BRUECKENVERSTAERKER.

摘要

A fully integratable bridge amplifier comprises two identical amplifiers (1; 5) each being provided with a first input stage (20; 40) whose inputs constitute the first non-inverting inputs (2; 6) and the first inverting inputs (3; 7) of the amplifier, a second input stage (29; 50) whose inputs constitute the second non-inverting inputs (28; 49) and the second inverting inputs (27; 48) of the amplifier, and an output stage (25; 45). The first inverting input (3; 7) of each amplifier (1; 5) is connected to the output (12) of a buffer amplifier (9) via a first resistor (R6; R9) which together with a second resistor (R5; R8) constitutes a negative feedback network between the output (4; 8) of the amplifier (1; 5) and the first inverting input (3; 7). The first non-inverting input (2; 6) is also connected to the output (12) of the buffer amplifier (9). This output (12) and consequently the first inputs (2, 3; 6, 7) of the amplifiers (1; 5) are at half the supply voltage with respect to the d.c. voltage, which is obtained by voltage division (R2, R3) of the supply voltage between the positive supply terminal (15) and ground terminal (16), while with respect to the signals this output (12) constitutes a virtual ground connection. The second non-inverting inputs (28; 49) and inverting inputs (27; 48) are at a reference voltage (Vref) with respect to the d.c. voltage. The input voltage Vi is directly applied to the second non-inverting input (28) of the first amplifier (1) and the second inverting input (48) of the second amplifier.