The recommended PCB layout for the TDA8709AT involves keeping the analog and digital grounds separate, using a star-point grounding scheme, and placing the decoupling capacitors close to the IC. A 4-layer PCB with a dedicated ground plane is also recommended.
To ensure proper power-up and initialization, the TDA8709AT requires a stable power supply, a reset signal (pin 13) that is held low for at least 10ms, and a clock signal (pin 14) that is stable before the reset signal is released.
The maximum allowed voltage on the analog input pins (pins 1-4) is VCC + 0.5V, which is typically 5.5V for a 5V supply. Exceeding this voltage can damage the device.
The TDA8709AT has a programmable gain amplifier (PGA) that can be configured using the GAIN0 and GAIN1 pins (pins 10 and 11). The gain settings can be selected by connecting these pins to VCC, GND, or leaving them open, according to the datasheet.
The VREF pin is an internal voltage reference that can be used as a reference voltage for the analog-to-digital converter (ADC). It can be connected to an external voltage reference or left open-circuit, depending on the application requirements.
