An electronic equipment and a display driving system are provided. The display driving system includes a power management circuit and a timing circuit electrically connected to the power management circuit. The power management circuit receives an input voltage and output a working voltage according to the input voltage. The timing circuit receives the working voltage and output a predetermined command to the power management circuit. The power management circuit is further configured to select a predetermined working mode according to the predetermined command such that the power management circuit works in the predetermined working mode.