CDC5801A数据手册集成电路（IC）的时钟发生器PLL频率合成器规格书PDF

描述 Description

The CDC5801A device provides clock multiplication and division from a single-ended reference clock (REFCLK) to a differential output pair (CLKOUT/CLKOUTB). The multiply and divide terminals (MULT/DIV0:1) provide selection for frequency multiplication and division ratios, generating CLKOUT/CLOUTKB frequencies ranging from 12.5 MHz to 500 MHz with a clock input reference (REFCLK) ranging from 19 MHz to 125 MHz.

The implemented phase aligner provides the possibility to phase align (zero delay) between CLKOUT/CLKOUTB and REFCLK or any other CLK in the system by feeding the clocks that need to be aligned to the DLYCTRL and the LEADLAG terminals.

The phase aligner also allows the user to delay or advance the CLKOUT/CLKOUTB with steps of 2.6 mUI (unit interval). For every rising edge on the DLYCTRL terminal, the output clocks are delayed by 2.6-mUI step size as long as there is low on the LEADLAG terminal. Similarly, for every rising edge on the DLYCTRL terminal, the output clocks are advanced by 2.6-mUI step size as long as there is high on the LEADLAG terminal. The CDC5801A has a fail-safe power up initialization state-machine which supports proper operation under all power up conditions. As the phase between REFCLK and CLKOUT/CLKOUTB is random after power up, the application may implement a self calibration routine at power up to produce a certain phase start position, before programming a fixed delay with the clock on the DLYCTRL terminal.

Depending on the selection of the mode terminals (P0:2), the device behaves as a multiplier (by 4, 6, or 8) with the phase aligner bypassed or as a multiplier or divider with programmable delay and phase aligner functionality. Through the select terminals (P0:2) user can also bypass the phase aligner and the PLL (test mode) and output the REFCLK directly on the CLKOUT/CLKOUTB terminals. Through P0:2 terminals the outputs could be in a high impedance state. This device has another unique capability to be able to function with a wide band of voltages on the REFCLK terminal by varying the voltage on the VDDREF terminal.

The CDC5801A has a fail-safe power up initialization state-machine which supports proper operation under all power up conditions.

The CDC5801A device is characterized for operation over free-air temperatures of –40°C to 85°C.

特性 Features

• Low Jitter Clock Multiplier by x4, x6, x8. Input Frequency Range (19 MHz to 125 MHz). Supports Output Frequency From 150 MHz to 500 MHz
• Fail-Safe Power Up Initialization
• Low Jitter Clock Divider by /2, /3, /4. Input Frequency Range (50 MHz to 125 MHz). Supports Ranges of Output Frequency From 12.5 MHz to 62.5 MHz
• 2.6 mUI Programmable Bidirectional Delay Steps
• Typical 8-ps Phase Jitter (12 kHz to 20 MHz) at 500 MHz
• Typical 2.1-ps RMS Period Jitter (Entire Frequency Band) at 500 MHz
• One Single-Ended Input and One Differential Output Pair
• Output Can Drive LVPECL, LVDS, and LVTTL
• Three Power Operating Modes to Minimize Power
• Low Power Consumption (Typical 200 mW at 500 MHz)
• Packaged in a Shrink Small-Outline Package (DBQ)
• No External Components Required for PLL
• Spread Spectrum Clock Tracking Ability to Reduce EMI
• Applications: Video Graphics, Gaming Products, Datacom, Telecom
• Accepts LVCMOS, LVTTL Inputs for REFCLK Terminal
• Accepts Other Single-Ended Signal Levels at REFCLK Terminal by Programming Proper VDDREF Voltage Level (For Example, HSTL 1.5 if VDDREF = 1.6 V)
• Supports Industrial Temperature Range of -40°C to 85°C