*2.1. Architecture*

This paper proposes a voltage converter that offers high conversion efficiency over a wide range of loads and reduced ripple voltage. To deliver a wide load range, the operating frequency of the converter is adjusted by power managemen<sup>t</sup> software based on the task scheduling prediction. To provide reduced ripple voltage, the SC voltage converter is split into multiple units (capacitor banks) that are operated with a predefined phase difference. Figure 2a illustrates the overall structure of the proposed voltage converter which consists of an oscillator, main controller, delay elements and multiple capacitor banks. Here, each capacitor bank includes a set of Non-Overlapping Signal Drivers (NOSDs), which can minimize the switching losses at very low cost of circuit overhead.

**Figure 2.** Proposed Switched Capacitor (SC) converter: (**a**) block diagram and operation; (**b**) an example Operating State Index (OSI) table in the controller; (**c**) Voltage Conversion Ratio (VCR) table specifying control signals for each state.

The SC converter in Figure 2a has four identical capacitor banks, which operate at a phase difference of T/4. Each capacitor bank toggles between two states: state0 (charging) and state1 (delivery). Thus, one period of converter operation comprises of two clock cycles; see Figure 2a. All the capacitor banks share one controller, while each delay element defers the control signal for individual capacitor bank by T/4.
