Six Output Peak Reducing EMI Solution
W185
Cypress Semiconductor Corporation
•
3901 North First Street
•
San Jose
•
CA 95134
•
408-943-2600
July 25, 2000, rev. *A
Features
• Cypress PREMIS™ family offering
• Generates an EMI optimized clocking signal at the
output
• Selectable output frequency range
• Six 1.25%, 3.75%, or 0% down or center spread outputs
• One non-Spread output of Reference input
• Integrated loop filter components
• Operates with a 3.3V or 5V supply
• Low power CMOS design
• Available in 24-pin SSOP (Shrink Small Outline
Package)
• Outputs may be selectively disabled
Key Specifications
Supply Voltages: ........................................... VDD = 3.3V±5%
or VDD = 5V±10%
Frequency Range: ............................ 28 MHz
≤ F
in ≤ 75 MHz
Crystal Reference Range:................. 28 MHz
≤ F
in ≤ 40 MHz
Cycle to Cycle Jitter: ....................................... 300 ps (max.)
Selectable Spread Percentage: ....................1.25% or 3.75%
Output Duty Cycle: ............................... 40/60% (worst case)
Output Rise and Fall Time: .................................. 5 ns (max.)
Table 1. Modulation Width Selection
SS%
W185
Output
W185-5
Output
0Fin ≥ Fout ≥ Fin – 1.25%
Fin + 0.625% ≥ Fin≥
– 0.625%
1Fin ≥ Fout ≥ Fin – 3.75%
Fin + 1.875% ≥ Fin≥
–1.875%
Table 2. Frequency Range Selection
FS2
FS1
Frequency Range
0
0
28 MHz
≤ F
IN ≤ 38 MHz
0
1
38 MHz
≤ F
IN ≤ 48 MHz
10
46 MHz
≤ F
IN ≤ 60 MHz
11
58 MHz
≤ F
IN ≤ 75 MHz
Table 3. Output Enable
EN1
EN2
CLK0:4
CLK5
0
0
Low
Low
01
Low
Active
10
Active
Low
1
1
Active
Active
PREMIS is a trademark of Cypress Semiconductor Corporation.
Simplified Block Diagram
Pin Configuration
24
23
22
21
1
2
3
4
REFOUT
FS2
X1
X2
SSON#
RESET
FS1
VDD
5
6
7
18
19
20
VDD
NC
EN1
GND
SS%
EN2
8
9
10
15
16
17
CLK5
VDD
CLK4
GND
CLK0
VDD
13
14
GND
CLK3
11
12
CLK1
CLK2
SSOP
Spread Spectrum
W185
(EMI suppressed)
3.3V or 5.0V
Oscillator or
Spread Spectrum
W185
(EMI suppressed)
3.3V or 5.0V
XTAL
X1
X2
Reference Input
Input
Output
Output
40MHz
max.
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
