Fairchild FAN2108 8A高效降压电源方案

Fairchild公司的FAN2108是 8A高效同步降压TinyBuck电源稳压器,包括有两个同步MOSFET和控制器/驱动器.输入电压从3V到24V, 输出电压从0.8V 到80% VIN,输出电流达8A.可编程的工作频率从200KHz 到600KHz,峰值效率高达95%.主要应用在服务器,点负载稳压,高端计算系统,图像卡,以电池为能源的设备和机顶盒.本文介绍了FAN2108的主要特性,方框图, 典型应用电路图以及输出电压1.8V时的典型应用电路图.

FAN2108 — TinyBuck:3-24V Input, 8A, High-Efficiency, Integrated Synchronous Buck Regulator

The FAN2108 TinyBuck™ is a highly efficient, small footprint, 8A, synchronous buck regulator. The FAN2108 contains both synchronous MOSFETs and a controller/driver with optimized interconnects in one package, which enables designers to solve high current requirements in a small area with minimal external components.External compensation, programmable switching frequency, and current limit features allow design optimization and flexibility.

The summing current mode modulator uses lossless current sensing for current feedback and over-current protection. Voltage feedforward helps operation over a wide input voltage range.

Fairchild’s advanced BiCMOS power process, combined with low-RDS(ON) internal MOSFETs and a thermally efficient MLP package, provide the ability to dissipate high power in a small package.

Output over-voltage, under-voltage, and thermal shutdown protections help protect the device from damage during fault conditions. FAN2108 prevents prebiased output discharge during startup in point-of-load applications.

FAN2108主要特性:
Wide Input Voltage Range: 3V-24V
Wide Output Voltage Range: 0.8V to 80% VIN
8A Output Current
Programmable Frequency Operation: 200KHz to 600KHz
Over 95% Peak Efficiency
Integrated Schottky Diode on Low-side MOSFET Boosts Efficiency
Internal Bootstrap diode
Power-Good Signal
Pre-Bias Startup
Accepts Ceramic Capacitors on Output
External Compensation for Flexible Design
Input Under-Voltage Lockout
Programmable Current Limit
Under-Voltage, Over-Voltage, and Thermal Shutdown Protections
Internal Soft-Start
5x6mm, 25-Pin, 3-Pad MLP Package

应用:
Servers
Point-of-Load Regulation
High-End Computing Systems
Graphics Cards
Battery-Powered Equipment
Set-Top Boxes



图1.FAN2108方框图



图2.FAN2108典型应用电路图



图3.FAN2108应用电路图(输出电压1.8V, 500KHz)