描述 The CDCE937 and CDCEL937 devices are modular PLL-based low cost, high-performance, programmable clock synthesizers, multipliers and dividers. They generate up to 7 output clocks from a single input frequency. Each output can be programmed in-system for any clock frequency up to 230?MHz, using up to three independent configurable PLLs. The CDCEx937 has separate output supply pins, VDDOUT, which is 1.8?V for CDCEL937 and to 2.5?V to 3.3?V for CDCE937. The input accepts an external crystal or LVCMOS clock signal. If an external crystal is used, an on-chip load capacitor is adequate for most applications. The value of the load capacitor is programmable from 0 to 20?pF. Additionally, an on-chip VCXO is selectable which allows synchronization of the output frequency to an external control signal, that is, PWM signal.特性Member of Programmable Clock Generator Family CDCEx913: 1-PLL, 3 Outputs CDCEx925: 2-PLL, 5 Outputs CDCEx937: 3-PLL, 7 Outputs CDCEx949: 4-PLL, 9 OutputsIn-System Programmability and EEPROM Serial Programmable Volatile Register Nonvolatile EEPROM to Store Customer SettingFlexible Input Clocking Concept External Crystal: 8 MHz to 32 MHz On-Chip VCXO: Pull Range ±150 ppm Single-Ended LVCMOS up to 160 MHzFree Selectable Output Frequency up to 230 MHzLow-Noise PLL Core PLL Loop Filter Components Integrated Low Period Jitter (Typical 60 ps)Separate Output Supply Pins CDCE937: 3.3 V and 2.5 V CDCEL937: 1.8 VFlexible Clock Driver Three User-Definable Control Inputs [S0/S1/S2], for Example, SSC Selection, Frequency Switching, Output Enable or Power Down Generates Highly Accurate Clocks for Video, Audio, USB, IEEE1394, RFID, Bluetooth?, WLAN, Ethernet?, and GPS Generates Common Clock Frequencies Used With TI-DaVinci?, OMAP?, DSPs Programmable SSC Modulation Enables 0-PPM Clock Generation1.8-V Device Power Supply Wide Temperature Range –40°C to 85°CPackaged in TSSOP Development and Programming Kit for Easy PLL Design and Programming (TI Pro-Clock?)APPLICATIONSD-TVs, STBs, IP-STBs, DVD Players, DVD Recorders, and PrintersAll other trademarks are the property of their respective owners