Future Technology Devices International’s new USB Full Speed host IC is specifically targeted at providing Android platforms, such as tablet PCs or smartphones, with interconnectivity to end product systems through the utilization of USB technology. Running off a standard 3.3 V supply and drawing a current of just 25 mA in full operation at 48 MHz and 128 µA while in standby mode, the FT311D has the capacity to bridge the USB port to six different user selectable interface types, namely GPIO, UART, PWM, I2C master, SPI slave and SPI master. It can be utilised in conjunction with any platform that supports the Android Open Accessory mode (typically Version 3.1 of the Android operating system onwards, though some platforms may back-port Open Accessory mode to Version 2.3.4).
When the IC’s peripheral interface is configured in UART mode, the interface implements a basic asynchronous serial UART port with flow control. The FT311D’s UART can support data rates of between 300 bit/s and 6 Mbit/s, while its I2C master interface can connect to I2C slave interfaces supporting speeds of up to 125 kbit/s. The interface can also be configured to provide 4 pulse width modulation (PWM) outputs. These can be used to generate PWM signals for controlling the motors, actuators, sensors, DC/DC converters and AC/DC supplies found in such systems, as toys, lighting applications, home automation, and industrial equipment.
A development module based on the FT311D is also available. With board dimensions of 68.58 mm x 55.38 mm x 14.00 mm, this is intended for use as a hardware platform to enable easy evaluation of the IC and allow engineers to develop a broad range of Android Open Accessory compliant applications. Selection of the desired interface mode is done using a series of jumpers. This module is complemented by a 66.60 x 55.38 x 22 mm form factor GPIO shield board, which has push button keypad that acts as a user input and a set of 8 LED emitters which can be deployed to illustrate an active output. The FT311D is supplied in 32 pin QFN and LQFP package options. These ICs have an operational temperature range that covers -40 to 85 ⁰C.