Provided is a digital transmitting module included in a host device connectable to a client device. A digital transmitting module included in a host device connectable to a client device, the digital transmitting module may include: a clock generator which provides the host device with a clock whose one cycle is comprised of T1, T2, T3 and T4 connected sequentially, and a voltage encoder which receives the clock from the clock generator, receives a digital bit from the host device, generates a voltage pulse by encoding the digital bit based on the clock, and then transmits the voltage pulse to the client device.