The CP2112 is a highly-integrated HID USB-to-SMBus bridge that provides a simple solution for controlling SMBus slave devices with USB using a minimum number of components and PCB space. The CP2112 includes a USB 2.0 full-speed function controller, USB transceiver, oscillator and a one-time programmable ROM in a compact 4mm x 4mm 24-pin QFN package. The on-chip one-time programmable ROM may be used to customize the USB Vendor ID, Product ID, product description string, power descriptor, device release number and device serial number as desired for OEM applications. The CP2112 uses the standard USB HID device class, which is natively supported by most operating systems. A custom driver does not need to be installed for this device. Windows applications communicate with the CP2112 through a Windows DLL, which is provided by Silicon Labs. The interface specification for the CP2112 is also available to enable development of an API for any operating system that supports HID. The CP2112 SMBus interface includes the SDA and SCL signals needed for SMBus communication and is configurable. The configuration options include the clock speed, read/write timeouts, retry counter timeout, SCL low timeouts and a 7-bit device address. The CP2112 will only ACK the 7-bit device address assigned to it but will not respond to any read/write requests. External pull-up resistors are needed for the SCL and SDA signals. The device also features a total of eight GPIO signals. The GPIO signals are controlled through USB and can be configured as Input/Output and Open-Drain/Push-Pull. Three of the GPIO signals support alternate features including a configurable clock output (48MHz to 94kHz) and a TX and RX LED toggle. Support for I/O interface voltages down to 1.8V is provided via a VIO pin. An evaluation kit for the CP2112 (Part Number: CP2112EK) is available. It includes a CP2112-based HID USB-to-SMBus evaluation board, Windows DLL and test application, USB cable and full documentation.