Cirrus Logic CDB5374 - Manual (Page 27)

CDB5374
DS862DB1 27
input on CDB5374 can receive a lower-frequency system clock and create a synchronous higher-frequen-
cy clock using an on-board PLL.
The expected input clock frequency to the BNC clock input is set by the EXT_CLK jumper (J16). If no ex-
ternal clock is supplied to CDB5374, the PLL will free-run at the nominal output frequency.
The PLL on CDB5374 uses a voltage-controlled crystal oscillator (VCXO) to minimize jitter, and has a sin-
gle-gate phase/frequency detector and clock divider to minimize size and power.
Specification Value
Input Clock Frequency
1.024, 2.048, 4.096 MHz
8.192, 16.384, 32.768 MHz
Distributed Clock Synchronization ± 240 ns
Maximum Input Clock Jitter, RMS 1 ns
Specification Value
PLL Output Clock Frequency
32.768 MHz
Maximum Output Jitter, RMS 300 ps
Oscillator Type VCXO
Detector Architecture Phase / Frequency
Specification Value
Oscillator - Citizen 32.768 MHz VCXO
CSX750VBEL32.768MTR
Surface Mount Package Type Leadless 6-Pin, 5x7 mm
Supply Voltage, Current 3.3 V, 11 mA
Frequency Stability, Pullability ± 50 ppm, ± 90 ppm
Startup Time 4 ms
Specification Value
Phase Detector - TI LittleLogic XOR
SN74LVC1G86DBVR
Surface Mount Package Type SOT23-5
Supply Voltage, Current 3.3 V, 10
µA
Specification Value
Loop Filter Integrator - Linear Tech Op-Amp
LT1783IS5
Surface Mount Package Type SOT23-5
Supply Voltage, Current 3.3 V, 375
µA
Specification Value
Clock Divider - TI LittleLogic D-Flop
SN74LVC2G74DCTR
Surface Mount Package Type SSOP8-199
Supply Voltage, Current 3.3 V, 10
µA