In class-G operation, the TDA7901 buck controller automatically optimizes the voltage supplied to the bridge-tied load (BTL) power stage depending on the audio-signal level. The resulting smooth, analog sound comes with near-class-D efficiency at normal listening levels. Because the power dissipation is much lower compared with a conventional class-A/B amplifier, the heatsink requirement is optimized. Integrating the buck controller in the IC contributes to reducing system size and weight. It also cuts the bill of materials, simplifies circuit design, and saves developing firmware to control the voltage rail.
The TDA7901 is suited to use in many in-vehicle information (IVI) systems, such as head units, smart cockpit systems, external amplifiers, and more. The amplifier signals full in-play diagnostics including real-time load-current monitoring through I2S or I2C interfaces, enabling ASIL-A certification of safety-related applications like warning-tone generators and acoustic vehicle alerting systems (AVAS). A digital impedance meter is also provided, ensuring systems containing the TDA7901 can meet the most demanding requirements of automotive OEMs.
With its I2S digital input and intelligent quad-BTL output, the TDA7901 delivers 4x 43W of audio power (at 4Ω load, saturated output at 14.4V). The amplifier has 80kHz bandwidth to handle high-definition audio. Its wide supply-voltage range, spanning 4.5V-18.5V, prevents disruption by start-stop engine operation and general automotive electrical transients.
The TDA7901 is due to enter production in the second half of 2022, in a Power-SO36 package. Pricing starts at $7.90 for orders of 1000 pieces.
New Automotive Gate Driver
STMicroelectronics also announced the latest L9908 integrated automotive three-phase gate driver unit (GDU) that operates in 12V, 24V, or 48V systems and has flexible input and output channels to fulfill numerous applications in conventional and hybrid/electric vehicles.
Dedicated source connections to the high-side and low-side FETs (field-effect transistors) of each half bridge let users configure the output channels independently to drive various types of loads. In addition, six separate PWM (pulse-width modulation) input pins allow independent management of the pre-driver stages for different motor-control strategies.
High accuracy is assured, with three differential current monitors for ground-referenced measurements and three channels for real-time phase-voltage monitoring. There is also a rich set of diagnostic and protection features. The L9908 is AEC-Q100 qualified and available now, in a thermally enhanced TQFP48 package.
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