The invention discloses a standby circuit of a handheld device and an awaken method thereof, which is characterized in that a touch IC utilizes a charge level which is produced between an operator finger and a touch pad to detect, and the finger is determined whether to touch the sensing surface by detecting the variation of the current; the touch IC transmits a sensing
signal to a
microcontroller through a first GPIO, the sensing
signal awakens the
microcontroller from a sleeping mode, and a controllable power
supply management IC is opened through a second GPIO to supply power to the device so as to complete the awakening of the entire
system; and when the finger of the operator leaves the device after the operation, a touch keystroke IC notifies that the
microcontroller that the operation of the device is completed, the microcontroller selects whether the standby is needed according to the present work situation of the device, if the standby is required, the controllable power
supply management IC is disconnected through the second GPIO, and the microcontroller enters the sleeping mode until the next awakening. Through the standby circuit, the
power consumption during the standby can be kept at the minimum level, so the transparent awaken of the
system is completed before the operation of the device, and the awakening process is free from the manual interference.