Despite all the talk about micropower applications, professional audio and high-end consumer applications need hundreds and thousands of watts. The highly integrated LME49810 audio power amplifier driver from National Semiconductor is a 200 V IC, designed to drive discrete high-power transistors in systems delivering up to 3000 watts. Key spec of THD+N (total harmonic distortion plus noise) is 0.0007%. To minimize distortion when the amplifier is overdriven (stuff happens!), the LME49810 includes a Baker clamp, which provides a soft-limiting transfer function, rather than hard limiting (clamping). In addition to the obvious audio applications, these drivers can be used within industrial and specialty applications such as driving piezoelectric and sonar transducers.
Maximum driver output current is 50 mA, with a 50 V/μsecond slew rate. Power supply rejection ratio (PSRR) is 100 dB, with supply rail range of ±20 to ±100 V.
Of course, where there's power, there's the need for thermal protection. The 15-lead TO-247 device includes a variety of thermal-protection schemes, including one which activates when the die temperature goes beyond 150° C.
The audio power amplifier driver is $8.50 each in 100-piece orders. The vendor provides an evaluation board design along with the data sheet and IC; click here for details.