User's Manual

4.1 Typical Sub-Woofer Implementation
A basic AV5100 Wireless Subwoofer system block Diagram is shown in Fig. 2.
Figure 2: AV5100 Wireless Subwoofer Solution Block Diagram
A simple low cost implementation of sub-woofer design is shown in Figure 3. The sub amplifier consists of a PWM
chip plus an output stage device, but no external MCU is required as the SWA51-RX module performs the control
function using the I2C master communication port in conjunction with multiple GPIOs. The SWA51 module is
configured to accept nominal +3.3V or +5V power from the main application board. An optional reset signal can be
supplied to the SWA51-RX module and I2C or SPI slave communication can be used to control the module if
required.
Several GPIOs can be used to drive LEDs, or to connect to UI buttons. Typically 2 LEDs may be used and 1 button
for pairing purposes. Another button could be used, for example, to implement a “bass enhance” feature. Another
GPIO can be used to control the power supply to external system blocks such as the PWM IC and the output stage.
The SWA51-RX module can remain powered up during a standby or low power operating mode; however, a true
power-down mode can be implemented by configuring pin 17 (GPIO15/ADAT2/CEN) to be used as a chip-enable
pin that can be used to power down the AV5100. The SWA51 can also be completely powered down by turning off
the main 3.3V supply.
If the wireless link is lost (ex. when the sound bar is powered down), the SWA51_RX module can, after a timeout
period, power down the amplifier and output stage sections to conserve power and to help meet Energy Start
requirements.
The I2C master port from the SWA51_RX module (pins 5 and 6 on the connector) can communicate, control, and
initialize external audio ICs such as the PWM chip in this example. Other GPIOs can be used to detect fault
conditions (over temperature etc) and notify the module. The audio is routed from the SWA51-RX module to the
amplifier circuit with the I2S output port which can be configured as either a master or a slave as required. MCLK
can also be generated from the SWA51-RX module as a -12.28800MHz clock if required.