The document introduces the PDIUSBD11 USB device with a serial interface. It complies with the Universal Serial Bus specification Rev. 1.1, ACPI, OnNOW, and USB power management requirements. It is also compliant with USB Human Interface Devices and Monitor Control Class. The PDIUSBD11 integrates a Serial Interface Engine, FIFO memory, and transceivers, and has automatic USB protocol handling. It has a high-speed I2C interface (up to 1 Mbit/s) and is compatible with the PDIUSBH11 software. Additionally, it features a low-frequency 12 MHz crystal oscillator, programmable output clock frequency, bus powered capability with low suspend current, and a single 3.3 V supply with 5 V tolerant I/O. It is available in 16-pin DIP and SO packages.