Intersil公司的ISL8013A是一款高效率，單片同步降壓型DC-DC轉換器，可提供高達3A的連續(xù)輸出電流從2.8V至5.5V的輸入電源。它采用了電流控制架構，以提供非常低的占空比工作在高頻率快速瞬態(tài)響應和卓越的環(huán)路穩(wěn)定性。ISL8013A集成了一對低導通電阻的P溝道和N-通道內部MOSFET，以最大限度地提高效率和減少外部元件數(shù)量。100％占空比工作，允許小于300mV壓差電壓，輸出電流為3A。ISL8013AEVAL2Z是基于ISL8013A芯片開發(fā)設計的參考方案。ISL8013AEVAL2Z開發(fā)套件應用于單負載點的設備，設備電壓應用范圍為2.7V-5.5V。ISL8013AEVAL2Z評估開發(fā)板主要用于展示ISL8013A低靜態(tài)電流模式下的轉換性能。本文主要介紹ISL8013A芯片簡介、主要特性、應用及其內部框圖。對于ISL8013AEVAL2Z參考方案，主要介紹參考方案的主要特性、原理圖、元器件清單及其PCB Layout圖。
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應用：
• 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
圖1. ISL8013A內部方框圖
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原理圖：
圖2. ISL8013AEVAL2Z原理圖
ISL8013AEVAL2Z元器件清單：
PCB Layout圖：
  
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