具有 Eco-mode™ 的 TPS54540 4.5V 至 42V 输入、5A 降压直流/直流转换器

1 特性

• 轻负载条件下使用脉冲跳跃实现的高效率 Eco-mode。™
• 92mΩ 高侧金属氧化物半导体场效应晶体管 (MOSFET)
• 146μA 静态运行电流和
  2μA 关断电流
• 100kHz 至 2.5MHz 的固定开关频率
• 同步至外部时钟
• 轻负载条件下使用集成型引导 (BOOT) 再充电场效应晶体管 (FET) 实现的低压降
• 可调欠压闭锁 (UVLO) 电压和滞后
• 0.8V 1% 内部电压基准
• 8 引脚 HSOP，带有 PowerPAD™的封装
• -40°C 至 150°C T_J 运行范围
• 使用 TPS54540 并借助 WEBENCH® 电源设计器创建定制设计方案增加了 WEBENCH 信息

2 应用

• 工业自动化和电机控制
• 车辆配件：全球卫星定位系统 (GPS)，娱乐系统
• USB 专用充电端口和电池充电器
• 12V 和 24V 工业、汽车和通信电源系统

3 说明

TPS54540 是一款 42V，5A，降压稳压器，此稳压器具有一个集成的高侧 MOSFET。按照 ISO 7637 标准，此器件能够耐受高达 45V 的抛负载脉冲。电流模式控制提供了简单的外部补偿和灵活的组件选择。一个低纹波脉冲跳跃模式将无负载时的电源电流减小至 146μA。当启用引脚被拉至低电平时，关断电源电流被减少至 2μA。

欠压闭锁在内部设定为 4.3V，但可用使能引脚将之提高。输出电压启动斜升由内部控制以提供一个受控的启动并且消除过冲。

宽开关频率范围可实现对效率或者外部组件尺寸的优化。输出电流是受限的逐周期电流。频率折返和热关断在过载条件下保护内部和外部组件。

TPS54540 可提供 8 引脚热增强型 HSOP PowerPAD™ 封装。

空白

简化电路原理图

效率与负载电流间的关系

4 修订历史记录

Changes from A Revision (March 2014) to B Revision

• 在特性、详细设计流程和器件支持部分Go
• Changed the Handling Ratings table To ESD Ratings tableGo
• Changed V_IN MIN Value From: 4.5 V To: V_O + V_DO, and added Note 1 in the Recommended Operating ConditionsGo
• Deleted last graph: "5 V Start and Stop Voltage" from the Typical CharacteristicsGo
• Updated text and added Equation 1 in the Low Dropout Operation and Bootstrap Voltage (BOOT) Go
• Deleted text: "The start and stop voltage for a typical 5 V..." from the Low Dropout Operation and Bootstrap Voltage (BOOT) sectionGo
• Changed Equation 7 and Equation 8. Go
• Changed Equation 27 Go
• Added new section: Minimum V_INGo
• Deleted 2 graphs named "Low Dropout Operation" from the Application Curves section Go

Changes from * Revision (May 2013) to A Revision

• 增加了器件信息表、推荐运行条件表、引脚配置和功能部分、处理额定值表、特性 说明部分、器件功能模式、应用和实施部分、电源相关建议部分、布局部分、器件和文档支持部分以及机械、封装和可订购信息部分。Go
• Changed the Electrical Characteristics Conditions From: VIN = 4.5 to 60 V To: VIN = 4.5 to 42 VGo
• Changed the Operating: nonswitching supply current TEST CONDITIONS From: FB = 0.83 V To: FB = 0.9 VGo
• Changed RT/CLK high threshold MAX value From: 1.7 V To: 2 V Go
• Changed the title of graph "5 V Start and Stop Voltage" to include a link to the Low Dropout Operation section. Go
• Changed the FBD, removed the Logic block and Shutdown signal from the OV comparatorGo
• Changed VF = Forward Drop of the Catch Diode To: V_D = Forward Drop of the Catch Diode Go
• Deleted value TSW = 1 / Fsw from the list following Equation 2Go
• Changed VB2SW = VBOOT + VF To: VB2SW = VBOOT + V_DGo
• Changed VBOOT = (1.41 x V_IN - 0.554 - VF / TSW - 1.847 x 10³ x IB2SW) / (1.41 + 1 / Tsw) To: VBOOT = (1.41 x V_IN - 0.554 - V_D x ƒ_SW - 1.847 x 10³ x IB2SW) / (1.41 + ƒ_SW)Go
• Deleted figure: "5V Start/Stop Voltage"Go
• Added a title to Figure 23Go
• Changed the section title From: Selecting the Switching Frequency To: Accurate Current Limit Operation and Maximum Switching FrequencyGo
• Changed text in the Synchronization to RT/CLK terminal section From: "0.5 V and higher than 1.7 V" To: "0.5 V and higher than 2 V" Go
• Changed Equation 33 From: (5.13V² - 5 V²) To: 3.43 V² - 3.3 V²)Go
• Changed Figure 36, VOUT From: 200 mV/div To 100 mV/div Go
• Changed Figure 38 , EN From: 1 V/div To: 2 V/div, VOUT From: 4 V/div To: 2 V/div, and Time = 2 ms/div To: Time = 20 ms/divGo
• Changed Figure 39 , VOUT From: 4 V/div To: 2 V/divGo

5 Pin Configuration and Functions

HSOIC Package

(Top View)