Silicon Labs’ CP2130 offers a solution for bridging a Universal Serial Bus (USB) host and Serial Peripheral Interface (SPI) bus. The controller, which features driver support for Windows, OS X, and Linux, comes in a 4- by 4-mm, 24-pin QFN package. It features a USB 2.0 full-speed controller and transceiver, SPI controller (enabling communication with SPI slave devices down to 1.8 V), 348-byte programmable memory, crystal-less USB operation, and a 5-V voltage regulator rated at 100 mA. The SPI controller communicates with up to 11 SPI slave devices; 11 GPIO pins can be used as chip-selects or configured for alternate functions that would in turn eliminate external circuitry and components. Read and write throughput clock in at 6.6 and 5.8 Mbits/s, respectively. Embedded applications include USB dongles, tablets, handheld controllers and testers, blood-glucose monitors, docking stations, point-of-sales products, data-logging modules, and card readers.