L7987LTR - 3A 61V Step-Down Switching Regulator | STMicroelectronics
MPN: L7987LTR ✓ Hoạt độngL7987LTR Tóm tắt
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.
Bộ thay thế dễ dàng lắp đặt cho L7987LTR — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
Các biến thể trong loạt này
Các mẫu cùng loạt có thể lắp đặt dễ dàng tương thích với L7987LTR (cùng hình factor và footprint) — khác nhau ở Package, Switching Frequency, Output Voltage Range, Efficiency, Input Voltage Range.
L7987
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →L7986TR
✅ Drop-In ⚠️ Thông số chưa được xác minhLiên hệ để biết giá
Xem tài liệu →L7985
✅ Drop-In ⚠️ Thông số chưa được xác minh📋 Tham chiếu thay thế (không có trong danh mục)
TPS54360
✅ Drop-In ⚠️ Thông số chưa được xác minh📋 Tham chiếu thay thế (không có trong danh mục)
LT8610
✅ Drop-In ⚠️ Thông số chưa được xác minh📋 Tham chiếu thay thế (không có trong danh mục)
L7987LTR Tỷ lệ tối đa & tính chất điện
| Chức năng | Step-Down (Buck) Switching Regulator |
| Output Current | 3 A |
| Phạm vi điện áp đầu vào | 4.5 V to 61 V |
| Khoảng điện áp đầu ra | 0.6 V to VIN |
| Tần số chuyển đổi | 250 kHz to 1 MHz (programmable) |
| Điện áp yên tĩnh | 1.3 mA (typical) |
| Điện áp tham chiếu | 0.6 V (typical) |
| Duty Cycle | Up to 100% |
| Hiệu suất | Up to 90% (typical) |
| Nhiệt độ hoạt động | -40°C to +150°C (junction) |
| Hộp | HTSSOP-16 (exposed pad) |
| Kiểu lắp đặt | Surface Mount |
| Kháng nhiệt, mối nối đến môi trường | 40°C/W |
| Trạng thái RoHS | Compliant |
| Control Architecture | Current Mode |
| Power-Good Flag | Yes |
| Internal Compensation | Yes |
Cấu hình chân L7987LTR
| Chân 1 | VIN — Input supply voltage |
| Chân 2 | SW — Switching node output |
| Chân 3 | GND — Ground |
| Chân 4 | FB — Feedback voltage input |
| Chân 5 | EN — Enable input |
| Chân 6 | PG — Power-good flag output |
| Chân 7 | COMP — Compensation pin (internal) |
| Chân 8 | RT — Switching frequency programming |
| Chân 9 | VCC — Internal supply voltage |
| Chân 10 | GND — Ground |
| Chân 11 | GND — Ground |
| Chân 12 | GND — Ground |
| Chân 13 | GND — Ground |
| Chân 14 | GND — Ground |
| Chân 15 | GND — Ground |
| Chân 16 | GND — Ground |
Ứng dụng tiêu biểu
L7987LTR phù hợp cho 6 Áp dụngs: 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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho L7987LTR — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | 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 |
Bảo phân biệt quan trọng
- Higher output current than L7986 and L7985 (vsL7986)
- Wider input voltage range than LT8610 (vsLT8610)
- AEC-Q100 qualified, unlike TPS54360 (vsTPS54360)
Ghi chú thiết kế
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.
Thông tin tuân thủ
RoHS compliant and AEC-Q100 qualified per STMicroelectronics datasheet. Halogen-free status not specified in the provided data.
