The bridge connection of two power operational amplifiers can provide tremendous advantages in certain analog circuit designs. When utilizing this type of connection, designers can achieve output voltage swings twice that of one op amp, a doubled slew rate, and reduced second harmonic distortion. This white paper describes considerations for implementing a successful bridge connection for maximized efficiency.

Bridge Mode Operation of Power Operational Amplifiers

The bridge connection of two power op amps provides output voltage swings twice that of one op amp, and it is the only way to obtain bipolar DC coupled drive in single supply applications. Two possible situations where this is an advantage would be in applications with low supply voltages, or applications that operate amplifiers near their maximum voltage ratings in which a single amplifier would not provide sufficient drive.

There are other incidental advantages of the bridge connection. It effectively doubles the slew rate, and non-linearities become symmetrical, reducing second harmonic distortion in comparison to a single amplifier circuit.