TAS2120 has an advanced class-H algorithm to control the integrated Boost. The class-H algorithm enables Boost supply to closely track audio signal levels and achieve high system level efficiency for extending battery life. Class-H mode is enabled using the BST_MODE[1:0] register.

The class-H algorithm buffers the input signal to enable sufficient look-ahead time required to charge the Boost output capacitor and avoid any signal clipping. The algorithm monitors the input signal level and uses system-level parameters configured in PPC3 software like Boost output voltage, Boost output capacitor, channel gain, and so forth. and computes the most optimum class-H tuning parameters. These tuning parameter registers are then calculated in the PPC3 software and configured in the corresponding CLASSH_TUNING_x[23:0] registers.

When the BST_MODE[1:0] is configured to use the device in Class-G mode or Boost always-ON mode, the max inrush current from the battery can be controlled by setting the Inrush current parameter in PPC3 software. The software generates the required coefficients in the CLASSH_TUNING_x[23:0] register based on the system level parameters configured like Boost output capacitor, Inrush current required, and so forth.