The ADG728 and ADG729 are CMOS analog matrix switches with a serially controlled 2-wire interface. The ADG728 is an 8-channel matrix switch， while the ADG729 is a dual 4-channel matrix switch. On resistance is closely matched between switches and very flat over the full signal range. These parts can operate equally well as either multiplexers， demultiplexers or switch arrays and the input signal range extends to the supplies. The ADG728 and ADG729 utilize a 2-wire serial interface that is compatible with the I2 C? interface standard. Both have two external address pins （A0 and A1）。 This allows the 2 LSBs of the 7-bit slave address to be set by the user. Four of each of the devices can be connected to the one bus. The ADG728 also has a RESET pin that should be tied high if not in use. Each channel is controlled by one bit of an 8-bit word. This means that these devices may be used in a number of different configurations; all， any， or none of the channels may be on at any one time. On power-up of the device， all switches will be in the OFF condition and the internal shift register will contain all zeros. All channels exhibit break-before-make switching action preventing momentary shorting when switching channels. The ADG728 and ADG729 are available in 16-lead TSSOP packages.