Patent ID: 6204730
Filing Date: 2001-03-20
Classification: H03F

Abstract:
Amplifier of the G class type, comprising at least one set of two transistor pairs (1,2; 3,4) having together four transistors (11 to 14; 19 to 22) of the same conductivity type with an input electrode, a common electrode and an output electrode, each pair (1,2; 4,3) comprising an input transistor (11,13; 19,21) and an output transistor (12,14; 20,22) in cascade, the output electrode of the input transistor (11,13; 19,21) being coupled to the input electrode of the output transistor (12,14; 20,22), whereby means (5) are provided for applying an input signal to the input electrodes of the input transistors (11,13; 19,21) of both pairs and both pairs (1,2; 3,4) are biased by two different voltage supplies (6,7; 8,9), whereby control means is provided for switching over from the voltage of one voltage supply (6; 8) to the voltage of the other voltage supply (7; 9), the transistors (11 and 12; 19 and 20) of the first pair (1; 4) of a set are connected in a Darlington circuit arrangement characterized in thatboth transistors (13 and 14; 21 and 22) of the second pair (2; 3) of said set have their common electrodes separated from each other, the common electrode of the input transistor (13 or 21) of said second pair (2 or 3) being coupled to the output electrode of the input transistor (11; 19) of said first pair (1; 4) and the common electrode of the output transistor (14; 22) of said second pair (2; 3) being coupled to the output electrode of the output transistor (12; 20) of said first pair (1; 4).