SCAS928D May   2012  – April 2019 CDCUN1208LP

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Pin Configuration Overview
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 6 Specifications
    1. 6.1  Absolute Maximum Ratings
    2. 6.2  ESD Ratings
    3. 6.3  Recommended Operating Conditions
    4. 6.4  Thermal Information
    5. 6.5  Digital Input Electrical Characteristics – OE (SCL), INSEL, ITTP, OTTP, Divide (SDA/MOSI), ERC(ADDR/CS), Mode
    6. 6.6  Universal Input (IN1, IN2) Characteristics
    7. 6.7  Clock Output Buffer Characteristics (Output Mode = LVDS)
    8. 6.8  Clock Output Buffer Characteristics (Output Mode = HCSL)
    9. 6.9  Clock Output Buffer Electrical Characteristics (Output Mode = LVCMOS)
    10. 6.10 Clock Output Buffer Electrical Characteristics (Output Mode = LVCMOS) (Continued)
    11. 6.11 Clock Output Buffer Electrical Characteristics (Output Mode = LVCMOS) (Continued)
    12. 6.12 Typical Characteristics
  7. 7 Parameter Measurement Information
    1. 7.1 Test Configurations
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagrams
    3. 8.3 Feature Description
      1. 8.3.1 Device Control Using Configuration Pins
        1. 8.3.1.1 Configuration of Output Type (OTTP)
        2. 8.3.1.2 Configuration of Edge Rate Control (ERC)
        3. 8.3.1.3 Control of Output Enable (OE)
      2. 8.3.2 Input Ports (IN1, IN2)
        1. 8.3.2.1 Configuration of the Input Type (ITTP)
        2. 8.3.2.2 Configuration of the IN2 Divider (INDIV)
      3. 8.3.3 Smart Input Multiplexer (INMUX)
        1. 8.3.3.1 Pin Configuration of the Smart Input Multiplexer (INMUX)
    4. 8.4 Device Functional Modes
      1. 8.4.1 Device Control Using the Host Interface
        1. 8.4.1.1 OE and INSEL in Host Configuration Mode
    5. 8.5 Programming
      1. 8.5.1 Host Interface Hardware Information
        1. 8.5.1.1 SPI Communication
          1. 8.5.1.1.1 CDCUN1208LP SPI Addressing
          2. 8.5.1.1.2 Writing to the CDCUN1208LP
          3. 8.5.1.1.3 Reading From the CDCUN1208LP
          4. 8.5.1.1.4 Block Write/Read Operation
        2. 8.5.1.2 I2C Communication
          1. 8.5.1.2.1 Message Transmission
            1. 8.5.1.2.1.1 Data and Address Bits
            2. 8.5.1.2.1.2 Special Symbols – Start (S) and Stop (P)
            3. 8.5.1.2.1.3 Special Symbols – Acknowledge (ACK)
            4. 8.5.1.2.1.4 Generic Message Frame
            5. 8.5.1.2.1.5 CDCUN1208LP Message Format
            6. 8.5.1.2.1.6 CDCUN1208LP Device Addressing (I2C Address)
            7. 8.5.1.2.1.7 CDCUN1208LP Device Addressing (Register Address)
          2. 8.5.1.2.2 I2C Master and Slave Handshaking
          3. 8.5.1.2.3 Block Read/Write
          4. 8.5.1.2.4 I2C Timing
    6. 8.6 Register Maps
      1. 8.6.1 Device Registers
        1. 8.6.1.1 Device Registers: Register 00-07
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 PCI Express Applications
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
        3. 9.2.1.3 Application Curves
    3. 9.3 Systems Examples
  10. 10Power Supply Recommendations
    1. 10.1 CDCUN1208LP Power Consumption
    2. 10.2 Device Power Supply Connections and Sequencing
    3. 10.3 Device Inputs (IN1, IN2)
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Receiving Notification of Documentation Updates
    2. 12.2 Community Resources
    3. 12.3 Trademarks
    4. 12.4 Electrostatic Discharge Caution
    5. 12.5 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

3 Description

The CDCUN1208LP is a 2:8 fan-out buffer featuring a wide operating supply range, two universal differential/single-ended inputs, and universal outputs (HCSL, LVDS, or LVCMOS) with edge-rate control. The clock buffer supports PCIe Gen1, Gen2 and Gen3. One of the device inputs includes a divider that provides divide values of /1, /2, /4, or /8. The CDCUN1208LP is offered in a 32-pin QFN package, reducing the solution footprint. The device is flexible and easy to use. The state of certain pins determines device configuration at power up. Alternately, the CDCUN1208LP provides a SPI/I2C port with which a host processor controls device settings. The CDCUN1208LP delivers excellent additive jitter performance, and low power consumption. The output section includes four dedicated supply pins enabling the operation of output ports from different power supply domains. This provides the ability to clock devices switching at different LVCMOS levels without the need for external logic level translation circuitry.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
CDCUN1208LP VQFN (32) 5.00 mm × 5.00 mm
  1. For all available packages, see the orderable addendum at the end of the datasheet.

Pin Configuration Overview

CDCUN1208LP pin_conf_cas928.gif