A 3.3-V, low-distortion ISDN line driver with a novel quiescent current control circuit

A U-interface line driver for a single-chip ISDN (integrated services digital network) NT (network termination) in an advanced 3.3-V, 0.5-/spl mu/m CMOS technology is presented. It features a THD (total harmonic distortion) better than -68 dB for an output swing of 5 V/sub pp/ on a 67-/spl Omega/ load in a band up to 60 kHz. A novel quiescent current control circuit is implemented. The advantages of this new approach lie in the reduction of the variation of the quiescent current and the facilitation of the driver's circuits and compensation scheme.