Patent ID: 6538398
Filing Date: 2003-03-25
Classification: H04N

Abstract:
A cathode ray tube driver (CRT driver) circuit with cathode current detection, comprising:a video amplifier having an amplifier signal output electrode for amplifying a video input signal; a lower prestage circuit coupled to said amplifier signal output electrode for generating a video output signal in response to said video input signal at a CRT driver output electrode, said video output signal driving a coupled CRT cathode electrode, said lower prestage circuit comprising a first prestage transistor coupled in series with a second prestage transistor, said second prestage transistor having a collector output electrode for measuring current from said CRT cathode electrode; and a first voltage divider being coupled to said lower prestage circuit and a high supply voltage via an upper prestage circuit for splitting said high supply voltage between said first and second prestage transistors, said upper prestage circuit driving said voltage divider and comprising a third prestage transistor coupled in series with a fourth prestage transistor.