Complementary Dual Differential Inverting

We know that under a certain load impedance, the output power is proportional to the square of the output voltage, so under the same conditions , the output power
of the BTL circuit can be up to 4 times that of the OTL circuit.     BTL power amplifier circuit generally consists of three parts : main amplifier , pre-impedance conversion circuit and protection circuit . The main amplifier has input inversion, voltage excitation, push and output stages, and all stages are connected into a bridge push-pull circuit. Among them, the input inverter stage circuit uses a diamond differential input inverter circuit, and some use complementary double differential inverter circuits. Because the diamond differential circuit has special advantages, it is often used first.