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
7.5.3.2.2 32-CLK, Single-SDO Mode (CFR.B11 = 0, CFR.B10 = 1)

The 32-CLK, single-SDO mode provides the option of using only one SDO pin (SDO_A) to read conversion results from both ADCs (ADC_A and ADC_B). SDO_B remains in 3-state and can be treated as a no connect (NC) pin.

This mode can be selected by writing CFR.B11 = 0 and CFR.B10 = 1. Figure 7-7 shows a detailed timing diagram for this mode.

GUID-EBF41BF7-73F6-4AB2-BC1A-C1DF965EF33C-low.gifFigure 7-7 32-CLK, Single-SDO Mode Timing Diagram

A CS falling edge brings the serial data bus out of 3-state and also outputs a 0 on the SDO_A pin. The device converts the sampled analog input during the conversion time (tCONV). SDO_A reads 0 during this period. After competing the conversion process, the sample-and-hold circuit goes back into sample mode. The device outputs the MSB of ADC_A on the SDO_A pin on the 16th SCLK falling edge. As shown in Table 7-10, the subsequent SCLK falling edges are used to shift out the conversion result of ADC_A followed by the conversion result of ADC_B on the SDO_A pin.

Table 7-10 Data Launch Edge
DEVICE PIN LAUNCH EDGE
CS SCLK CS
↓ ↓1 — ↓15 ↓16 — ↓27 ↓28 ↓29 ↓30 ↓31 ↓32 — ↓43 ↓44 ↓45 ↓46 ↓47 ↓48 ... ↑
ADS8353-Q1 SDO-A 0 0 — 0 D15_A — D4_A D3_A D2_A D1_A D0_A D15_B — D4_B D3_B D2_B D1_B D0_B 0 ... Hi-Z

In this mode, at least 48 SCLK falling edges must be given to validate the read or write frame. A CS rising edge ends the frame and puts the serial bus into 3-state.

See the Section 6.6 table for timing specifications specific to this serial interface mode.