Base coupled logic circuit - has two amplifier stages with different gains to prevent first stage transistor saturation

摘要

The logic circuit has a differential amplifier, consisting of two amplifier stages, each with a upm-transistor. The gain of the first amplifier stage is chosen to be lower than that of the second one, in order to prevent without exception the saturation of the first amplifier stage transistor. The first amplifier stage transistor is used with a lower current amplification than that in the second stage. The differential amplifying rate depends both on the operational voltage and on the required output voltages, as well as on the base resistor value which affects the base voltage variations. The circuit is suitable for application with high pulse frequencies.