1.3 mA in light-load conditions, making it suitable for battery-powered applications. The device also features an internal compensation network, simplifying the design process, and includes a power-good flag for system monitoring. Its wide input voltage range of up to 61V makes it ideal for automotive systems that must withstand load-dump transients.
The L7987LTR utilizes a current-mode control architecture, providing fast transient response and stable operation over a wide range of output voltages. The integrated high-side MOSFET reduces external component count and PCB area. The device is available in a thermally enhanced HTSSOP-16 package, which offers a low thermal resistance of 40°C/W, enabling efficient heat dissipation in high-power applications.
Typical applications include industrial power supplies, automotive infotainment systems, distributed power architectures, and battery chargers. Its ability to handle high input voltages and deliver 3A output makes it a versatile choice for point-of-load regulation in harsh environments.
When designing with the L7987LTR, ensure proper PCB layout with short, low-inductance paths for the switching node and adequate copper area for thermal management. The exposed pad should be soldered to a large ground plane to maximize heat dissipation. Additionally, select an inductor with a saturation current rating above the peak switch current to avoid core saturation.
直接替換替代品，適用於 L7987LTR — 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： L7987LTR （相同外形與佔位） — 差異在於 Package, Switching Frequency, Output Voltage Range, Efficiency, Input Voltage Range.
L7987
✅ 直接替換聯絡詢價
查看資料表 →L7986TR
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →L7985
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
TPS54360
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
LT8610
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
L7987LTR 最大額定值與電氣特性
| 功能 | Step-Down (Buck) Switching Regulator |
| Output Current | 3 A |
| 輸入電壓範圍 | 4.5 V to 61 V |
| 輸出電壓範圍 | 0.6 V to VIN |
| 切換頻率 | 250 kHz to 1 MHz (programmable) |
| 靜態電流 | 1.3 mA (typical) |
| 參考電壓 | 0.6 V (typical) |
| Duty Cycle | Up to 100% |
| 效率 | Up to 90% (typical) |
| 工作溫度 | -40°C to +150°C (junction) |
| 封裝 | HTSSOP-16 (exposed pad) |
| 安裝類型 | Surface Mount |
| 熱阻，接面至環境 | 40°C/W |
| RoHS 狀態 | Compliant |
| Control Architecture | Current Mode |
| Power-Good Flag | Yes |
| Internal Compensation | Yes |
L7987LTR 腳位配置
| 腳位 1 | VIN — Input supply voltage |
| 腳位 2 | SW — Switching node output |
| 腳位 3 | GND — Ground |
| 腳位 4 | FB — Feedback voltage input |
| 腳位 5 | EN — Enable input |
| 腳位 6 | PG — Power-good flag output |
| 腳位 7 | COMP — Compensation pin (internal) |
| 腳位 8 | RT — Switching frequency programming |
| 腳位 9 | VCC — Internal supply voltage |
| 腳位 10 | GND — Ground |
| 腳位 11 | GND — Ground |
| 腳位 12 | GND — Ground |
| 腳位 13 | GND — Ground |
| 腳位 14 | GND — Ground |
| 腳位 15 | GND — Ground |
| 腳位 16 | GND — Ground |
典型應用
L7987LTR 適用於 6 應用s: Industrial Power Supplies, Automotive Infotainment Systems, Battery Chargers, Distributed Power Architectures, Telecom and Networking Equipment, LED Lighting Drivers.
Industrial Power Supplies
The L7987LTR is ideal for industrial power supplies that require a wide input voltage range and high output current. Its 4.5V to 61V input range accommodates various industrial bus voltages, while the 3A output can power sensors, actuators, and control logic. The high efficiency reduces heat generation, making it suitable for enclosed industrial enclosures. The programmable switching frequency allows optimization for EMI and component size. The device's robust design ensures reliable operation in harsh industrial environments with temperature extremes and voltage transients.
推薦
Automotive Infotainment Systems
In automotive infotainment systems, the L7987LTR provides a stable power rail for processors, displays, and audio amplifiers. Its wide input voltage range (up to 61V) handles load-dump transients, and the AEC-Q100 qualification ensures reliability in automotive environments. The 3A output current can power multiple subsystems, while the low quiescent current helps reduce battery drain when the vehicle is off. The power-good flag enables system monitoring and sequencing. The device's small HTSSOP-16 package saves PCB space in space-constrained infotainment units.
