2-W STEREO AUDIO POWER AMPLIFIER WITH DC VOLUME CONTROL

The TPA0132 is a stereo Audio Power Amplifier in a 24-pin TSSOP thermally enhanced package capable of delivering 2 W of continuous RMS power per channel into 3- loads. This device minimizes the number of external components needed, which simplifies the design and frees up board space for other features. When driving 1 W into 8- speakers, the TPA0132 has less than 0.4% THD+N across its specified frequency range. Included within this device is integrated depop circuitry that virtually eliminates transients that cause noise in the speakers. Amplifier gain is controlled by means of a dc voltage input on the VOLUME terminal. There are 31 Discrete steps covering the range of +20 dB (maximum volume setting) to 40 dB (minimum volume setting) in 2 dB steps. When the VOLUME terminal exceeds 3.54 V, the device is muted. An internal input MUX allows two sets of stereo inputs to the Amplifier In notebook applications, where internal speakers are driven as BTL and the line outputs (often Headphone drive) are required to be SE, the TPA0132 automatically switches into SE mode when the SE/BTL input is activated, and this effectively reduces the gain by 6 dB. The TPA0132 consumes only 10 mA of supply current during normal operation. A miserly shutdown mode is included that reduces the supply current to less than 150 A. The PowerPAD package (PWP) delivers a level of thermal performance that was previously achievable only in TO-220-type packages. Thermal impedances of approximately 35C/W are readily realized in multilayer PCB applications. This allows the TPA0132 to operate at full power into 8- loads at ambient temperatures of 85C. By Texas Instruments