SBAS931B January   2019  – July 2022 ADS8353-Q1

PRODUCTION DATA  

  1. 1Features
  2. 2Applications
  3. 3Description
  4. 4Revision History
  5. 5Pin Configuration and Functions
  6. 6Specifications
    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 Timing Requirements
    7. 6.7 Switching Characteristics
    8. 6.8 Timing Diagram
    9. 6.9 Typical Characteristics
  7. 7Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Reference
      2. 7.3.2 Analog Inputs
        1. 7.3.2.1 Analog Input: Full-Scale Range Selection
        2. 7.3.2.2 Analog Input: Single-Ended and Pseudo-Differential Configurations
      3. 7.3.3 Transfer Function
    4. 7.4 Device Functional Modes
    5. 7.5 Programming
      1. 7.5.1 Serial Interface
      2. 7.5.2 Write to User-Programmable Registers
      3. 7.5.3 Data Read Operation
        1. 7.5.3.1 Reading User-Programmable Registers
        2. 7.5.3.2 Conversion Data Read
          1. 7.5.3.2.1 32-CLK, Dual-SDO Mode (CFR.B11 = 0, CFR.B10 = 0, Default)
          2. 7.5.3.2.2 32-CLK, Single-SDO Mode (CFR.B11 = 0, CFR.B10 = 1)
      4. 7.5.4 Low-Power Modes
        1. 7.5.4.1 STANDBY Mode
        2. 7.5.4.2 Software Power-Down (SPD) Mode
      5. 7.5.5 Frame Abort, Reconversion, or Short-Cycling
    6. 7.6 Register Maps
      1. 7.6.1 ADS8353-Q1 Registers
  8. 8Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Input Amplifier Selection
      2. 8.1.2 Charge Kickback Filter
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curve
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  9. 9Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Development Support
    2. 9.2 Documentation Support
      1. 9.2.1 Related Documentation
    3. 9.3 Receiving Notification of Documentation Updates
    4. 9.4 Support Resources
    5. 9.5 Trademarks
    6. 9.6 Electrostatic Discharge Caution
    7. 9.7 Glossary
      1.      Mechanical, Packaging, and Orderable Information

8.4.1 Layout Guidelines

Figure 8-6 shows a board layout example for the ADS8353-Q1 TSSOP package. Partition the printed circuit board (PCB) into analog and digital sections. Avoid crossing digital lines with the analog signal path and keep the analog input signals and the reference input signals away from noise sources. As shown in Figure 8-6, the analog input and reference signals are routed on the left side of the board and the digital connections are routed on the right side of the device.

The power sources to the device must be clean and well-bypassed. Use 10-μF, ceramic bypass capacitors in close proximity to the analog (AVDD) and digital (DVDD) power-supply pins. Avoid placing vias between the AVDD and DVDD pins and the bypass capacitors. Connect all ground pins to the ground plane using short, low impedance paths.

The REFIO-A and REFIO-B reference inputs and outputs are bypassed with 10-μF, X7R-grade, 0805-size, 16-V rated ceramic capacitors (CREF-x). Place the reference bypass capacitors as close as possible to the reference REFIO-x pins and connect the bypass capacitors using short, low-inductance connections. Avoid placing vias between the REFIO-x pins and the bypass capacitors. Small 0.1-Ω to 0.2-Ω resistors (RREF-x) are used in series with the reference bypass capacitors to improve stability.

The fly-wheel RC filters are placed immediately next to the input pins. Among ceramic surface-mount capacitors, COG (NPO) ceramic capacitors provide the best capacitance precision. The type of dielectric used in COG (NPO) ceramic capacitors provides the most stable electrical properties over voltage, frequency, and temperature changes. Figure 8-6 shows CIN-A and CIN-B filter capacitors placed across the analog input pins of the device.