Hi-Speed USB Transceiver with 1.8V ULPI Interface - Multi-Frequency Reference Clock

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.

REFSEL[1] REFSEL[0]

REFCLK

VBUS ID

DP

DM

ESD Protection

 

LowJitter

 

 

 

Integrated

BIAS

RBIAS

OTG

PLL

 

 

 

 

 

 

 

Integrated

RESETB

 

 

Power

VBAT

 

 

VDD33

Hi-Speed

 

Management

 

VDD18

USB

ULPI

 

 

Transceiver

Registers

 

STP

 

and State

 

 

ULPI Interface

NXT

 

Machine

 

DIR

Carkit

 

 

CLKOUT

 

 

 

 

 

DATA[7:0]

 

Figure 1 USB3310 Block Diagram

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.

SMSC USB3310 REV C

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Revision 1.11 (10-31-08)