System for compensating the offset voltage of a differential amplifier

A system for compensating the offset voltage of a differential amplifier comprising:

• an operational amplifier provided with two generators of input signals whose difference is to be amplified;
• an offset voltage compensation loop, including a comparator, an n-bit up/down counter, and a digital-analog converter means;
• the output of said comparator being connected to the input of said n-bit up/down counter, and the outputs of said counter being connected to the inputs of said digital-analog converter means;
• said digital-analog converter means including first and second n-1 bit digital-analog converters, the output of each converter being connected respectively to one of said generators of input signals so as to modulate the input signals;
• and in which the inputs of said first converter are connected to the complementary outputs of n-1 bits of said counter, and the inputs of said second converter are connected to the real outputs of said n-1 bits of said counter.