The AD199x is a two channel Bridge Tied Load (BTL) switching audio power amplifier with integrated modulator. The modulator accepts a 1Vrms input signal (maximum power) and generates a switching waveform to drive speakers directly. One of the two modulators can control both output stages providing twice the current for single-channel applications. A digital, microcontroller-compatible interface provides control of reset, mute and PGA gain as well as output signals for thermal and over-current error conditions. The output stage can operate from supply voltages ranging from 8V to 20V. The analog modulator and digital logic operate from a 5V supply.