PCS3P25811_15 Datasheet, PDF (1/9 Pages) ON Semiconductor – Spread Spectrum Clock Generator

PCS3P25811,
PCS3P25812,
PCS3P25814
Spread Spectrum Clock
Generator
Product Description
The PCS3P25811/12/14 devices are versatile spread spectrum
frequency modulators designed specifically for a wide range of input
clock frequencies from 4 MHz to 32 MHz.
The PCS3P25811/12/14 reduce electromagnetic interference (EMI)
at the clock source, allowing system wide reduction of EMI of down
stream clock and data dependent signals. It allows significant system
cost savings by reducing the number of circuit board layers, ferrite
beads, shielding, and other passive components that are traditionally
required to pass EMI regulations.
The PCS3P25811/12/14 can generate an EMI reduced clock from
crystal, ceramic resonator, or system clock.
The PCS3P25811/12/14 modulate the output of a single PLL in
order to “spread” the bandwidth of a synthesized clock, and more
importantly, decreases the peak amplitudes of its harmonics. This
results in significantly lower system EMI compared to the typical
narrow band signal produced by oscillators and most frequency
generators. Lowering EMI by increasing a signal’s bandwidth is called
‘spread spectrum clock generation’.
The PCS3P25811/12/14 use the most efficient and optimized
modulation profile approved by the FCC and is implemented in a
proprietary all−digital method.
The PCS3P25811/12/14 have 2 pins S0 and S1 to control the
selection of Center Spread, Down Spread and No−Spread functions.
Additionally there is a 3 level logic contol FSEL, for selecting one of
the three different frequency ranges within the operating frequency
range. Refer Input/Output Frequency Range Selection Table.
The PCS3P25811/12/14 operate from a 2.8 V to 3.6 V supply and
are available in 8 pin SOIC, and 8L 2 mm x 2 mm WDFN packages.
www.onsemi.com
8
1
SOIC−8 NB
CASE 751
1
WDFN8 2x2, 0.5P
CASE 511AQ
PIN CONFIGURATION
XIN / CLKIN 1
8 _XOUT
VSS 2
S1 ³
PCS3P25811
PCS3P25812
PCS3P25814
7 _VDD
6 _FSEL
S0 4
5 _ModOUT
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 9 of this data sheet.
Applications
The PCS3P25811/12/14 are targeted towards EMI
management in applications such as LCD Panels, MFPs,
Digital copiers, Networking, PC peripheral devices,
consumer electronics, and embedded controller systems.
Features
• Generates a 1x (PCS3P25811), 2x (PCS3P25812) and
4x(PCS3P25814) Low EMI Spread Spectrum Clock of
the Input Frequency
• Provides up to 15 dB of EMI Suppression
• Input Frequency: 4 MHz − 32 MHz
• Output Frequency: PCS3P25811: 4 MHz − 32 MHz
PCS3P25812: 8 MHz − 64 MHz
PCS3P25814: 16 MHz − 128 MHz
• Selectable Spread Options: Down Spread and Center
Spread
• Low Power Dissipation: 3.3 V: 20 mW (typ) @ 6 MHz
3.3 V: 24 mW (typ) @ 12 MHz
3.3 V: 30 mW (typ) @ 24 MHz
• Low Inherent Cycle−to−Cycle Jitter
• Supply Voltage: 2.8 V to 3.6 V
• LVCMOS Input and Output
• Functional and Pinout Compatible to Cypress
CY25811, CY25812 and CY25814
• 8−pin SOIC, and 8L 2 mm x 2 mm WDFN (TDFN)
Packages
• These Devices are Pb−Free, Halogen Free/BFR Free
and are RoHS Compliant
© Semiconductor Components Industries, LLC, 2015
1
February, 2015 − Rev. 0
Publication Order Number:
PCS3P25811/D