The invention discloses a
mutual capacitance type touch key
signal detection method. The method comprises the steps that initialization is carried out, wherein the
electric charge quantity of an A point in the initialization phase is obtained; measurement is carried out, the
voltage of the A point is obtained according to conservation of the
electric charge of the A point; whether reference
capacitance is larger than parasitic
mutual capacitance or not is judged according to the judgment result of whether the
voltage VA2 of a
capacitive coupling point A is larger than the initial
voltage of the
capacitive coupling point A or not; whether a touch
signal exists or not is judged according to the judgment result. Compared with the prior art, detection of the touch
signal is completed within one period through a reference
capacitance comparison method, the detection speed is much higher than that of a traditional relaxation oscillation method; Because of the single-period detection, a
capacitor of a touch key does not need to be charged and discharged frequently,
system power consumption is greatly saved; in addition, due to the method, a
system has very low dynamic
power consumption, working frequency can be flexibly changed, the touch key can be used under the low-power-consumption standby mode with the rigorous requirement for
power consumption, and the hardware guarantee is provided for a full-touch human-computer
interaction interface. The invention further discloses a detection circuit of the touch key signal detection method.