OnSemiLV5980MC低功率损耗、高效转换降压型稳压器设计方案

OnSemi公司的LV5980MC是一款内嵌P沟道MOSFET的单通道DC-DC转换器，工作电压范围为4.5V至23V，最大输出电流为3A。可实现低功率损耗，操作电流大约为63uA。该芯片具有外部电容软启动、过流保护、欠压及过热关闭等功能特性。本文首先介绍LV5980MC、基本特性、内部框图及应用领域，并给出相应设计方案的设计原理图、元器件列表及PCB元件布局图。

LV5980MC is 1ch DC-DC converter with built-in power Pch MOSFET.The recommended operating rang is 4.5V to 23V.The maximum current is 3A.The operating current is about 63uA,and low power consumption is achieved.

LV5980MC主要特性：

·1ch SBD rectification DC-DC converter IC with built-in power Pch MOSFET
·Typical value of light load mode current is 63uA
·100mΩ High-side switch
·The oscillatory frequency is 370kHz
·When P-by-P is generated continuously,it shifts to the HICCUP opration
·External capacitor Soft-start
·4.5V to 23V Operating input voltage range
·Output voltage adjustable to 1.235V
·built-in OCP circuit with P-by-P method
·Under voltage lock-out,thermal shutdown

LV5980MC应用：

·Set top boxes
·point of load DC-DC converters
·White Goods
·DVD/Blu-ray drivers and HDD
·Office Equipment
·LCD monitors and TVs
·POS System


图1. LV5980MC内部方框图

LV5980MC方案介绍：

The LV5980MC is a fixed 370 KHz, high-output-current, Non-synchronous PWM converter that integrates a low-resistance, high-side MOSFET and a Customer Chosen, External Diode for the rectification. The LV5980MC utilizes externally compensated current mode control to provide good transient response, ease of implementation, and excellent loop stability. It regulates input voltages from 4.5 V to 23 V down to an output voltage as low as 1.235 V and is able to supply up to 3.0 A of load current. The LV5980MC includes Power Save Feature to enhance efficiency during Light Load. In low consumption mode, the device show operating current of 63 uA from VIN by shutting down unnecessary circuits.

LV5980MC方案主要参数表



LV5980MC方案原理图：



图2. LV5980MC方案原理图

LV5980MC方案材料清单：



PCB元件布局图：