An amplifier has a p-type and an n-type difference transistor pairs providing
respective outputs, and is adapted to provide the outputs of the pairs in an integrated
form. When the level of the input signal is below a predetermined level, only the
p-type difference transistor pair is activated, and when the level of the input
signal is higher than the predetermined level, the n-type difference transistor
pair is also activated. The amplifier has an expanded dynamic range with a suppressed
noise level.
