LTC1778中文资料宽工作范围、No RSENSE™ 降压型控制器数据手册ADI规格书

描述 Description

The LTC®1778 is a synchronous stepdown switching regulator controller optimized for CPU power. The controller uses a valley current control architecture to deliver very low duty cycles with excellent transient response without requiring a sense resistor. Operating frequency is selected by an external resistor and is compensated for variations in VIN.
Discontinuous mode operation provides high efficiency operation at light loads. A forced continuous control pin reduces noise and RF interference, and can assist secondary winding regulation by disabling discontinuous operation when the main output is lightly loaded.
Fault protection is provided by internal foldback current limiting, an output overvoltage comparator and optional short-circuit shutdown timer. Soft-start capability for supply sequencing is accomplished using an external timing capacitor. The regulator current limit level is user programmable. Wide supply range allows operation from 4V to 36V at the input and from 0.8V up to (0.9)VIN at the output.

特性 Features

• 无需检测电阻器
• 真正的电流模式控制
• 专为高降压比而优化
• tON(MIN) ≤ 100ns
• 极快的瞬态响应
• 可在采用陶瓷 COUT 时保持稳定
• 双路 N 沟道 MOSFET 同步驱动
• 电源良好输出电压监视器 (LTC1778)
• 可调的导通时间 (LTC1778-1)
• 宽 VIN 范围：4V 至 36V
• ±1% 0.8V 电压基准
• 可调的电流限制
• 可调的开关频率
• 可编程软启动
• 输出过压保护
• 任选的短路停机定时器
• 微功率停机模式：IQ < 30μA
• 采用 16 引脚窄体 SSOP 封装

应用 Application

• 笔记本电脑和掌上型电脑
• 分布式电源系统

简介

LTC1778属于集成电路（IC）的PMIC-稳压器-DCDC开关式控制器。由制造生产的LTC1778DC-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。