Based on the requirements of developing a new meter system
improvements has been made to the communication interface which was previously used on M-BUS slave node.The error rate is reduced by adding Schmitt trigger at the receiving end
and by changing the current modulation mode on the sending end to voltage modulation mode
the circuit becomes easier to implement.Currently this interface has been successfully applied to a slave chips
enabling 300~9600bps rates of communication.With the 0.35μm technology of 1st-silicon
the circuit is designed and simulated by Cadence Spectre and the simulation result is presented.