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Intersil公司的ISL8013A是一款高效率，单片同步降压型DC-DC转换器，可提供高达3A的连续输出电流从2.8V至5.5V的输入电源。它采用了电流控制架构，以提供非常低的占空比工作在高频率快速瞬态响应和卓越的环路稳定性。ISL8013A集成了一对低导通电阻的P沟道和N-通道内部MOSFET，以最大限度地提高效率和减少外部元件数量。100％占空比工作，允许小于300mV压差电压，输出电流为3A。ISL8013AEVAL2Z是基于ISL8013A芯片开发设计的参考方案。ISL8013AEVAL2Z开发套件应用于单负载点的设备，设备电压应用范围为2.7V-5.5V。ISL8013AEVAL2Z评估开发板主要用于展示ISL8013A低静态电流模式下的转换性能。本文主要介绍ISL8013A芯片简介、主要特性、应用及其内部框图。对于ISL8013AEVAL2Z参考方案，主要介绍参考方案的主要特性、原理图、元器件清单及其PCB Layout图。
The ISL8013A is a high efficiency, monolithic,synchronous step-down DC/DC converter that can deliver up to 3A continuous output current from a 2.8V to 5.5V input supply. It uses a current control architecture to deliver very low duty cycle operation at high frequency with fast transient response and excellent loop stability.
The ISL8013A integrates a pair of low ON-resistance P-Channel and N-Channel internal MOSFETs to maximize efficiency and minimize external component count. The 100% duty-cycle operation allows less than 300mV dropout voltage at 3A output current. High 1MHz pulse-width modulation (PWM) switching frequency allows the use of small external components and SYNC input enables multiple ICs to synchronize out of phase to reduce ripple and eliminate beat frequencies.
The ISL8013A can be configured for discontinuous or forced continuous operation at light load. Forced continuous operation reduces noise and RF interference while discontinuous mode provides high efficiency by reducing switching losses at light loads.
Fault protection is provided by internal hiccup mode current limiting during short circuit and overcurrent conditions, an output over voltage comparator and over-temperature monitor circuit. A power good output voltage monitor indicates when the output is in regulation.
The ISL8013A is offered in a space saving 4x4 QFN lead free package with exposed pad lead frames for low thermal resistance.
The ISL8013A includes a pair of low ON-resistance P-Channel and N-Channel internal MOSFETs to maximize efficiency and minimize external component count. The 100% duty-cycle operation allows less than 300mV dropout voltage at 3A.
The ISL8013A offers a 1ms Power Good (PG) timer at power-up. When shutdown, ISL8013A discharges the output capacitor. Other features include internal soft-start, internal compensation, overcurrent protection, and thermal shutdown.
The ISL8013A is offered in a 4mmx4mm 16 Ld QFN package with 1mm maximum height. The complete converter occupies less than 0.4in2 area.
ISL8013A主要特性：
• High Efficiency Synchronous Buck Regulator with up to 97% Efficiency
• Power-Good (PG) Output with a 1ms Delay
• 2.8V to 5.5V Supply Voltage
• 3% Output Accuracy Over-Temperature/Load/Line
• 3A Output Current
• Start-Up with Pre-Biased Output
• Internal Soft-Start - 1ms
• Soft-Stop Output Discharge During Disabled
• 35μA Quiescent Supply Current in PFM Mode
• Selectable Forced PWM Mode and PFM Mode
• External Synchronization up to 4MHz
• Less than 1μA Logic Controlled Shutdown Current
• 100% Maximum Duty Cycle
• Internal Current Mode Compensation
• Peak Current Limiting and Hiccup Mode Short Circuit Protection
• Over-Temperature Protection
• Small 16 Ld 4mmx4mm QFN
• Pb-Free (RoHS Compliant)
ISL8013A应用：
• DC/DC POL Modules
• μC/μP, FPGA and DSP Power
• Plug-in DC/DC Modules for Routers and Switchers
• Portable Instruments
• Test and Measurement Systems
• Li-ion Battery Powered Devices
• Small Form Factor (SFP) Modules
• Bar Code Readers
图1. ISL8013A内部方框图
ISL8013AEVAL2Z主要特性：
• High Efficiency Synchronous Buck Regulator with up to 95% Efficiency
• Power-Good (PG) Output with 1ms Delay
• 2.7V to 5.5V Supply Voltage
• 3% Output Accuracy Over-Temperature/Load/Line
• 3A Guaranteed Output Current
• Start-up with Pre-biased Output
• Internal Digital Soft-Start - 1ms
• Soft-Stop Output Discharge During Disabled
• 35μA Quiescent Supply Current in PFM Mode
• Selectable Forced PWM Mode and PFM Mode
• External Synchronization up to 4MHz
• Less than 1μA Logic Controlled Shutdown Current
• 100% Maximum Duty Cycle for Lowest Dropout
• Internal Current Mode Compensation
• Peak Current Limiting and Hiccup Mode Short Circuit Protection
• Over-Temperature Protection
ISL8013AEVAL2Z原理图：
图2. ISL8013AEVAL2Z原理图
ISL8013AEVAL2Z元器件清单：
PCB Layout图：
  
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