TDA4APE-Q1: Whats the function of PMIC_POWER_EN1

Part Number: TDA4APE-Q1

Whats the function of the B16 pin PMIC_POWER_EN1 (Power enable output for MAIN Domain supplies) of TDA4APE6? 

In what scenarios would this pin be used? Is this pin not needed for a single-SOC system?