A signal processor for reducing power consumption. The signal processor includes a signal processing circuit and a first regulator connected to the signal processing circuit. The first regulator receives an external regulated voltage from an external regulator connected to the signal processor and generates an internal regulated voltage that is in accordance with an output level of a CCD image sensor. The signal processing circuit operates with the internal regulated voltage and performs a predetermined signal processing on an image signal generated by the CCD image sensor.
A USB control system includes a first voltage controller, a control switch, a second voltage controller, and a PHY unit. The first voltage controller outputs a first internal voltage from an external voltage and a reference voltage, and the control switch regulates supplying and suspending the external voltage. The second voltage controller outputs a second internal voltage from the reference voltage and the external voltage applied through the control switch, and the PHY unit receives a request from a host using the first or second internal voltage as a voltage source. The power for certain internal blocks is suspended to reduce power consumption in the USB control system during a power-saving mode.
