I²C-Bus Controlled 4 x 45 W Best Efficiency Amplifier

The TDF8546 is one of a new generation of complementary quad Bridge-Tied Load (BTL) audio power amplifiers intended for automotive applications. It has a best efficiency mode with full I²C-bus controlled diagnostics, including start-up diagnostics. The TDF8546 can operate at a battery voltage as low as 6 V making this amplifier suitable for stop/start-car operation.

The new best efficiency principle uses a switch technique which reduces switching distortion. To reduce power dissipation, the new best efficiency principle uses the audio information on all four channels instead of only the front or rear signals. Dissipation is more than 65 % less than standard BTL when used for front and rear correlated audio signals. Dissipation is 35 % less than standard BTL when used for uncorrelated (delayed) audio signals between front and rear, and 17 % less for uncorrelated audio signals when the front or rear information is used.

The amplifier uses a complementary DMOS output stage in a Silicon-On-Insulator (SOI)- based BCD process. The DMOS output stage ensures a high power output signal with perfect sound quality. The SOI-based BCD process ensures a robust amplifier, where latch-up cannot occur, with good separation between the four independent channels, with every component isolated and without substrate currents.