ZHCS927G May 2012 – January 2018 CDCM6208
PRODUCTION DATA.
- 1 特性
- 2 應用
- 3 說明
- 4 修訂歷史記錄
- 5 Pin Configuration and Functions
-
6 Specifications
- 6.1 Absolute Maximum Ratings
- 6.2 ESD Ratings
- 6.3 Recommended Operating Conditions
- 6.4 Thermal Information, Airflow = 0 LFM
- 6.5 Thermal Information, Airflow = 150 LFM
- 6.6 Thermal Information, Airflow = 250 LFM
- 6.7 Thermal Information, Airflow = 500 LFM
- 6.8 Single-Ended Input Characteristics (SI_MODE[1:0], SDI/SDA/PIN1, SCL/PIN4, SDO/ADD0/PIN2, SCS/ADD1/PIN3, STATUS1/PIN0, RESETN/PWR, PDN, SYNCN, REF_SEL)
- 6.9 Single-Ended Input Characteristics (PRI_REF, SEC_REF)
- 6.10 Differential Input Characteristics (PRI_REF, SEC_REF)
- 6.11 Crystal Input Characteristics (SEC_REF)
- 6.12 Single-Ended Output Characteristics (STATUS1, STATUS0, SDO, SDA)
- 6.13 PLL Characteristics
- 6.14 LVCMOS Output Characteristics
- 6.15 LVPECL (High-Swing CML) Output Characteristics
- 6.16 CML Output Characteristics
- 6.17 LVDS (Low-Power CML) Output Characteristics
- 6.18 HCSL Output Characteristics
- 6.19 Output Skew and Sync to Output Propagation Delay Characteristics
- 6.20 Device Individual Block Current Consumption
- 6.21 Worst Case Current Consumption
- 6.22 Timing Requirements, I2C Timing
- 6.23 Typical Characteristics
- 7 Parameter Measurement Information
-
8 Detailed Description
- 8.1 Overview
- 8.2 Functional Block Diagram
- 8.3
Feature Description
- 8.3.1 Typical Device Jitter
- 8.3.2 Universal Input Buffer (PRI_REF, SEC_REF)
- 8.3.3 VCO Calibration
- 8.3.4 Reference Divider (R)
- 8.3.5 Input Divider (M)
- 8.3.6 Feedback Divider (N)
- 8.3.7 Prescaler Dividers (PS_A, PS_B)
- 8.3.8 Phase Frequency Detector (PFD)
- 8.3.9 Charge Pump (CP)
- 8.3.10 Fractional Output Divider Jitter Performance
- 8.3.11 Device Block-Level Description
- 8.3.12 Device Configuration Control
- 8.3.13 Configuring the RESETN Pin
- 8.3.14 Preventing False Output Frequencies in SPI/I2C Mode at Start-Up
- 8.3.15 Input MUX and Smart Input MUX
- 8.4 Device Functional Modes
- 8.5 Programming
- 8.6 Register Maps
-
9 Application and Implementation
- 9.1 Application Information
- 9.2
Typical Applications
- 9.2.1 Design Requirements
- 9.2.2
Detailed Design Procedures
- 9.2.2.1 Jitter Considerations in SERDES Systems
- 9.2.2.2 Jitter Considerations in ADC and DAC Systems
- 9.2.2.3 Configuring the PLL
- 9.2.2.4 Programmable Loop Filter
- 9.2.2.5 Loop filter Component Selection
- 9.2.2.6 Device Output Signaling
- 9.2.2.7 Integer Output Divider (IO)
- 9.2.2.8 Fractional Output Divider (FOD)
- 9.2.2.9 Output Synchronization
- 9.2.2.10 Output Mux on Y4 and Y5
- 9.2.2.11 Staggered CLK Output Power Up for Power Sequencing of a DSP
- 10Power Supply Recommendations
- 11Layout
- 12器件和文檔支持
- 13機械、封裝和可訂購信息
8.3.10 Fractional Output Divider Jitter Performance
The fractional output divider jitter performance is a function of the fraction output divider input frequency as well as actual fractional divide setting itself. To minimize the fractional output jitter, TI recommends using the least number of fractional bits and the highest input frequency possible into the divider. As observable in Figure 30, the largest jitter contribution occurs when only one fractional divider bit is selected, and especially when the bits in the middle range of the fractional divider are selected.
Figure 30. Fractional Divider Bit Selection Impact on Jitter (fFRAC = 300 MHz)
Figure 32. Fractional Divider Bit Selection Impact on TJ (Typical)
Figure 31. Fractional Divider Input Frequency Impact on Jitter (Using Divide by x.73 Example)
Figure 33. Fractional Divider Bit Selection Impact on TJ
(Maximum Jitter Across Process, Voltage and Temperature)
Tested using a LeCroy 40 Gbps RealTime scope over a time window of 200 ms. The RJ impact on TJ is estimated for a BERT 10(-12) – 1. This measurement result is overly pessimistic, as it does not bandwidth limit the high-frequencies. In a real system, the SERDES TX will BW limit the jitter through its PLL roll-off above the TX PLL bandwidth of typically bit rate divided by 10.