Spread Spectrum Clock Generator Specification Sheet

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Spread Spectrum Clock Generato

CY25818/19

Cypress Semiconductor Corporation • 198 Champion Court • San Jose, CA 95134-1709 • 408-943-2600

Document #: 38-07362 Rev. *B Revised April 11, 2006

Features

• 8- to 32-MHz input frequency range

• CY25818: 8–16 MHz

• CY25819: 16–32 MHz

• Separate modulated and unmodulated clocks

• Accepts clock, crystal, and resonator inputs

• Down spread modulation

• Power-down function

• Low-power dissipation

— CY25818 = 33 mW-typ @ 8 MHz

— CY25818 = 56 mW-typ @ 16 MHz

— CY25819 = 36 mW-typ @ 16 MHz

— CY25819 = 63 mW-typ @ 32 MHz

• Low cycle-to-cycle jitter

— SSCLK = 250 ps-typ

— REFOUT = 275 ps-typ

• Available in 8-pin (150-mil) SOIC package

Applications

• Printers and MFPs

• LCD panels and notebook PCs

• Digital copiers

•PDAs

• Automotive

• CD-ROM, VCD, and DVD

• Networking and LAN/WAN

•Scanners

•Modems

• Embedded digital systems

Benefits

• Peak electromagnetic interference (EMI) reduction by

8–16 dB

• Fast time to market

• Cost reduction

REFERENCE

DIVIDER

PD and

VCO

DIVIDER

and

MUX

INPUT

DECODER

300K

MODULATION

CONTROL

3 6

PD#

XIN/CLKIN

XOUT

VDD

VSS

SSCLK

REFCLK

VCO

COUNTER

XIN/CLKIN

Vss

SSCLK

XOUT

Vdd

PD#

REFCLK

CY25818

CY25819

8 Pin SOIC

8-pin SOIC

Block Diagram Pin Configuration

[+] Feedback

Summary of content (7 pages)

PAGE 1
CY25818/19 Spread Spectrum Clock Generator Features Applications • 8- to 32-MHz input frequency range • Printers and MFPs • CY25818: 8–16 MHz • LCD panels and notebook PCs • CY25819: 16–32 MHz • Digital copiers • Separate modulated and unmodulated clocks • PDAs • Accepts clock, crystal, and resonator inputs • Automotive • Down spread modulation • CD-ROM, VCD, and DVD • Power-down function • Networking and LAN/WAN • Low-power dissipation • Scanners — CY25818 = 33 mW-typ @ 8 MHz • Modems
PAGE 2
CY25818/19 . Pin Description Pin Name Description 1 XIN/CLK 2 Vss Power Supply Ground. 3 S0 Digital Spread% Control Pin. 3-Level input (H-M-L). Default = M. 4 SSCLK 5 REFCLK 6 PD# Power-Down Control Pin. Default = H (Vdd). 7 Vdd Positive Power Supply. 8 XOUT Clock, Crystal, or Ceramic Resonator Input Pin. Modulated Spread Spectrum Output Clock. The output frequency is referenced to input frequency. Refer to Table 2 for the amount of modulation (Spread%).
PAGE 3
CY25818/19 3-Level Digital Inputs Modulation Rate S0 digital input is designed to sense three logic levels designated as HIGH “1,” LOW “0,” and MIDDLE “M.” With this 3-Level digital input logic, the 3-Level logic is able to detect three different logic levels. Spread Spectrum Clock Generators utilize frequency modulation (FM) to distribute energy over a specific band of frequencies. The maximum frequency of the clock (fmax) and minimum frequency of the clock (fmin) determine this band of frequencies.
PAGE 4
CY25818/19 Table 5. Timing Electrical Characteristics Vdd = 3.3V ±10%, TA = 0°C to +70°C and CL = 15 pF (unless otherwise noted) Parameter Description Conditions Min. Typ. Max. Unit ICLKFR1 Input Frequency Range CY25818 8 – 16 MHz ICLKFR2 Input Frequency Range CY25819 16 – 32 MHz trise1 Clock Rise Time SSCLK and REFCLK, 0.4V to 2.4V 2.0 3.0 4.0 ns tfall1 Clock Fall Time SSCLK and REFCLK, 0.4V to 2.4V 2.0 3.0 4.
PAGE 5
CY25818/19 SSCG Profiles CY25818/19 SSCG products use a non-linear “optimized” frequency profile as shown in Figure 6 and Figure 7. The use of Cypress proprietary “optimized” frequency profile maintains flat energy distribution over the fundamental and higher order harmonics. This results in additional EMI reduction in electronic systems. Figure 7. CY25819 Spread Spectrum Profile (Frequency vs. Time)[4] Figure 6. CY25818 Spread Spectrum Profile (Frequency vs. Time)[3] Application Schematic Vdd C3 0.
PAGE 6
CY25818/19 Ordering Information Part Number Package Type Product Flow CY25818SC 8-pin SOIC Commercial, 0° to 70°C CY25818SCT 8-pin SOIC–Tape and Reel Commercial, 0° to 70°C CY25819SC 8-pin SOIC Commercial, 0° to 70°C CY25819SCT 8-pin SOIC–Tape and Reel Commercial, 0° to 70°C CY25818SXC 8-pin SOIC Commercial, 0° to 70°C CY25818SXCT 8-pin SOIC–Tape and Reel Commercial, 0° to 70°C Lead-free CY25819SXC 8-pin SOIC Commercial, 0° to 70°C CY25819SXCT 8-pin SOIC–Tape and Reel Commercial,
PAGE 7
CY25818/19 Document History Page Document Title: CY25818/19 Spread Spectrum Clock Generator Document Number: 38-07362 REV. ECN NO. Issue Date Orig. of Change Description of Change ** 112462 03/21/02 OXC New Data Sheet *A 122701 12/28/02 RBI Added power up requirements to maximum rating information. *B 448097 See ECN RGL Add Lead-free devices Document #: 38-07362 Rev.