Mobile Handset Transceiver Adds Tri-State Mode

The MoBL-USB TX2 transceiver for mobile handsets from Cypress Semiconductor now offers a mode that allows all I/O pins on its UTMI (USB 2.0 Transceiver Macrocell Interface) to be tri-stated. The device is optimized for Intel's newest handheld applications processor family (co-named Monahans) based on the third-generation Intel XScale architecture. The transceiver complies with the UTMI standard and has been tested in collaboration with Intel.

The new feature allows handset manufacturers to share baseband or application processor general-purpose I/O (GPIO) pins between high-speed USB and other features, such as a camera module, GPS, DVB-H, etc. The MoBL-USB TX2 device is put into a "suspend" state when USB is not in use, dropping the typical power consumption to just 8 µA and allowing the UTMI I/O pins to be tri-stated. This allows the processor to reuse and share the limited GPIO pins for other functions across two or more devices, while extending battery life with the industry's lowest standby power consumption for a USB transceiver. This effective sharing of the limited number of GPIOs is performed today with costly tri-state buffers, which also increase board space requirements. The MoBL-USB TX2 integrates this feature, thereby removing the need for external tri-state buffers.