LR645中文資料High Input Voltage SMPS, Start-Up/Linear Regulator數(shù)據(jù)手冊Microchip規(guī)格書

描述 Description

LR645 is a high input voltage, low output current linear regulator. It has a 3-terminal fixed output voltage version available in TO-92, TO-220 and SOT-89 packages, as well as an adjustable voltage version available in an 8-lead SOIC package. The 3-terminal version functions like any other low voltage 3-terminal regulator except it allows the use of much higher input voltages. When used in a SMPS start-up circuit, it eliminates the need for large power resistors. In this application, current is drawn from the high voltage line only during start-up. Only leakage current flows after start-up, thereby reducing the continuous power dissipation to a few milliwatts.The adjustable voltage version allows trimming of the output voltage from 8.0 to 12V. This version can also be connected to an external depletion mode MOSFET for increased output current. When used in conjunction with depletion mode MOSFET DN2540N5, an output current of up to 150mA is achieved.

特性 Features

Accepts inputs from 15 to 450V
Output currents up to 3.0mA continuous, 30mA peak
Supply current typically 50μA
Line regulation typically 0.1mV/V
Output can be trimmed from 8.0 to 12V
Output current can be increased to 150mA with external FET

簡介

LR645屬于集成電路（IC）的線性+開關(guān)穩(wěn)壓器。由Microchip制造生產(chǎn)的LR645穩(wěn)壓器 - 線性線性穩(wěn)壓器用于提供穩(wěn)定的輸出電壓，無論負(fù)載電流、輸入電壓或環(huán)境因素如何變化，這些輸出電壓通常都要保持不變。它們的工作原理要求輸入電壓維持在高于所需的輸出電壓，而且要超出某個最小量，并且在工作時會將輸入端的任何多余電壓轉(zhuǎn)換為熱量。對于大多數(shù)應(yīng)用而言，雖然這種穩(wěn)壓器的效率低于開關(guān)模式的穩(wěn)壓器，但它們通常更適合對噪聲高度敏感的應(yīng)用。