CS2000-OTP_09 Datasheet, PDF (2/30 Pages) Cirrus Logic – Fractional-N Clock Synthesizer & Clock Multiplier

CS2000-OTP
TABLE OF CONTENTS
1. PIN DESCRIPTION ................................................................................................................................. 4
2. TYPICAL CONNECTION DIAGRAM ..................................................................................................... 5
3. CHARACTERISTICS AND SPECIFICATIONS ...................................................................................... 6
RECOMMENDED OPERATING CONDITIONS .................................................................................... 6
ABSOLUTE MAXIMUM RATINGS ........................................................................................................ 6
DC ELECTRICAL CHARACTERISTICS ................................................................................................ 6
AC ELECTRICAL CHARACTERISTICS ................................................................................................ 7
PLL PERFORMANCE PLOTS ............................................................................................................... 8
4. ARCHITECTURE OVERVIEW ............................................................................................................... 9
4.1 Delta-Sigma Fractional-N Frequency Synthesizer ........................................................................... 9
4.2 Hybrid Analog-Digital Phase Locked Loop ...................................................................................... 9
4.2.1 Fractional-N Source Selection for the Frequency Synthesizer .............................................. 10
5. APPLICATIONS ................................................................................................................................... 11
5.1 One Time Programmability ............................................................................................................ 11
5.2 Timing Reference Clock Input ........................................................................................................ 11
5.2.1 Internal Timing Reference Clock Divider ............................................................................... 11
5.2.2 Crystal Connections (XTI and XTO) ...................................................................................... 12
5.2.3 External Reference Clock (REF_CLK) .................................................................................. 12
5.3 Frequency Reference Clock Input, CLK_IN ................................................................................... 12
5.3.1 Adjusting the Minimum Loop Bandwidth for CLK_IN ............................................................ 13
5.4 Output to Input Frequency Ratio Configuration ............................................................................. 14
5.4.1 User Defined Ratio (RUD), Frequency Synthesizer Mode .................................................... 14
5.4.2 User Defined Ratio (RUD), Hybrid PLL Mode ....................................................................... 14
5.4.3 Ratio Modifier (R-Mod) .......................................................................................................... 15
5.4.4 Effective Ratio (REFF) .......................................................................................................... 15
5.4.5 Fractional-N Source Selection ............................................................................................... 15
5.4.5.1 Manual Fractional-N Source Selection for the Frequency Synthesizer ..................... 16
5.4.5.2 Automatic Fractional-N Source Selection for the Frequency Synthesizer ................. 16
5.4.6 Ratio Configuration Summary ............................................................................................... 17
5.5 PLL Clock Output ........................................................................................................................... 18
5.6 Auxiliary Output .............................................................................................................................. 18
5.7 Mode Pin Functionality ................................................................................................................... 19
5.7.1 M1 and M0 Mode Pin Functionality ....................................................................................... 19
5.7.2 M2 Mode Pin Functionality .................................................................................................... 19
5.7.2.1 M2 Configured as Output Disable .............................................................................. 19
5.7.2.2 M2 Configured as R-Mod Enable .............................................................................. 19
5.7.2.3 M2 Configured as Auto Fractional-N Source Selection Disable ................................ 20
5.7.2.4 M2 Configured as Fractional-N Source Select .......................................................... 20
5.7.2.5 M2 Configured as AuxOutSrc Override ..................................................................... 20
5.8 Clock Output Stability Considerations ............................................................................................ 20
5.8.1 Output Switching ................................................................................................................... 20
5.8.2 PLL Unlock Conditions .......................................................................................................... 21
5.9 Required Power Up Sequencing for Programmed Devices ........................................................... 21
6. PARAMETER DESCRIPTIONS ........................................................................................................... 22
6.1 Modal Configuration Sets ............................................................................................................... 22
6.1.1 R-Mod Selection (RModSel[1:0]) ........................................................................................... 22
6.1.2 Auxiliary Output Source Selection (AuxOutSrc[1:0]) ............................................................. 23
6.1.3 Lock Clock Ratio (LockClk[1:0]) ............................................................................................ 23
6.1.4 Fractional-N Source for Frequency Synthesizer (FracNSrc) ................................................. 23
6.2 Ratio 0 - 3 ...................................................................................................................................... 23
6.3 Global Configuration Parameters ................................................................................................... 24
6.3.1 AUX PLL Lock Output Configuration (AuxLockCfg) .............................................................. 24
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