Problem:
What is BTL configuration? How is BTL different than SE?

 

 
Solution:
BTL is an acronym for "bridge-tied load." A bridge-tied load configuration consists of one amplifier driving one side of a load and another amplifier (with an inverted signal from the first amplifier) driving the other side of the load. This results in 2x more voltage swing across the load than you would have in a single-ended configuration where one side of the load is tied to an amplifier and the other side to ground. Twice the voltage swing across the load equates to 4x the power to the load (P = V^2/R). So, a BTL load configuration offers 4x more power to the load than a single ended configuration from the same supply voltage. Be aware, that BTL amplifiers dissipate 4x the heat of a Single-Ended amplfier under the same supply voltage and load conditions. Refer to the TPA7x1 series parts in the applications section for more on BTL. Also note that the output DC blocking capacitors are NOT required in the BTL configuration. Since the load is tied across two amplifiers with the same DC bias and the signal across the load is the difference between the amplifier outputs, the DC bias is removed.