DISPLAY APPARATUS POWER MANAGEMENT CONTROLLER AND METHODS OF OPERATION THEREOF

摘要

This disclosure provides systems, methods and apparatus for powering display light sources. A display can include a DC/DC converter included in a power management integrated circuit (PMIC) to serve as the light source driver. Battery current drawn by the DC/DC converter can be smoothed, in part, by introducing a capacitor in parallel with the set of light sources. A display controller can control the DC/DC converter to output a substantially constant current for substantially the entirety of a time period for displaying a set of subframes, storing enough charge on the capacitor to support the current drawn through the light sources by a digital-to-analog converter included in the PMIC. Output current level for the DC/DC converter can be determined for the time period over which the subframes are displayed. The set of subframes can include subframes of a single image frame, or of one or more image frames.

主权项

1. An apparatus comprising:
a first set of light sources including a first terminal and a second terminal; a first capacitor, coupled to the first terminal of the first set of light sources; and a power management device receiving power from a DC voltage source, including:
a first digital-to-analog converter (DAC) coupled to the first terminal of the first set of light sources, the first DAC configured to cause a plurality of current pulses to flow from the first set of light sources to illuminate the light sources for a first plurality of subframes during a first time period and for a second plurality of subframes during a second time period, anda first programmable DC/DC converter, an output of which is coupled to the second terminal of the first set of light sources and to the first capacitor,wherein the first programmable DC/DC converter is configured to:
draw a first substantially constant current from the DC voltage source and provide a first substantially constant output current over substantially the entirety of the first time period, anddraw a second substantially constant current, different from the first substantially constant current, from the DC voltage source and provide a second substantially constant output current over substantially the entirety of the second time period.