SLVSKW2 January   2026 ADS1278QML-SP

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Quality Conformance Inspection
    7. 5.7 Timing Requirements: SPI Format
    8. 5.8 Timing Requirements: Frame-Sync Format
    9. 5.9 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1  Sampling Aperture Matching
      2. 6.3.2  Frequency Response
        1. 6.3.2.1 High-Speed, Low-Power, And Low-Speed Modes
        2. 6.3.2.2 High-Resolution Mode
      3. 6.3.3  Phase Response
      4. 6.3.4  Settling Time
      5. 6.3.5  Data Format
      6. 6.3.6  Analog Inputs (AINP, AINN)
      7. 6.3.7  Voltage Reference Inputs (VREFP, VREFN)
      8. 6.3.8  Clock Input (CLK)
      9. 6.3.9  Mode Selection (MODE)
      10. 6.3.10 Synchronization (SYNC)
      11. 6.3.11 Power-Down ( PWDN)
      12. 6.3.12 Format[2:0]
      13. 6.3.13 Serial Interface Protocols
      14. 6.3.14 SPI Serial Interface
        1. 6.3.14.1 SCLK
        2. 6.3.14.2 DRDY/FSYNC (SPI Format)
        3. 6.3.14.3 DOUT
        4. 6.3.14.4 DIN
      15. 6.3.15 Frame-Sync Serial Interface
        1. 6.3.15.1 SCLK
        2. 6.3.15.2 DRDY/FSYNC (Frame-Sync Format)
        3. 6.3.15.3 DOUT
        4. 6.3.15.4 DIN
      16. 6.3.16 DOUT Modes
        1. 6.3.16.1 TDM Mode
        2. 6.3.16.2 TDM Mode, Fixed-Position Data
        3. 6.3.16.3 TDM Mode, Dynamic Position Data
        4. 6.3.16.4 Discrete Data Output Mode
      17. 6.3.17 Daisy-Chaining
      18. 6.3.18 Modulator Output
      19. 6.3.19 Pin Test Using Test[1:0] Inputs
      20. 6.3.20 VCOM Output
    4. 6.4 Device Functional Modes
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
      3. 7.2.3 Application Curve
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Receiving Notification of Documentation Updates
    2. 8.2 Community Resources
    3. 8.3 Trademarks
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

6.3.14.1 SCLK

The serial clock (SCLK) features a Schmitt-triggered input and shifts out data on DOUT on the falling edge. SCLK also shifts in data on the falling edge on DIN when this pin is being used for daisy-chaining. The device shifts data out on the falling edge and the user typically shifts this data in on the rising edge.

Even though the SCLK input has hysteresis, keep SCLK as clean as possible to prevent glitches from accidentally shifting the data.

SCLK can be run as fast as the CLK frequency. SCLK can be either in free-running or stop-clock operation between conversions. Note that one fCLK is required after the falling edge of DRDY until the first rising edge of SCLK. For best performance, limit fSCLK / fCLK to ratios of 1, 1/2, 1/4, 1/8, and more. When the device is configured for modulator output, SCLK becomes the modulator clock output (see the Modulator Output section).