推薦
Battery Chargers
The L7987LTR can be used in battery charger circuits to step down a higher input voltage (e.g., from a solar panel or AC adapter) to the battery charging voltage. Its high efficiency minimizes power loss, and the programmable switching frequency allows optimization for EMI. The wide input range supports various power sources. The 3A output current is suitable for charging batteries in portable devices, power tools, and electric vehicles. The device's thermal performance ensures reliable operation during prolonged charging.
推薦
Distributed Power Architectures
In distributed power architectures, the L7987LTR serves as a point-of-load (POL) converter, stepping down a common intermediate bus voltage (e.g., 24V or 48V) to lower voltages for individual loads. Its wide input range and 3A output make it versatile for various POL applications. The internal compensation simplifies design, and the power-good flag enables sequencing. The device's high efficiency reduces thermal stress in dense PCB layouts. The HTSSOP-16 package with exposed pad aids heat dissipation.
推薦
Telecom and Networking Equipment
The L7987LTR is suitable for telecom and networking equipment that requires reliable power conversion from a 48V backplane. Its input voltage range of up to 61V covers the 48V nominal and transient voltages. The 3A output can power line cards, switches, and routers. The high efficiency reduces cooling requirements, and the programmable frequency helps meet EMI standards. The device's robust design ensures long-term reliability in always-on equipment.
推薦
LED Lighting Drivers
The L7987LTR can be used as a constant-voltage power supply for LED lighting systems, stepping down a high input voltage to a safe LED driver voltage. Its wide input range supports various AC/DC adapters, and the 3A output can drive multiple LED strings. The high efficiency reduces heat, and the programmable frequency allows optimization for flicker-free operation. The device's thermal performance is critical for enclosed lighting fixtures.
推薦
推薦產品摘要
工程參考資料，適用於 L7987LTR — 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 | L7987 | L7986 | L7985 | TPS54360 | LT8610 |
|---|---|---|---|---|---|---|
| Package | HTSSOP-16 | HTSSOP-16 | HTSSOP-16 | HTSSOP-16 | HTSSOP-16 | HTSSOP-16 |
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics | Texas Instruments | Analog Devices |
| Output Current | 3 A | 3 A | 2 A | 1 A | 3.5 A | 2.5 A |
| Input Voltage Range | 4.5V to 61V | 4.5V to 61V | 4.5V to 61V | 4.5V to 61V | 4.5V to 60V | 3.4V to 42V |
| Switching Frequency | 250 kHz to 1 MHz | 250 kHz to 1 MHz | 250 kHz to 1 MHz | 250 kHz to 1 MHz | 100 kHz to 2.5 MHz | 200 kHz to 2.2 MHz |
| Quiescent Current | 1.3 mA | 1.3 mA | 1.3 mA | 1.3 mA | 146 µA | 2.5 µA |
| AEC-Q100 Qualified | Yes | Yes | Yes | Yes | No | Yes |
| Internal Compensation | Yes | Yes | Yes | Yes | Yes | Yes |
主要差異化特點
- Higher output current than L7986 and L7985 (對比L7986)
- Wider input voltage range than LT8610 (對比LT8610)
- AEC-Q100 qualified, unlike TPS54360 (對比TPS54360)
設計說明
For optimal performance, place the input capacitor (10µF) and output capacitor (22µF) as close as possible to the VIN and SW pins. Use a solid ground plane and connect the exposed pad to the ground plane with multiple vias to enhance thermal dissipation. Keep the feedback trace short and away from the switching node to avoid noise coupling.
The HTSSOP-16 package has a junction-to-ambient thermal resistance of 40°C/W. At 3A output with a 12V to 5V conversion, power dissipation is approximately 21W, which would require a heatsink or forced air cooling. For typical applications with lower power dissipation, ensure adequate copper area on the PCB to keep the junction temperature below 125°C.
Do not exceed the absolute maximum input voltage of 61V. Ensure the inductor saturation current is higher than the peak switch current (typically 3.5A) to prevent core saturation. Use a Schottky diode with a voltage rating above the input voltage for the catch diode. Verify the feedback resistor divider accuracy to maintain output voltage regulation.
合規資訊
RoHS compliant and AEC-Q100 qualified per STMicroelectronics datasheet. Halogen-free status not specified in the provided data.
