VITESSE
SEMICONDUCTOR CORPORATION
Low Jitter
Clock Multiplier and Distributor
Advance Product Information
VSC6108/10/12
Three versions of the clock multiplier and distributor IC are available.
1. The VSC6108 has a VCO frequency of 1.6 GHz and can output clocks at 800 MHz, 400 MHz, 200 MHz,
and 100 MHz.
2. The VSC6110 has a VCO frequency of 2.0 GHz and can output clocks at 1 GHz, 500 MHz, 250 MHz, and
125 MHz.
3. The VSC6112 has a VCO frequency of 2.488 GHz and can output clocks at 1.244GHz, 622 MHz, 311MHz,
and 155MHz.
VCO multiplication and output division ratios are user-selectable. Each of the ICs can be configured for an
input frequency of 1/4, 1/8, 1/16, or 1/32 of the VCO frequency as shown in Table 1 below. The output frequen-
cies are selected as shown in Table 2 below.
Table 1: Input Frequency vs. Mode
f
IN
Mode Name
f
VCO
= f
IN
* 4
f
VCO
= f
IN
* 8
f
VCO
= f
IN
* 16
f
VCO
= f
IN
* 32
FISEL1
0
0
1
1
FISEL0
0
1
0
1
VSC6108
400 MHz
200 MHz
100 MHz
50 MHz
VSC6110
500 MHz
250 MHz
125 MHz
62.5 MHz
VSC6112
622 MHz
311 MHz
155 MHz
77.5 MHz
Table 2: Output Frequency vs. Mode
f
OUT
Mode Name
f
OUT
= f
IN
f
OUT
= f
VCO
/ 2
f
OUT
= f
VCO
/ 4
f
OUT
= f
VCO
/ 8
f
OUT
= f
VCO
/ 16
FOSEL2
0
0
0
0
1
FOSEL1
0
0
1
1
0
FOSEL0
0
1
0
1
0
VSC6108
f
IN
800 MHz
400 MHz
200 MHz
100 MHz
VSC6110
f
IN
1 GHz
500 MHz
250 MHz
125 MHz
VSC6112
f
IN
1.244GHz
622 MHz
311 MHz
155 MHz
Page 2
©
VITESSE
SEMICONDUCTOR CORPORATION
741 Calle Plano, Camarillo, CA 93012 • 805/388-3700 • FAX: 805/987-5896
G52224-0, Rev 2.1
2/15/99
VITESSE [ VITESSE SEMICONDUCTOR CORPORATION ]
