SLUAAG7 October 2021 BQ25720
The following are the results tested using BQ25720EVM with a 2-cells battery.
In Figure 3-1 (left), when charge current is set to 1A and VBUS voltage increases from 5 V to 20 V, the operating modes transition from boost to buck-boost, then to buck mode. The charging current is always kept at 1A regardless of VBUS.
In Figure 3-1 (right), when charge current is set to 1A and VBUS voltage decreases from 20 V to 5 V, and operating modes transition from buck to buck-boost, then to boost mode. The charging current is always kept at 1A regardless of VBUS.
Figure 3-2 shows FRS transition waveform, which ensures that the power role swapping occurs in a timely manner to avoid experiencing momentary power loss or glitching.