摘要 |
<p>A digitizer controller includes a panel drive signal generator (10), a reference voltage generator (12), a first multiplexer (14) for selectively outputting either a panel drive signal or a reference voltage signal, a 4-channel driving portion (16) for generating a channel driving signal which is provided to each corner of a panel, a third multiplexer (26) for selectively outputting one of the finger touch signals and a stylus signal output from a stylus, a band pass filter, a rectifier (30) for rectifying the output of the band pass filter, a low pass filter (38) for detecting a substantial direct current component from the output of the rectifier (30), an analog-to-digital converter (44) for outputting the output of the low pass filter in synchronization with a panel driving control signal as a coordinates signal, and an interface (46). Therefore, the digitizer controller can be adopted to each of the stylus, finger touch and touch panel type digitizers, and in implementing a semiconductor integrated circuit, reliability is provided and power consumption is lowered.</p> |