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3 usb transceiver ac characteristics, 4 emc rmii ac characteristics – Rainbow Electronics W90N745CDG User Manual

Page 395

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W90N745CD/W90N745CDG

Publication Release Date: September 22, 2006

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391

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Revision

A2

7.3.3 USB Transceiver AC Characteristics

Low Speed: 75ns at C

L

= 50pF, 300ns at C

L

= 350pF

Full Speed: 4 to 20ns at C

L

= 50pF

Differential

Data Lines

10%

Rise Time

90%

Fall Time

t

F

t

R

10%

90%

C

L

C

L

Data Signal Rise and Fall Time

USB Transceiver AC Characteristics

SYMBOL DESCRIPTION

CONDITIONS MIN

MAX

UNIT

T

R

Rise Time

CL = 50 pF

4

20

ns

T

F

Fall Time

CL = 50 pF

4

20

ns

T

RFM

Rise/Fall Time Matching

90

110

%

T

DRATE

Full Speed Data Rate

Average bit rate

(12 Mb/s

± 0.25%)

11.97 12.03 Mbps

7.3.4 EMC RMII AC Characteristics

The signal timing characteristics conforms to the guidelines specified in IEEE Std. 802.3.

PHY_REFCLK

PHY_TXEN

PHY_TXD[1:0]

T

TXO

valid data

T

TXH

T

FREQ

T

RXS

T

RXH

PHY_RXERR

PHY_RXD[1:0]

PHY_CRSDV

T

DUTY

valid data