Abstract: A peripheral coder/decoder (codec) that has low power consumption such that the peripheral codec facilitates bus-powered peripheral devices that utilize a codec. One such peripheral device is a modem. In the case of host-based modem, a host computer provides processing capabilities while a bus-powered peripheral device contains circuitry for analog-to-digital and digital-to-analog conversions as well as circuitry for interfacing to a transmission media. The bus-powered peripheral device is coupled to the host computer by a peripheral bus. In one embodiment, the peripheral bus is a Universal Serial Bus (USB) bus and the bus-powered peripheral device is a USB device. By being bus-powered, the bus-powered peripheral device does not require its own separate power source. A method for transmitting data over the peripheral bus using the host-based modem and the bus-powered peripheral device are also disclosed.