The TDA2020 is a monolithic integrated operational amplifier in a 14-lead quad in-line plastic package, intended for use as a low frequency class B power amplifier. Typically it provides 20 watts output power (d=1%) at +/-18V/4Ohms. The guaranteed output power at +/-17V/4Ohms is 15 watts (DIN norm 45500). The TDA2020 provides high output current (up to 3.5A) and has very low harmonic and cross-over distortion. Further, the device incorporates and original (and patented) short circuit protection system, comprising and arrangement for automatically limiting the dissipated power so as to keep to working point of the output transistors within their safe operating area. A conventional thermal shut-down system is also included.