USB3450-FZG SMSC [SMSC Corporation], USB3450-FZG Datasheet - Page 24

• Manufacturer Part Number: USB3450-FZG
• Description: HI-SPEED USB HOST OR DEVICE PHY WITH UTMI+INTERFACE
• Manufacturer: SMSC [SMSC Corporation]

Revision 0.1 (05-11-05)
6.4
6.4.1
6.4.2
The receivers connect directly to the USB cable. The block contains a separate differential receiver
for HS and FS mode. Depending on the mode, the selected receiver provides the serial data stream
through the mulitplexer to the RX Logic block. The FS mode section of the FS/HS RX block also
consists of a single-ended receiver on each of the data lines to determine the correct FS LINESTATE.
For HS mode support, the FS/HS RX block contains a squelch circuit to insure that noise is never
interpreted as data.
The SMSC Hi-Speed Transceiver consists of four blocks in the lower left corner of
page
High Speed and Full Speed Transceivers
The USB3450 transceiver meets all requirements in the Hi-Speed specification.
The receivers connect directly to the USB cable. This block contains a separate differential receiver
for HS and FS mode. Depending on the mode, the selected receiver provides the serial data stream
through the multiplexer to the RX Logic block. The FS mode section of the FS/HS RX block also
consists of a single-ended receiver on each of the data lines to determine the correct FS linestate. For
HS mode support, the FS/HS RX block contains a squelch circuit to insure that noise is never
interpreted as data.
The transmitters connect directly to the USB cable. The block contains a separate differential FS and
HS transmitter which receive encoded, bit stuffed, serialized data from the TX Logic block and transmit
it on the USB cable.
Termination Resistors
The USB3450 transceiver fully integrates all of the USB termination resistors. The USB3450 includes
two 1.5kΩ pull-up resistors on DP and DM and a 15kΩ pull-down resistor on both DP and DM. In
addition the 45Ω high speed termination resistors are also integrated. These integrated resistors
require no tuning or trimming by the Link. The state of the resistors is determined by the operating
mode of the PHY. The possible valid resistor combinations are shown in
guaranteed in the configurations given in
■
Hi-Speed Transceiver
RPU_DP_EN activates the 1.5kΩ DP pull-up resistor
9. These four blocks are labeled HS XCVR, FS/LS XCVR, Resistors, and Bias Gen.
Figure 6.7 Receive Timing for Data Packet (with CRC-16)
DATASHEET
Table 6.1, "DP/DM termination vs. Signaling
24
Hi-Speed USB Host or Device PHY With UTMI+ Interface
Table
6.1. Operation is
Mode".
SMSC USB3450
Figure 2.1 on
Datasheet