SBASAX3A May   2025  – September 2025 ADS9326 , ADS9327

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1  Absolute Maximum Ratings
    2. 6.2  ESD Ratings
    3. 6.3  Thermal Information
    4. 6.4  Recommended Operating Conditions
    5. 6.5  Electrical Characteristics 
    6. 6.6  Electrical Characteristics: AVDD = 5V
    7. 6.7  Electrical Characteristics: AVDD = 3.3V
    8. 6.8  Timing Requirements
    9. 6.9  Switching Characteristics
    10. 6.10 Timing Diagrams
    11. 6.11 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Analog Inputs
      2. 7.3.2 Reference
        1. 7.3.2.1 Internal Reference
          1. 7.3.2.1.1 Selectable Internal Reference with 5V AVDD
        2. 7.3.2.2 External Reference
        3. 7.3.2.3 External Reference With External Reference Buffer
      3. 7.3.3 ADC Transfer Function
      4. 7.3.4 Data Interface
      5. 7.3.5 Programmable Data Averaging Filter
        1. 7.3.5.1 Simple Average
          1. 7.3.5.1.1 Simple Average with Noncontinuous CONVST
        2. 7.3.5.2 Moving Average
      6. 7.3.6 CRC on Output Data Interface
      7. 7.3.7 ADC Output Data Randomizer
      8. 7.3.8 Data Frame Width
      9. 7.3.9 Daisy-Chain Mode
        1. 7.3.9.1 Daisy-Clock Mode
    4. 7.4 Device Functional Modes
      1. 7.4.1 Reset
      2. 7.4.2 Normal Operation
      3. 7.4.3 Low-Latency Mode
      4. 7.4.4 CS-CONVST Short Mode
      5. 7.4.5 Register Read Mode
      6. 7.4.6 Initialization Sequence
    5. 7.5 Programming
      1. 7.5.1 SPI Frame Length for Register Operations
      2. 7.5.2 Register Map Lock
      3. 7.5.3 Register Write
      4. 7.5.4 Register Read
  9. 8 Register Map: ADS9327
    1. 8.1 Register Bank 0
    2. 8.2 Register Bank 1
    3. 8.3 Register Bank 2
  10. 9 Register Map: ADS9326
    1. 9.1 Register Bank 0
    2. 9.2 Register Bank 1
    3. 9.3 Register Bank 2
  11. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Analog 1VPP Sine-Cosine Encoder Interface
      2. 10.2.2 Design Requirements
      3. 10.2.3 Detailed Design Procedure
    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
    1. 13.1 Mechanical Data

7.5.3 Register Write

Register write access is enabled by following the register map unlock sequence described in the Register Map Lock section. The 16-bit registers are grouped in two register banks and are addressable with an 8-bit register address. Register bank 1 is selected for read or write operation by writing 0x02 to REG_BANK_SEL in address 0x02. Registers in bank 0 are always accessible, irrespective of the REG_BANK_SEL bits. The register addresses in bank 0 are unique and are not used in register bank 1. The 24-bit data on SDI consist of an 8-bit address and 16-bit data. The data on SDI are latched on the rising edge of SCLK. The device decodes the write command on the CS rising edge and updates the specified register with 16-bit data specified in the register write operation. Figure 7-17 shows a 24-bit SPI frame for a register write and Table 7-16 describes the steps required to write a register.

ADS9326 ADS9327 Register Write Frame Figure 7-17 Register Write Frame
Table 7-15 Register Write Sequence
FRAME NUMBER REGISTER DESCRIPTION
ADDRESS VALUE[15:0]
1 0xFE 0xB38F Unlocks the register map.
2 0xFE 0xABCD
3 0x02 0x02 Selects register bank 1. This step is only required for register bank 1.
4 REG_ADDR DATA Writes user data to the desired address. Repeat this step for the required number of register writes.
5 0xFE 0x1234 Locks the register map after register writes are completed.