JAJSOU4C November 2011 – June 2022 TPA2015D1
PRODUCTION DATA
Speakers are non-linear loads with varying impedance (magnitude and phase) over the audio frequency. A portion of speaker load current can flow back into the boost converter output via the Class-D output H-bridge high-side device. This is dependent on the speaker's phase change over frequency, and the audio signal amplitude and frequency content.
Most portable speakers have limited phase change at the resonant frequency, typically no more than 40 or 50 degrees. To avoid excess flow-back current, use speakers with limited phase change. Otherwise, flow-back current could exceed the 10 mA rating of the boost converter voltage clamp and drive the PVOUT voltage above the absolute maximum recommended operational voltage.
Confirm proper operation by connecting the speaker to the TPA2015D1 and driving it at maximum output swing. Observe the PVOUT voltage with an oscilloscope. In the unlikely event the PVOUT voltage exceeds 6.5 V, add a 6.8 V Zener diode between PVOUT and ground to ensure the TPA2015D1 operates properly.
The amplifier has thermal overload protection and decatives if the die temperature exceeds 150°C. It automatically reactivates once die temperature returns below 150°C. Built-in output over-current protection deactivates the amplifier if the speaker load becomes short-circuited. The amplifier automatically restarts within 200 ms after the over-current event. Although the TPA2015D1 Class-D output can withstand a short between OUT+ and OUT-, do not connect either output directly to GND, PVDD, or VBAT as this could damage the device.
Do not connect OUT+ or OUT- directly to GND, PVDD, or VBAT as this could damage the Class-D output stage.