VITESSE
SEMICONDUCTOR CORPORATION
Advance Product Information
VSC7128
Hex Port Bypass Circuit / Dual Repeater
for 1.0625 Gb/s FC-AL Disk Arrays
Input Structures
Two input structures exists in this part; TTL and High Speed, Differential Inputs. The TTL Inputs will inter-
face with any TTL or 3.3V or 5V CMOS outputs. The High Speed, Differential Inputs are intended to be AC
Coupled per the FC-PH specification. Being AC Coupled, the High Speed, Differential Input buffers are biased
at VDD/2. Refer to Figure 2 for High Speed, Differential Input structure.
Figure 2: Input Structures
VDD +3.3 V
INPUT
Current
Limit
R
R
GND
REFCLK and TTL Inputs
A
VDD +3.3 V
INPUT
INPUT
All Resistors
3.3K
GND
High Speed Differential Input
(RX+/RX-)
B
G52177-0, Rev. 2.3
8/31/98
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741 Calle Plano, Camarillo, CA 93012 • 805/388-3700 • FAX: 805/987-5896
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