Patent ID: 6738914
Filing Date: 2004-05-18
Classification: G06F

Abstract:
A wake-up circuit for an electronic system, comprising:a signal generator having an output terminal and adapted to generate a digital pulse signal at the output terminal, wherein the digital pulse signal has a predetermined amplitude and a predetermined duration, wherein the output terminal of the signal generator is electrically coupled to a first terminal of a pushbutton switch having a second terminal electrically coupled to a ground potential; a signal detector having a power supply terminal, a ground terminal, a first input terminal, a second input terminal and an output terminal, wherein the power supply terminal is adapted to receive power from a power supply, wherein the ground terminal is adapted to be electrically coupled to the ground potential, wherein each of the first input terminal and the second input terminal of the signal detector are adapted to receive the digital pulse signal, wherein one of the first input terminal and the second input terminal of the signal detector is electrically coupled to the first terminal of the pushbutton switch, and wherein the signal detector further comprises: a first bias circuit electrically coupled to the first input terminal of the signal detector and adapted to bias the digital pulse signal at a first predetermined direct current (DC) level; and a second bias circuit electrically coupled to the second input terminal of the signal detector and adapted to bias the digital pulse signal at a second predetermined DC level different from the first predetermined DC level, wherein a DC difference between the first predetermined DC level and the second predetermined DC level is less than the predetermined amplitude of the digital pulse signal electrically coupled to the one of the first input terminal and the second input terminal of the signal detector that is not electrically coupled to the first terminal of the pushbutton switch, wherein a first difference exists between the predetermined amplitude of a first one of the digital pulse signal received at the first terminal of the signal detector and the digital pulse signal received at the second terminal of the signal detector and the predetermined amplitude of a second different one of the digital pulse signal received at the first terminal of the signal detector and the digital pulse signal received at the second terminal of the signal detector responsive to the pushbutton switch not being actuated, wherein a second difference exists between the predetermined amplitude the first one of the digital pulse signal received at the first terminal of the signal detector and the digital pulse signal received at the second terminal of the signal detector and the predetermined amplitude of the second different one of the digital pulse signal received at the first terminal of the signal detector and the digital pulse signal received at the second terminal of the signal detector responsive to the pushbutton switch being actuated, and wherein the output terminal of the signal detector generates an output signal having a first level and a second level, different from the first level, wherein the first level is generated responsive to the first difference causing the electronic system to remain in a low power consumption mode, and wherein the second level is generated responsive to the second difference causing the electronic system to transition from the low power consumption mode to a normal power consumption mode.