Toshiba Electronics Europe (TEE) has expanded its family of automotive audio power amplifiers with two new high-efficiency devices.
Both the TB2955HQ and TB2915HQ can operate with lower power consumption than conventional ClassAB alternatives, with the TB2955HQ offering the additional benefit of integrated I2C diagnosis functionality.
Known as 'Class KB' amplifiers, the new 49 W, four-channel linear amplifiers require just half the power consumption of Class AB amplifiers between 1 W and 3 W power out and have a standby current of only 0.01 uA. In addition to efficient, low-power amplification, as linear amplifiers the new parts have improved total harmonic distortion (THD) characteristics compared with switching amplification techniques when it comes to signal phase shifts between the front and rear speakers. The TB2955HQ I2C functionality offers additional flexibility by simplifying the design of control, diagnostic and configuration capabilities.
Both of the new amplifiers are based on Toshiba's proprietary low on-resistance (RDS(ON)), amplifier circuit structure that improves reliability, reduces output noise and offset voltage, and increases slew rate and cut-off frequency. Typical total harmonic distortion at 2 W is just 0.02 percent, while output noise voltage is typically 70 uV (between 20 Hz and 20 kHz).
Integration of an I2C interface into the TB2955HQ allows amplifier audio controls such as standby, adjustable mute delay and voltage gain to be operated via the bus as well as facilitating a number of diagnostic facilities. These cover turn-on and permanent faults in power amplifier and line driver modes and include loudspeaker open detection, output short detection and offset detection. Both amplifiers offer ESD protection to 8 kV.