ZHCSLO5B December 2020 – December 2021 LM25149
PRODUCTION DATA
- 1 特性
- 2 應用
- 3 說明
- 4 Revision History
- 5 說明（續）
- 6 Pin Configuration and Functions
- 7 Specifications
-
8 Detailed Description
- 8.1 Overview
- 8.2 Functional Block Diagram
- 8.3
Feature Description
- 8.3.1 Input Voltage Range (VIN)
- 8.3.2 High-Voltage Bias Supply Regulator (VCC, VCCX, VDDA)
- 8.3.3 Precision Enable (EN)
- 8.3.4 Power-Good Monitor (PG)
- 8.3.5 Switching Frequency (RT)
- 8.3.6 Active EMI Filter
- 8.3.7 Dual Random Spread Spectrum (DRSS)
- 8.3.8 Soft Start
- 8.3.9 Output Voltage Setpoint (FB)
- 8.3.10 Minimum Controllable On Time
- 8.3.11 Error Amplifier and PWM Comparator (FB, EXTCOMP)
- 8.3.12 Slope Compensation
- 8.3.13 Inductor Current Sense (ISNS+, VOUT)
- 8.3.14 Hiccup Mode Current Limiting
- 8.3.15 High-Side and Low-Side Gate Drivers (HO, LO)
- 8.3.16 Output Configurations (CNFG)
- 8.3.17 Single-Output Dual-Phase Operation
- 8.4 Device Functional Modes
-
9 Application and Implementation
- 9.1 Application Information
- 9.2
Typical Applications
- 9.2.1
Design 1 – High Efficiency 2.1-MHz Synchronous
Buck Regulator
- 9.2.1.1 Design Requirements
- 9.2.1.2
Detailed Design Procedure
- 9.2.1.2.1 Custom Design With WEBENCH? Tools
- 9.2.1.2.2 Custom Design With Excel Quickstart Tool
- 9.2.1.2.3 Buck Inductor
- 9.2.1.2.4 Current-Sense Resistance
- 9.2.1.2.5 Output Capacitors
- 9.2.1.2.6 Input Capacitors
- 9.2.1.2.7 Frequency Set Resistor
- 9.2.1.2.8 Feedback Resistors
- 9.2.1.2.9 Compensation Components
- 9.2.1.2.10 Active EMI Components
- 9.2.1.3 Application Curves
- 9.2.2 Design 2 – High Efficiency 440-kHz Synchronous Buck Regulator
- 9.2.3 Design 3 – Dual-Phase 400-kHz 20-A Synchronous Buck Regulator
- 9.2.1
Design 1 – High Efficiency 2.1-MHz Synchronous
Buck Regulator
- 10Power Supply Recommendations
- 11Layout
- 12Device and Documentation Support
- 13Mechanical, Packaging, and Orderable Information
3 說明
LM25149 是一款 42V 超低 IQ 同步降壓直流/直流控制器，適合高電流單輸出應用。該控制器使用峰值電流模式控制架構，可實現簡單環路補償、快速瞬態響應和出色的負載和線路調節性能。LM25149 可設置為以交錯雙相模式運行，實現精確的電流共享，適合高電流應用。它可在低至 3.5V 的 VIN 和接近 100% 的占空比（如果需要）下運行。
LM25149 有兩個獨特的 EMI 降低特性：有源 EMI 濾波器和雙隨機展頻 (DRSS)。有源 EMI 濾波器可檢測直流輸入總線上的任何噪聲或紋波電壓，并注入異相消除信號以減少干擾。DRSS 將低頻三角調制與高頻隨機調制相結合，可分別在低頻和高頻頻帶上降低 EMI。此項混合技術符合業界通用的 EMC 測試中指定的多種分辨率帶寬 (RBW) 設置。
器件信息
| 器件型號 | 封裝(1) | 封裝尺寸（標稱值） |
|---|---|---|
| LM25149 | VQFN (24) | 3.5mm × 5.5mm |
(1) 如需了解所有可用封裝，請參閱數據表末尾的可訂購產品附錄
典型應用原理圖
CISPR 25 EMI 性能 150kHz 至 30MHz