| 摘要 |
A minute impedance variation detection device (1) includes a differential amplifier (11), first and second impedances (12, 13), a sensing electrode (15) and a signal source (16). The differential amplifier (11) has first and second input ends (111, 112) and an output end (113). The first impedance (12) is connected to the first input end (111). The second impedance (13) is connected to the second input end (112). The sensing electrode (15) is connected to the second input end (112) for sensing a touch and thus receiving a touch signal. The signal source (16) is connected to the first impedance (12) and the second impedance (13) for providing an input signal inputted to the first impedance (12) and the second impedance (13). The first impedance (12) has an impedance value close to that of the second impedance (13). The differential amplifier (11) is based on the input signal and the touch signal to differentially amplify the touch signal. |
