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