USB3316

The USB3316 is a highly integrated Hi-Speed USB 2.0 Transceiver (PHY) that supports systems architectures based on a 19.2MHz reference clock. It is designed to be used in both commercial and industrial temperature applications.

The USB3316 meets all of the electrical requirements to be used as a Hi-Speed USB Host, Device, or an On-the-Go (OTG) device. In addition to the supporting USB signaling the USB3316 also provides USB UART mode. and USB Audio mode.

USB3316 uses the industry standard UTMI+ Low Pin Interface (ULPI) to connect the USB PHY to the Link. The industry standard ULPI interface uses a method of in-band signaling and status byte transfers between the Link and PHY, to facilitate a USB session. By using in-band signaling and status byte transfers the ULPI interface requires only 12 pins.

The USB3316 uses SMSC's "wrapper-less" technology to implement the ULPI interface. This "wrapperless" technology allows the PHY to achieve a low latency transmit and receive time. SMSC's low latency transceiver allows an existing UTMI Link to be reused by adding a UTMI to ULPI bridge. By adding a bridge to the ASIC the existing and proven UTMI Link IP can be reused.

The USB3316 is designed to run with a 19.2MHz reference clock. By using a reference clock from the Link the USB3316 is able to remove the cost of a crystal reference from the design.

The USB3316 includes a integrated 3.3V LDO regulator to generate its own supply from power applied  at the VBAT pin. The voltage on the VBAT pin can range from 3.1 to 5.5V. The regulator dropout  voltage is less than 100mV which allows the PHY to continue USB signaling when the voltage on VBAT drops to 3.1V. The USB transceiver will continue to operate at lower voltages, although some parameters may be outside the limits of the USB specifications. If the user would like to provide a 3.3Vsupply to the USB3316, the VBAT and VDD 3.3 pins should be connected together.

The USB3316 also includes integrated pull-up resistors that can be used for detecting the attachment of a USB Charger. By sensing the attachment to a USB Charger, a product using the USB3316 can charge its battery at more than the 500mA allowed when charging from a USB Host.

The USB3316 also includes support for USB audio modes. The user can program the PHY into UART or audio mode while in synchronous mode.

In USB UART mode, the USB3316 DP and DM pins are redefined to enable pass-through of asynchronous serial data. The USB3316 can only enter UART mode when the user programs the part into this mode.

In USB audio mode, the DP pin is shorted to the SPKR_R/M pin with a switch. The DM pin is shorted to the SPKR_L pin. These switches are on when the RESETB pin of the USB3316 is asserted. Audio signals may be transferred over the USB cable. In addition to audio signals, the switches can also be used to connect Full Speed USB from another PHY onto the USB cable.