LM3485MMX/NOPB集成电路（IC）的PMIC-稳压器-DCDC开关式控制器规格书PDF中文资料

LM3485MMX/NOPB属于集成电路（IC）的PMIC-稳压器-DCDC开关式控制器。由德州仪器制造生产的LM3485MMX/NOPBDC-DC 开关控制器PMIC（电源管理集成电路）DC 到 DC 开关式控制器是用于高效率电路的稳压 IC，其配置为生成高于（突升或步升）或低于（突降或步降）输入电源的输出电源电压。其他拓扑结构可能包括：降压-升压、反激、正激、Cuk、SEPIC、全桥、半桥和推挽式。这些器件不同于需要最小电压并“烧尽”多余电压的线性稳压器。

1 Features

• Easy-to-Use Control Methodology

• No Control-Loop Compensation Required

• 4.5-V to 35-V Wide Input Range

• 1.242-V to VIN Adjustable Output Range

• High Efficiency 93%

• ±1.3% (±2% Over Temp) Internal Reference

• 100% Duty Cycle

• Maximum Operating Frequency > 1 MHz

• Current Limit Protection

2 Applications

• Set-Top Box

• DSL or Cable Modem

• PC/IA

• Auto PC

• TFT Monitor

• Battery-Powered Portable Applications

• Distributed Power Systems

• Always On Power

3 Description

The LM3485 is a high-efficiency PFET switching

regulator controller that can be used to quickly and easily develop a small, low-cost, switching buck

regulator for a wide range of applications. The

hysteretic control architecture provides for simple

design without any control-loop stability concerns using a wide variety of external components. The

PFET architecture also allows for low component

count as well as ultralow dropout, 100% duty cycle

operation. Another benefit is high efficiency operation

at light loads without an increase in output ripple.

Current limit protection is provided by measuring the

voltage across the RDS(ON) of the PFET, thus

eliminating the need for a sense resistor. The cycle-

by-cycle current limit can be adjusted with a single

resistor, ensuring safe operation over a range of

output currents.