Semiconductor integrated circuit controlling output impedance and slew rate

[0010] An object of the present invention is to provide a semiconductor integrated circuit that can perform impedance control and slew rate control independently of each other and simplify the structure of a control circuit. Another object of the present invention is to provide a semiconductor integrated circuit that makes an impedance ratio constant in any output voltages regardless of a setting value. Another object of the present invention is to provide a semiconductor integrated circuit that includes an output circuit that keeps a slew rate quantity constant as long as impedance is constant, even if combinations of MOSFETs to set impedance to a setting value change. Another object of the present invention is to provide a semiconductor integrated circuit that includes an output circuit and an input circuit that are highly integrated. Another object of the present invention is to provide an easy-to-use semiconductor integrated circuit that can increase a data transfer rate on a system. The above-mentioned and other objects and novel characteristics of the present invention will become apparent from the description of this specification and the accompanying drawings.

[0011] A typical disclosure of the invention is summarized in brief as follows. An output circuit comprising plural output MOSFETs connected in parallel is used, from among the plural output MOSFETs, the number of output MOSFETS to be turned on i

There is a problem in that this parasitic capacitance increases reflection noise in signal transfer.

Therefore, there is a problem in that, when manufacturing process and operating environment ch