Hi-Speed USB Transceiver with 1.8V ULPI Interface - 13MHz Reference Clock

Revision 1.3 (11-02-07)

4

SMSC USB3319

PRODUCT PREVIEW

The USB3319 is designed to run with a 13MHz reference clock. By using a reference clock from the

Link the USB3319 is able to remove the cost of a crystal reference from the design.

The USB3319 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 3.3V

supply to the USB3319, the VBAT and VDD3.3 pins should be connected together.

The USB3319 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 USB3319 can

charge its battery at more than the 500mA allowed when charging from a USB Host.

The USB3319 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 USB3319 DP and DM pins are redefined to enable pass-through of

asynchronous serial data. The USB3319 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 USB3319 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.