
Differential Clock Buffer/Driver DDR400/PC3200-Compliant
CY2SSTV857-32
.......................... Document #: 38-07557 Rev. *E Page 1 of 8
400 West Cesar Chavez, Austin, TX 78701
1+(512) 416-8500
1+(512) 416-9669
www.silabs.com
Features
Operating frequency: 60 MHz to 230 MHz
Supports 400 MHz DDR SDRAM
10 differential outputs from one differential input
Spread-Spectrum-compatible
Low jitter (cycle-to-cycle): < 75
Very low skew: < 100 ps
Power management control input
High-impedance outputs when input clock < 20 MHz
2.6V operation
Pin-compatible with CDC857-2 and -3
48-pin TSSOP and 40 QFN package
Industrial temperature of –40°C to 85°C
Conforms to JEDEC DDR specification
Description
The CY2SSTV857-32 is a high-performance, low-skew,
low-jitter zero-delay buffer designed to distribute differential
clocks in high-speed applications. The CY2SSTV857-32
generates ten differential pair clock outputs from one differ-
ential pair clock input. In addition, the CY2SSTV857-32
features differential feedback clock outpts and inputs. This
allows the CY2SSTV857-32 to be used as a zero delay buffer.
When used as a zero delay buffer in nested clock trees, the
CY2SSTV857-32 locks onto the input reference and translates
with near-zero delay to low-skew outputs.
Block Diagram
Pin Configuration
3
2
5
6
10
9
20
19
22
23
46
47
44
43
39
40
29
30
27
26
32
33
Y0
Y0#
Y1
Y1#
Y2
Y2#
Y3
Y3#
Y4
Y4#
Y5
Y5#
Y6
Y6#
Y7
Y7#
Y8
Y8#
Y9
Y9#
FBOUT
FBOUT#
Test and
Powerdown
Logic
PLL
13
14
36
35
FBIN
FBIN#
CLK
CLK#
AVDD
37
16
PD
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
VS S
Y0 #
Y0
VDDQ
Y1
Y1 #
VS S
Y2 #
Y2
VDDQ
CL K
CL K #
VDDQ
AVD D
AVS S
VS S
Y3 #
Y3
VDDQ
Y4
Y4 #
VS S
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
VS S
Y5 #
Y5
VDDQ
Y6
Y6 #
VS S
Y7 #
Y7
VDDQ
PD #
FB IN
FB IN #
VDDQ
FB O U T #
FB O U T
VS S
Y8 #
Y8
VDDQ
Y9
Y9 #
VS S
CY
2
S
STV85
7
-3
2