LM5117MHX/NOPB - 5.5-65V Sync Buck Controller | TI
MPN： LM5117MHX/NOPB ✓ 啟用中LM5117MHX/NOPB 概覽
A synchronous buck controller is a type of DC-DC switching regulator that uses external MOSFETs to step down a higher input voltage to a lower output voltage with high efficiency. Unlike linear regulators, buck controllers achieve efficiency often above 90% by switching power devices rather than dissipating excess energy as heat. The LM5117 employs current mode control with an emulated current ramp, providing inherent line feed-forward, cycle-by-cycle current limiting, and ease of loop compensation. This control method ensures stable operation across a wide range of input voltages and load conditions.
Key features of the LM5117 include an analog current monitor output, which allows precise monitoring of the output current for system protection and telemetry. The device also features a wide 5.5V to 65V input range, programmable output voltage, and a switching frequency that can be set from 50kHz to 750kHz via an external resistor. The controller supports both high-side and low-side external N-channel MOSFETs, enabling designs with high efficiency and flexible power stage configurations.
Technically, the LM5117 integrates a high-voltage startup regulator, a precision 1.5V reference, and a robust gate drive capability. The emulated current ramp eliminates the need for a sense resistor in the high-current path, reducing power loss and improving efficiency. The device also includes features such as soft-start, hiccup mode overcurrent protection, and thermal shutdown, enhancing system reliability.
Typical applications include industrial power supplies, automotive infotainment and body electronics, telecom and networking equipment, and general-purpose step-down converters. The wide input range and high efficiency make it ideal for systems that must operate from 12V, 24V, or 48V rails with varying input transients.
When designing with the LM5117, ensure proper PCB layout with short, low-inductance paths for the high-current switching loops. The exposed pad must be soldered to a copper area for adequate thermal performance. Additionally, select the external MOSFETs and output inductor based on the required output current and efficiency targets.
直接替換替代品，適用於 LM5117MHX/NOPB — 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： LM5117MHX/NOPB （相同外形與佔位） — 差異在於 RoHS Status, Switching Frequency, Control Method, Input Voltage Range, Package.
LM5117PMHX/NOPB
✅ 直接替換📋 參考替代品（不在目錄中）
LM5117QPMH/NOPB
✅ 直接替換📋 參考替代品（不在目錄中）
LM5116MHX/NOPB
✅ 直接替換📋 參考替代品（不在目錄中）
LM5116MH/NOPB
✅ 直接替換📋 參考替代品（不在目錄中）
LM25117MHX/NOPB
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
LM5117MHX/NOPB 最大額定值與電氣特性
| 輸入電壓範圍 | 5.5V to 65V |
| 輸出電壓範圍 | 1.5V to 80V |
| Output Current | External MOSFETs (up to 20A) |
| 切換頻率 | 50kHz to 750kHz |
| Control Method | Current Mode with Emulated Ramp |
| 輸出數量 | 1 |
| 封裝 | HTSSOP-20 (PWP) |
| 工作溫度範圍 | -40°C to +125°C |
| Analog Current Monitor | Yes |
| 軟啟動 | Yes |
| 過電流保護 | Hiccup Mode |
| 過熱關機 | Yes |
| 參考電壓 | 1.5V |
| RoHS 狀態 | Compliant |
| 安裝類型 | Surface Mount |
LM5117MHX/NOPB 腳位配置
| 腳位 1 | VIN — Input supply voltage |
| 腳位 2 | VCC — Internal regulator output |
| 腳位 3 | VCCX — External VCC input |
| 腳位 4 | RT — Switching frequency set resistor |
| 腳位 5 | RAMP — Emulated ramp set |
| 腳位 6 | SS — Soft-start timing |
| 腳位 7 | COMP — Error amplifier output |
| 腳位 8 | FB — Feedback input |
| 腳位 9 | CS — Current sense input |
| 腳位 10 | CM — Current monitor output |
| 腳位 11 | AGND — Analog ground |
| 腳位 12 | PGND — Power ground |
| 腳位 13 | HO — High-side gate drive |
| 腳位 14 | HB — High-side bootstrap |
| 腳位 15 | SW — Switch node |
| 腳位 16 | LO — Low-side gate drive |
| 腳位 17 | VCC — Internal regulator output |
| 腳位 18 | EN — Enable input |
| 腳位 19 | UVLO — Under-voltage lockout set |
| 腳位 20 | PAD — Exposed thermal pad |
典型應用
LM5117MHX/NOPB 適用於 6 應用s: Industrial Power Supplies, Automotive Infotainment, Telecom and Networking Equipment, General-Purpose Step-Down Converters, Battery-Powered Systems, LED Lighting Drivers.
