PCS3P25811, PCS3P25812, PCS3P25814 Spread Spectrum Clock Generator www.onsemi.com Product Description The PCS3P25811/12/14 devices are versatile spread spectrum frequency modulators designed specifically for a wide range of input 8 clock frequencies from 4 MHz to 32 MHz. 1 The PCS3P25811/12/14 reduce electromagnetic interference (EMI) 1 at the clock source, allowing system wide reduction of EMI of down SOIC8 NB WDFN8 2x2, 0.5P stream clock and data dependent signals. It allows significant system CASE 751 CASE 511AQ 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. PIN CONFIGURATION The PCS3P25811/12/14 can generate an EMI reduced clock from crystal, ceramic resonator, or system clock. XIN / CLKIN 1 8 The PCS3P25811/12/14 modulate the output of a single PLL in XOUT order to spread the bandwidth of a synthesized clock, and more importantly, decreases the peak amplitudes of its harmonics. This VSS 2 7 VDD PCS3P25811 results in significantly lower system EMI compared to the typical PCS3P25812 narrow band signal produced by oscillators and most frequency PCS3P25814 3 6 S1 FSEL generators. Lowering EMI by increasing a signals bandwidth is called spread spectrum clock generation. 5 4 S0 ModOUT The PCS3P25811/12/14 use the most efficient and optimized modulation profile approved by the FCC and is implemented in a proprietary alldigital method. The PCS3P25811/12/14 have 2 pins S0 and S1 to control the ORDERING INFORMATION selection of Center Spread, Down Spread and NoSpread functions. See detailed ordering and shipping information in the package Additionally there is a 3 level logic contol FSEL, for selecting one of dimensions section on page 9 of this data sheet. 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. Applications Selectable Spread Options: Down Spread and Center The PCS3P25811/12/14 are targeted towards EMI Spread management in applications such as LCD Panels, MFPs, Low Power Dissipation: 3.3 V: 20 mW (typ) 6 MHz Digital copiers, Networking, PC peripheral devices, 3.3 V: 24 mW (typ) 12 MHz consumer electronics, and embedded controller systems. 3.3 V: 30 mW (typ) 24 MHz Features Low Inherent CycletoCycle Jitter Generates a 1x (PCS3P25811), 2x (PCS3P25812) and Supply Voltage: 2.8 V to 3.6 V 4x(PCS3P25814) Low EMI Spread Spectrum Clock of LVCMOS Input and Output the Input Frequency Functional and Pinout Compatible to Cypress Provides up to 15 dB of EMI Suppression CY25811, CY25812 and CY25814 Input Frequency: 4 MHz 32 MHz 8pin SOIC, and 8L 2 mm x 2 mm WDFN (TDFN) Output Frequency: PCS3P25811: 4 MHz 32 MHz Packages PCS3P25812: 8 MHz 64 MHz These Devices are PbFree, Halogen Free/BFR Free PCS3P25814: 16 MHz 128 MHz and are RoHS Compliant Semiconductor Components Industries, LLC, 2015 1 Publication Order Number: February, 2015 Rev. 0 PCS3P25811/DPCS3P25811, PCS3P25812, PCS3P25814 VDD FSEL S1 S0 PLL Input Decoder & Modulation Control XIN /CLKIN Crystal Frequency Oscillator Divider Phase Loop Output VCO Divider Detector Filter XOUT Feedback Divider ModOUT VSS Figure 1. Block Diagram Table 1. PIN DESCRIPTION Pin Pin Name Type Description 1 XIN / CLKIN Input Crystal connection or External Clock input. 2 VSS Power Ground to entire chip. 3 S1 Input Digital 3 level logic input (1M0) used to select Center, Down and No spread options. (Refer to Frequency Deviation Selection Table). Default = M. 4 S0 Input Digital 3 level logic input (1M0) used to select Center, Down and No spread options. (Refer to Frequency Deviation Selection Table). Default = M. 5 ModOUT Output Spread Spectrum Clock Output. 6 FSEL Input Frequency range select. Digital 3 level logic input (1M0) used to select Input Clock frequency range (Refer to Input/Output Frequency Range Selection Table). Default = M. 7 VDD Power Power supply for the entire chip (2.8 V to 3.6 V). 8 XOUT Output Crystal connection. If using an external reference, this pin must be left unconnected. Table 2. OUTPUT FREQUENCY RANGE SELECTION Part Number PCS3P25811 (1x) PCS3P25812 (2x) PCS3P25814 (4x) Input (MHz) Output (MHz) Input (MHz) Output (MHz) Input (MHz) Output (MHz) FSEL (pin 6) Modulation Rate 0 4 8 4 8 4 8 8 16 4 8 16 32 Input Frequency / 128 1 8 16 8 16 8 16 16 32 8 16 32 64 Input Frequency / 256 M 16 32 16 32 16 32 32 64 16 32 64 128 Input Frequency / 512 www.onsemi.com 2