VITESSE

SEMICONDUCTOR CORPORATION

Advance Product Information

VSC7146

2.5Gb/s, 20-Bit Transceiver

Page 8

© VITESSE SEMICONDUCTOR CORPORATION

741 Calle Plano, Camarillo, CA 93012 • 805/388-3700 • FAX: 805/987-5896

8/28/00

G52162-0 Rev. 2.7

Figure 6: TBC and REF Timing Waveforms

Table 5: TBC and REF Requirements

Parameters

Description

Min

Max

Units

Conditions

Necessary lag time between TBC

and REF

—2.0

ns

Measured from falling edge of REF to rising

edge of TBC.

Necessary lead time between

TBC and REF

—2.0

ns

Measured from falling edge of REF to rising

edge of TBC.

FR

Frequency Range

105

52.5

127

63.5

MHz

Range over which both transmit and receive

reference clocks on any link may be centered.

The figure on top relects TXMODE=1 and the

bottom one reflects TXMODE=0.

FO

Frequency Offset

−100

+100

ppm

Pulse Width, Low / High

4.5

2.5

ns

Min measurement refers to TXMODE=0 and

Max measurement refers to TXMODE=1.

DC

TBC and REF duty cycle

40

60

%

Measured at 1.5V.

TBC and REF rise and fall time

0.6

1.5

ns

TBC

REF

TBC

REF

REF and TBC must not have their

opposing edges coincident within

2.0ns of each other.