L7987LTR - 3A 61V Step-Down Switching Regulator | STMicroelectronics
料号： L7987LTR ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $2.7728 | $2.77 |
L7987LTR 概述
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.
直接替换替代料： L7987LTR ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： L7987LTR （相同外形与封装尺寸） ——差异在于 Package, Switching Frequency, Output Voltage Range, Efficiency, Input Voltage Range.
快速对比工具——选择替代料号进行并排对比：
L7987
✅ 直接替换✓ 有现货
$1.31 / 个
查看数据手册 →L7986TR
✅ 直接替换 ⚠️ 规格未核验✓ 有现货
$1.85 / 个
查看数据手册 →L7985
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
TPS54360
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
LT8610
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
L7987LTR 最大额定值与电气特性
| 功能 | Step-Down (Buck) Switching Regulator |
| Output Current | 3 A |
| 输入电压范围 | 4.5 V to 61 V |
| 输出电压范围 | 0.6 V to VIN |
| 开关频率 | 250 kHz to 1 MHz (programmable) |
| 静态电流 | 1.3 mA (typical) |
| 基准电压 | 0.6 V (typical) |
| Duty Cycle | Up to 100% |
| 效率 | Up to 90% (typical) |
| 工作温度 | -40°C to +150°C (junction) |
| 封装 | HTSSOP-16 (exposed pad) |
| 安装类型 | Surface Mount |
| 热阻，结到环境 | 40°C/W |
| RoHS 状态 | Compliant |
| Control Architecture | Current Mode |
| Power-Good Flag | Yes |
| Internal Compensation | Yes |
L7987LTR 引脚配置
| 引脚 1 | VIN — Input supply voltage |
| 引脚 2 | SW — Switching node output |
| 引脚 3 | GND — Ground |
| 引脚 4 | FB — Feedback voltage input |
| 引脚 5 | EN — Enable input |
| 引脚 6 | PG — Power-good flag output |
| 引脚 7 | COMP — Compensation pin (internal) |
| 引脚 8 | RT — Switching frequency programming |
| 引脚 9 | VCC — Internal supply voltage |
| 引脚 10 | GND — Ground |
| 引脚 11 | GND — Ground |
| 引脚 12 | GND — Ground |
| 引脚 13 | GND — Ground |
| 引脚 14 | GND — Ground |
| 引脚 15 | GND — Ground |
| 引脚 16 | GND — Ground |
典型应用
L7987LTR 适用于 6 应用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.
推荐
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.
推荐
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.
推荐
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.
推荐
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.
推荐
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.
推荐
推荐产品汇总
工程参考数据： L7987LTR ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | 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 |
关键差异点
- Higher output current than L7986 and L7985 （对比 L7986)
- Wider input voltage range than LT8610 （对比 LT8610)
- AEC-Q100 qualified, unlike TPS54360 （对比 TPS54360)
设计说明
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.
合规信息
RoHS compliant and AEC-Q100 qualified per STMicroelectronics datasheet. Halogen-free status not specified in the provided data.
