Clock Generator - CDCEL949

CDCEL949 (正在供货)

Clock Generator

 

Special Note

Pre-programming of customer-specific settings is available. Contact your local Texas Instruments sales representative or local authorized distributor for more information.

描述

The CDCE949 and CDCEL949 are modular PLL-based low cost, high-performance, programmable clock synthesizers, multipliers and dividers. They generate up to 9 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 four independent configurable PLLs.

The CDCEx949 has separate output supply pins, VDDOUT, 1.8 V for the CDCEL949, and 2.5 V to 3.3 V for CDCE949.

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, allowing synchronization of the output frequency to an external control signal, that is, a PWM signal.

The deep M/N divider ratio allows the generation of zero-ppm audio or video, networking (WLAN, BlueTooth™, Ethernet, GPS) or Interface (USB, IEEE1394, Memory Stick) clocks from a reference input frequency, such as 27 MHz.

All PLLs support SSC (Spread-Spectrum Clocking). SSC can be Center-Spread or Down-Spread clocking. This is a common technique to reduce electro-magnetic interference (EMI).

Based on the PLL frequency and the divider settings, the internal loop-filter components are automatically adjusted to achieve high stability, and to optimize the jitter-transfer characteristics of each PLL.

The device supports non-volatile EEPROM programming for easy customization of the device to the application. It is preset to a factory-default configuration. It can be reprogrammed to a different application configuration before PCB assembly, or reprogrammed by in-system programming. All device settings are programmable through the SDA and SCL bus, a 2-wire serial interface.

Three programmable control inputs, S0, S1 and S2, can be used to control various aspects of operation including frequency selection, changing the SSC parameters to lower EMI, PLL bypass, power down, and choosing between low level or 3-state for the output-disable function.

The CDCEx949 operates in a 1.8-V environment. It operates within a temperature range of –40°C to 85°C.

特性

  • Member of Programmable Clock Generator Family
    • CDCEx913: 1 PLLs, 3 Outputs
    • CDCEx925: 2 PLLs, 5 Outputs
    • CDCEx937: 3 PLLs, 7 Outputs
    • CDCEx949: 4 PLLs, 9 Outputs
  • In-System Programmability and EEPROM
    • Serial Programmable Volatile Register
    • Nonvolatile EEPROM to Store Customer Settings
  • Flexible Input Clocking Concept
    • External Crystal: 8 to 32 MHz
    • On-Chip VCXO: Pull-Range ±150 ppm
    • Single-Ended LVCMOS Up to 160 MHz
  • Free Selectable Output Frequency Up to 230 MHz
  • Low-Noise PLL Core
    • PLL Loop Filter Components Integrated
    • Low Period Jitter (Typical 60 ps)
  • Separate Output Supply Pins
    • CDCE949: 3.3 V and 2.5 V
    • CDCEL949: 1.8 V
  • Flexible 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 Generation
  • 1.8-V Device Core Supply
  • Wide Temperature Range: –40°C to 85°C
  • Packaged in TSSOP
  • Development and Programming Kit for Easy PLL Design and Programming (TI Pro-Clock™)

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参数 与其它产品相比 扩频时钟

 
Input Level
Output Level
Special Features
Rating
Pin/Package
Operating Temperature Range (C)
Approx. Price (US$)
Divider Ratio
Function
Jitter-Peak to Peak(P-P) or Cycle to Cycle(C-C)
Number of Outputs
Output Frequency (Max) (MHz)
Output Skew (ps)
Programmability
VCC (V)
CDCEL949 CDCE913 CDCE925 CDCE937 CDCE949 CDCEL824 CDCEL913 CDCEL925 CDCEL937
Crystal
LVCMOS   
Crystal
LVCMOS   
Crystal
LVCMOS   
Crystal
LVCMOS   
Crystal
LVCMOS   
Crystal
LVCMOS   
Crystal
LVCMOS   
Crystal
LVCMOS   
Crystal
LVCMOS   
LVCMOS    LVCMOS    LVCMOS    LVCMOS    LVCMOS    LVCMOS    LVCMOS    LVCMOS    LVCMOS   
Integrated EEPROM
Multiplier/Divider
Spread Spectrum Clocking (SSC)   
Integrated EEPROM
I2C
Pin Programming
Spread Spectrum Clocking (SSC)   
Integrated EEPROM
Multiplier/Divider
Spread Spectrum Clocking (SSC)   
Integrated EEPROM
Multiplier/Divider
Spread Spectrum Clocking (SSC)   
Integrated EEPROM
Multiplier/Divider
Spread Spectrum Clocking (SSC)   
  Integrated EEPROM
Multiplier/Divider
Spread Spectrum Clocking (SSC)   
Integrated EEPROM
Multiplier/Divider
Spread Spectrum Clocking (SSC)   
Integrated EEPROM
Multiplier/Divider
Spread Spectrum Clocking (SSC)   
Catalog    Catalog    Catalog    Catalog    Catalog    Catalog    Catalog    Catalog    Catalog   
24TSSOP    14TSSOP    16TSSOP    20TSSOP    24TSSOP    16TSSOP    14TSSOP    16TSSOP    20TSSOP   
-40 to 85    -40 to 85    -40 to 85    -40 to 85    -40 to 85    -40 to 85    -40 to 85    -40 to 85    -40 to 85   
2.35 | 1ku    1.60 | 1ku    1.93 | 1ku    2.14 | 1ku    2.35 | 1ku    1.75 | 1ku    1.60 | 1ku    1.80 | 1ku    2.14 | 1ku   
Universal    Universal    Universal    Universal    Universal      Universal    Universal    Universal   
Clock Synthesizer    Clock Generator
Spread Spectrum Clock   
Clock Synthesizer    Clock Synthesizer    Clock Synthesizer    Clock Generator    Clock Synthesizer    Clock Synthesizer    Clock Synthesizer   
60 ps    60 ps    60 ps    60 ps    60 ps    60 ps    60 ps    60 ps    60 ps   
9    3    5    7    9    4    3    5    7   
230    230    230    230    230    201    230    230    230   
150    150    150    150    150    150    150    150    150   
EEPROM    EEPROM    EEPROM    EEPROM    EEPROM    EEPROM    EEPROM    EEPROM    EEPROM   
1.8    1.8    1.8    1.8    1.8    1.8    1.8    1.8    1.8   

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