Industrial Power Supplies
The LM5117MHX/NOPB is ideal for industrial power supplies due to its wide 5.5V to 65V input range and high efficiency. It can step down from 24V or 48V rails to lower voltages with minimal heat dissipation. The analog current monitor enables precise load monitoring for system protection. With switching frequencies up to 750kHz, it allows compact magnetics, reducing board space in industrial control systems.
推薦
Automotive Infotainment
In automotive infotainment systems, the LM5117MHX/NOPB provides a robust power solution from the 12V battery or 24V truck systems. Its wide input range handles load dumps and cold crank transients. The -40°C to +125°C operating range ensures reliability in harsh environments. The current monitor can be used for diagnostic functions, detecting overcurrent conditions in audio amplifiers or displays.
推薦
Telecom and Networking Equipment
Telecom equipment often operates from 48V backplane rails. The LM5117MHX/NOPB efficiently steps down 48V to 3.3V or 5V for logic and interface circuits. Its current mode control provides excellent line and load transient response, crucial for maintaining stable voltages during data bursts. The high switching frequency reduces the size of output filters, saving valuable board space in dense networking hardware.
推薦
General-Purpose Step-Down Converters
The LM5117MHX/NOPB serves as a flexible building block for general-purpose step-down converters. Designers can configure output voltage from 1.5V to 80V and output current from a few amps to over 20A by selecting appropriate external components. The emulated current ramp eliminates the need for a sense resistor, simplifying layout and improving efficiency. This makes it suitable for a wide range of prototyping and production designs.
推薦
Battery-Powered Systems
In battery-powered systems, the LM5117MHX/NOPB efficiently regulates voltage from a battery that can vary from 5.5V to 65V. Its high efficiency extends battery life, and the low quiescent current in standby modes helps meet energy regulations. The analog current monitor can be used for fuel gauging or to detect low battery conditions. The wide input range accommodates multiple battery cells in series.
推薦
LED Lighting Drivers
The LM5117MHX/NOPB can be configured as a constant-current LED driver by using the analog current monitor to sense and regulate LED current. Its wide input range supports various LED string voltages, and the high switching frequency allows small inductors, reducing fixture size. The hiccup mode overcurrent protection prevents damage during LED faults. This makes it suitable for industrial and automotive LED lighting.
推薦
推薦產品摘要
工程參考資料，適用於 LM5117MHX/NOPB — 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 | LM5117PMHX/NOPB | LM5117QPMH/NOPB | LM5116MHX/NOPB |
|---|---|---|---|---|
| Package | HTSSOP-20 (PWP) | HTSSOP-20 (PWP) | HTSSOP-20 (PWP) | HTSSOP-20 (PWP) |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Input Voltage Range | 5.5V to 65V | 5.5V to 65V | 5.5V to 65V | 5.5V to 65V |
| Switching Frequency | 50kHz to 750kHz | 50kHz to 750kHz | 50kHz to 750kHz | 50kHz to 750kHz |
| Analog Current Monitor | Yes | Yes | Yes | No |
| Automotive Grade | No | No | Yes (AEC-Q100) | No |
| Operating Temperature Range | -40°C to +125°C | -40°C to +125°C | -40°C to +125°C | -40°C to +125°C |
| Control Method | Current Mode with Emulated Ramp | Current Mode with Emulated Ramp | Current Mode with Emulated Ramp | Current Mode with Emulated Ramp |
主要差異化特點
- Analog current monitor output (對比LM5116MHX/NOPB)
- Wide input voltage range up to 65V (對比LM5116MHX/NOPB)
- Automotive-grade variant available (對比LM5117PMHX/NOPB)
設計說明
For optimal performance, place the input capacitor, high-side MOSFET, low-side MOSFET, and output inductor in a tight loop to minimize parasitic inductance. The switch node (SW) should have a small copper area to reduce EMI. Use a solid ground plane and connect the exposed pad (PAD) to the ground plane with multiple vias for thermal relief.
The LM5117MHX/NOPB itself dissipates minimal power, but the external MOSFETs and inductor generate heat. Ensure adequate copper area and airflow for these components. The exposed pad must be soldered to a large copper pour to keep the controller cool. For high-current designs, consider using a heatsink on the MOSFETs.
Avoid using a sense resistor in the high-current path; the emulated current ramp eliminates this need. Ensure the bootstrap capacitor (HB) is placed close to the HO and SW pins. Do not exceed the absolute maximum ratings on VIN or SW. Use a proper UVLO resistor divider to prevent operation below the minimum input voltage.
合規資訊
RoHS compliant per TI product page. Not AEC-Q100 qualified; use LM5117QPMH/NOPB for automotive.
