SCAS892D February   2010  – July 2025 CDCE937-Q1 , CDCEL937-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
  7. 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 Electrical Characteristics
    6. 6.6 Timing Requirements
    7. 6.7 Typical Characteristics
  8. 7 Parameter Measurement Information
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Control Terminal Setting
      2. 8.3.2 Default Device Setting
    4. 8.4 Device Functional Modes
      1. 8.4.1 SDA and SCL Serial Interface
    5. 8.5 Programming
      1. 8.5.1 Data Protocol
      2. 8.5.2 Command Code Definition
      3. 8.5.3 Generic Programming Sequence
      4. 8.5.4 Byte Write Programming Sequence
      5. 8.5.5 Byte Read Programming Sequence
      6. 8.5.6 Block Write Programming Sequence
      7. 8.5.7 Block Read Programming Sequence
      8. 8.5.8 Timing Diagram for the SDA and SCL Serial Control Interface
      9. 8.5.9 SDA and SCL Hardware Interface
  10. 9 Register Maps
    1. 9.1 SDA and SCL Configuration Registers
  11. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Spread-Spectrum Clock (SSC)
        2. 10.2.2.2 PLL Frequency Planning
        3. 10.2.2.3 Crystal Oscillator Start-Up
        4. 10.2.2.4 Frequency Adjustment With Crystal Oscillator Pulling
        5. 10.2.2.5 Unused Inputs and Outputs
        6. 10.2.2.6 Switching Between XO and VCXO Mode
      3. 10.2.3 Application Curves
    3. 10.3 Power Supply Recommendations
    4. 10.4 Layout
      1. 10.4.1 Layout Guidelines
      2. 10.4.2 Layout Example
  12. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  13. 12Revision History
  14. 13Mechanical, Packaging, and Orderable Information

3 Description

The CDCE937-Q1 and CDCEL937-Q1 devices are modular, phase-locked loop (PLL)-based programmable clock synthesizers. These devices provide flexible and programmable options, such as output clocks, input signals, and control pins, so that the user can configure the CDCEx937-Q1 to the necessary specifications.

The CDCEx937-Q1 generates up to seven output clocks from a single input frequency to enable both board space and cost savings. Additionally, with multiple outputs, the clock generator can replace multiple crystals with one clock generator. This makes the device well-suited for head unit and telematics applications in infotainment and camera systems in ADAS, as these platforms are evolving into smaller and more cost effective systems.

Furthermore, each output can be programmed in-system for any clock frequency up to 230MHz through the integrated, configurable PLL. The PLL also supports spread-spectrum clocking (SSC) with programmable down and center spread. This provides better electromagnetic interference (EMI) performance to enable customers to pass industry standards such as CISPR-25.

Customization of frequency programming and SSC are accessed using three user-defined control pins. This eliminates the additional interface requirement to control the clock. Specific power-up and power-down sequences can also be defined to the user's needs.

Package Information
PART NUMBER PACKAGE(1) PACKAGE SIZE(2)
CDCE937-Q1,
CDCEL937-Q1		 PW (TSSOP, 20) 6.50mm × 6.40mm
(1) For more information, see Section 13.
(2) The package size (length × width) is a nominal value and includes pins, where applicable.
CDCE937-Q1 CDCEL937-Q1 Simplified Block Diagram Simplified Block Diagram