DIFFERENTIAL AMPLIFIER WITH SIGNAL-DEPENDENT OFFSET, AND MULTI-STEP DUAL-RESIDUE ANALOG-TO-DIGITAL CONVERTER INCLUDING SUCH A DIFFERENTIAL AMPLIFIER

摘要

A differential amplifier comprises two input transistors (T1, T2) and two cross-coupled transistors (T3, T4) arranged in a translinear loop, the difference voltage across the resistance (10) between the emitters of the cross-coupled transistors (T3, T4) being equal to the difference voltage across the input terminals (2, 4) plus the sum of the offset voltages across resistors (6, 8) arranged in series with the emitters of the input transistors (T1, T2). The difference current through the cross-coupled transistors (T3, T5) is replicated in output transistors (T5, T6), thereby enabling an output signal amplitude larger than the input signal amplitude to be obtained across the resistance between the emitters of the output transistors (T5, T6). The differential amplifier is suitable inter alia as an interpolating residue signal amplifier with additional underflow and overflow ranges in multi-step dual-residue analog-to-digital converters.