CY2SSTV857-27
Differential Clock Buffer/Driver DDR333/PC2700-Compliant
Features
• Operating frequency: 60 MHz to 200 MHz
• Supports 266, 333 MHz DDR SDRAM
• 10 differential outputs from 1 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 < 10 MHz
• 2.5V operation
• Pin-compatible with CDC857-2 and -3
• 48-pin TSSOP package
• Industrial temp. of
–40°
to +85°C
• Conforms to JEDEC DDR specification
Description
The CY2SSTV857-27 is a high-performance, low-skew,
low-jitter zero-delay buffer designed to distribute differential
clocks in high-speed applications. The CY2SSTV857-27
generates ten differential pair clock outputs from one differ-
ential pair clock input. In addition, the CY2SSTV857-27
features differential feedback clock outputs and inputs. This
allows the CY2SSTV857-27 to be used as a zero-delay buffer.
When used as a zero-delay buffer in nested clock trees, the
CY2SSTV857-27 locks onto the input reference and translates
with near-zero delay to low-skew outputs.
Block Diagram
Pin Configuration
3
2
PD #
AVDD
37
16
T est and
P ow erdo w n
L o gic
5
6
10
9
20
19
22
23
46
47
44
43
Y0
Y0#
Y1
Y1#
Y2
Y2#
Y3
Y3#
Y4
Y4#
Y5
Y5#
Y6
Y6#
Y7
Y7#
Y8
Y8#
Y9
Y9#
FBO UT
FBO U T #
VSS
Y0#
Y0
VDDQ
Y1
Y1#
VSS
VSS
Y2#
Y2
VDDQ
VDDQ
C LK
C LK #
VDDQ
AVDD
AVSS
VSS
Y3#
Y3
VDDQ
Y4
Y4#
VSS
1
2
3
4
5
6
48
47
46
45
44
43
VSS
Y5#
Y5
VDDQ
Y6
Y6#
VSS
VSS
Y7#
Y7
VDDQ
PD#
F B IN
F B IN #
VDDQ
FBOUT#
FBOUT
VSS
Y8#
Y8
VDDQ
Y9
Y9#
VSS
CY2SSTV857-27
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
C LK
C LK#
F B IN
F B IN #
13
14
39
40
PLL
36
35
29
30
27
26
32
33
Rev 1.0, November 21, 2006
2200 Laurelwood Road, Santa Clara, CA 95054
Tel:(408) 855-0555
Fax:(408) 855-0550
Page 1 of 8
www.SpectraLinear.com
SPECTRALINEAR [ SPECTRALINEAR INC ]
