Hi-Speed USB Transceiver with 1.8V ULPI Interface - Multi-Frequency Reference Clock
SMSC USB3310 REV C 3 Revision 1.11 (10-31-08)
PRODUCT PREVIEW
General Description
The USB3310 is a highly integrated Hi-Speed USB 2.0 Transceiver (PHY) that supports systems
architectures based on a 13, 19.2, 24 or 26MHz reference clock. The frequency of the reference clock
is selected by configuration. It is designed to be used in both commercial and industrial temperature
applications.
The USB3310 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 USB3310 also provides
USB UART mode.
USB3310 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 USB3310 uses SMSC’s “wrapper-less” technology to implement the ULPI interface. This “wrapper-
less” 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 USB3310 is designed to operate with an external reference clock at one of four frequencies. By
using an available reference, the USB3310 saves the cost of a crystal reference.
The USB3310 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 USB3310, the VBAT and VDD33 pins should be connected together.
The USB3310 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 USB3310 can
charge its battery at more than the 500mA allowed when charging from a USB Host.
Figure 1 USB3310 Block Diagram
OTG
Carkit
Hi-Speed
USB
Transceiver
ULPI Interface
ULPI
Registers
and State
Machi ne
BIAS
Low Jitter
Integrated
PLL
Integrated
Power
Management
VBUS
ID
DP
DM
RBIAS
REFSEL[1]
ESD Protection
DATA[7:0]
REFSEL[0]
RESETB
VDD18
VDD33
VBAT
DIR
NXT
STP
CLKOUT
REFCLK
