Cross-coupled folding circuit and analog-to-digital converter provided with such a folding circui

A cross coupled folding circuit comprises a reference voltage circuit to supply m reference voltages, an amplifier circuit to provide control signals, in response to an input signal and to the reference voltages and 2n-I three times cross coupled folding circuits, each of which comprising three differential transistor pairs, said differential transistors pairs being controlled by said control signals and active in a voltage range around a respective one of said reference voltages, with m=3(2''-1). In cascade with said 2n-I folding circuits, there are differential transistor pairs in n-1 successive steps 2n-1, 2n-2, 20. To obtain complete folding, switching circuits are provided, cooperating with the transistor pairs in the last 2n-2 steps of the cascade configuration, to supply the respective control signals to those transistors of the respective differential transistor pairs that provide complete folding.