SYNCHRONIZING A SWITCHED POWER SUPPLY

摘要

Embodiments described herein synchronize a switching frequency of switched power supplies with timing events associated with updating a display screen or performing touch sensing. For example, a touch event may be the time needed for a touch controller to scan a plurality of sensing electrodes. Because noise is introduced each time switched power supplies switch between different stages, the touch controller may instruct a power management controller to switch between the stages (i.e., adjust the switching frequency) at the same time during each touch event. Even though the switched power supplies are permitted to introduce noise into the touch system, the noise happens at the same time during each touch event. Accordingly, the effect of the noise is the same for each touch event and is cancelled out. A similar process may be used for synchronizing the switching frequency to display events.

主权项

1. An electronic device comprising:
a power management controller configured to provide power to both a display controller configured to update a display screen and a touch controller configured to detect interaction between an input object and a sensing region, wherein the power management controller is configured to communicate with the display and touch controllers to adjust a switching frequency of a power supply to be synchronous with display timing and touch timing.