MULTISTAGE AMPLIFIER AND INTEGRATED CIRCUIT

摘要

A power source line is separated off by a first−stage amplifier (1) which handles microsignals and other amplifiers (2,3) and separate source lines (4,8) are connected to a common power source pad (6) so that the differences in currents led in the respective amplifiers (1−3) may not cause a large potential difference between the first−stage amplifier (1) and the other amplifiers (2, 3), thereby blocking noises due to the potential differences. Signal feedback loops are differentiated by the first−stage amplifier (1) and the other amplifiers (2, 3)to avoid the unfavorableness that a large signal is fed back from the rear−stage amplifiers (2, 3) to the first−stage amplifier (1).