SLASEG6B May 2018 – June 2020 TAS3251
The VDD supply required from the system is used to power several portions of the device. It provides power to internal regulators DVDD and AVDD that are used to power digital and analog sections of the device output power stage. Connect a 1 µF ceramic capacitor to GND and ensure capacitor voltage rating is sufficient for AVDD and DVDD. See DVDD and AVDD typical voltages in Amplifier Electrical Characteristics. Proper connection, routing, and decoupling techniques are highlighted in the Layout Section and the TAS3251EVM User's Guide, which must be followed as closely as possible for proper operation and performance. Deviation from the guidance offered in the section may result in reduced performance, errant functionality, or even damage to the TAS3251 device.
Some portions of the device also require a separate power supply which is a lower voltage than the VDD supply. To simplify the power supply requirements for the system, the TAS3251 device includes integrated low-dropout (LDO) linear regulators to create these supplies. These linear regulators are internally connected to the VDD supply and their outputs are presented on AVDD and DVDD pins, providing a connection point for an external bypass capacitors. It is important to note that the linear regulators integrated in the device have only been designed to support the current requirements of the internal circuitry, and should not be used to power any additional external circuitry. Additional loading on these pins could cause the voltage to sag and increase noise injection, which negatively affects the performance and operation of the device.