逻辑电平信号-48V LED驱动器

摘要： 65V hysteretically 控制 LED 驱动程序 (MAX16822A) 有它的地面引脚连接到-48V 和输入其电源连接到系统的地面。调光，电路的逻辑级别的控制信号 （控制） 是水平转移到-48V，并应用于太暗输入，使用 80V/500mA 高电压 PNP 晶体管 （CMPT5551）。

Maxim > App Notes > Display drivers LED lighting
Keywords: LED drivers, LED dimming, -48V telecom systems, high-V PNP transistors Oct 13, 2009

APPLICATION NOTE 4619
Logic-Level Signals Dim -48V LED Driver
By: Ahmad Ayar


Abstract: A 65V hysteretically controlled LED driver (MAX16822A) has its ground pin connected to -48V and its power input
connected to the system ground. For dimming, the circuit's logic-level control signal (control) is level-shifted down to -48V and
applied to the DIM input, using an 80V/500mA high-voltage PNP transistor (CMPT5551).

This design idea appeared in the June 23, 2009 issue of Electronic Design magazine.

The main source of power in a telecommunication system is -48V. Not only the negative polarity of this source, b