Current amplifier, particularly for a telephone line

This invention relates to amplifiers, and more particularly, to a current amplifier for a telephone line. The invention is particularly applicable for making a line amplifier part of an integrated circuit providing coupling between a MODEM and a telephone line. A telephone line current amplifier comprises a current amplifying device comprising a first, second and third amplifier connected in cascade. The current from the third amplifier forms the output current of the current amplifying device. The current from the first amplifier subtracts from the current provided by the third amplifier, and the current from the second amplifier operates as a rectifier and outputs its current onto a power supply terminal. The power supply terminal is decoupled from ground via a capacitor. Another embodiment of the telephone line current amplifier comprises only two amplifiers if less severe distortion ratios are imposed.