A Multi-Tile Power Management Integrated Circuit (MTPMIC) includes tiles including an MCU/ADC tile and a power manager tile. The power manager tile includes a set of Configurable Switching Power Supply Pulse Width Modulator (CSPSPWM) components. These components, in combination with other circuitry external to the integrated circuit, are configurable to form a selected one of a number of different switching power supply circuits. Upon power up, an internal regulator supplies power to the CSPSPWM. The CSPSPWM then controls the power supply to begin switching in a low frequency start-up mode. The CSPSPWM determines during start-up the current sensing method based on circuitry external to the integrated circuit. A supply voltage generated is then supplied via a conductor of a standardized bus to a processor in the MCU/ADC tile. The processor begins executing instructions, and as a result writes across the standardized bus to configure the various tiles of the MTPMIC.