OnSemiLV5980MC低功率損耗、高效轉換降壓型穩壓器設計方案

OnSemi公司的LV5980MC是一款內嵌P溝道MOSFET的單通道DC-DC轉換器，工作電壓范圍為4.5V至23V，最大輸出電流為3A。可實現低功率損耗，操作電流大約為63uA。該芯片具有外部電容軟啟動、過流保護、欠壓及過熱關閉等功能特性。本文首先介紹LV5980MC、基本特性、內部框圖及應用領域，并給出相應設計方案的設計原理圖、元器件列表及PCB元件布局圖。

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應用：

·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


圖1. LV5980MC內部方框圖

LV5980MC方案介紹：

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方案主要參數表



LV5980MC方案原理圖：



圖2. LV5980MC方案原理圖

LV5980MC方案材料清單：



PCB元件布局圖：