Chapter 307

A precision wideband current probe for LCD backlight measurement

Jim Williams

Abstract

A precision wideband current probe for LCD backlight measurement is described.

Keywords

LCD backlight

current probe

cold cathode fluorescent lamp

Evaluation and optimization of cold cathode fluorescent lamp (CCFL) performance requires highly accurate AC current measurement. CCFLs, used to backlight LCD displays, typically operate at 30kHz to 70kHz with measurable harmonic content into the low MHz region.1 Accurate determination of RMS operating current is important for electrical and emissivity efficiency computations and to ensure long lamp life. Additionally, it is desirable to be able to perform current measurements in the presence ...

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