Power management circuit and timing controller for display device

A power management circuit connected to a power conversion circuit and a timing controller, comprising:

• a switch driving circuit configured to drive a plurality of power switches connected to the power conversion circuit;
• and
• a control circuit configured to receive a control signal from the timing controller and to change a driving condition for the switch driving circuit in response to the control signal, wherein
• the plurality of power switches has different channel widths,
• the control signal includes information on the size of a panel load,
• the control circuit is configured to select at least one power switch based on the size of the panel load and the channel width of each of one or more power switches, and to drive the selected power switch, and
• the control circuit is configured to control a bias current of an amplifier configured to supply a voltage to a common electrode of a panel in response to the control signal;
• wherein the plurality of power switches comprises a first power switch and a second power switch having a channel width wider than that of the first power switch, and
• the size of the second power switch is larger than the size of the first power switch,
• in case the size of the panel load is a first value, the control circuit is configured to drive the first power switch and is configured not to drive the second power switch,
• in case the size of the panel load is a second value, the control circuit is configured not to drive the first power switch and is configured to drive the second power switch,
• in case the size of the panel load is a third value, the control circuit is configured to drive both the first power switch and the second power switch,
• the first value is smaller than the second value, and
• the second value is smaller than the third value.