SBAS350G June   2005  – January 2021 ADS1232 , ADS1234

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 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 Typical Characteristics
  7. 7 Parameter Measurement Information
    1. 7.1 Noise Performance
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Analog Inputs (AINPX, AINNX)
      2. 8.3.2  Temperature Sensor (ADS1232 Only)
      3. 8.3.3  Low-Noise PGA
        1. 8.3.3.1 PGA Bypass Capacitor
      4. 8.3.4  Voltage Reference Inputs (REFP, REFN)
      5. 8.3.5  Clock Sources
      6. 8.3.6  Digital Filter Frequency Response
      7. 8.3.7  Settling Time
      8. 8.3.8  Data Rate
      9. 8.3.9  Data Format
      10. 8.3.10 Data Ready and Data Output (DRDY/DOUT)
      11. 8.3.11 Serial Clock Input (SCLK)
      12. 8.3.12 Data Retrieval
    4. 8.4 Device Functional Modes
      1. 8.4.1 Offset Calibration Mode
      2. 8.4.2 Standby Mode
      3. 8.4.3 Standby Mode With Offset-Calibration
      4. 8.4.4 Power-Down Mode
      5. 8.4.5 Power-Up Sequence
      6. 8.4.6 Summary of Serial Interface Waveforms
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
    1. 10.1 Power-Supply Decoupling
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Receiving Notification of Documentation Updates
    2. 12.2 Support Resources
    3. 12.3 Trademarks
    4. 12.4 Electrostatic Discharge Caution
    5. 12.5 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

8.3.1 Analog Inputs (AINPX, AINNX)

The input signal to be measured is applied to the input pins AINPx and AINNx. The positive internal input is generalized as AINP, and the negative internal input generalized as AINN. The signal is selected through the input MUX, which is controlled by pins A0 and TEMP (ADS1232) and pins A0 and A1 (ADS1234), as shown in Table 8-1 and Table 8-2.

The ADS123x accept differential input signals, but can also accept single-ended signals. When measuring single-ended signals, it is permissible to connect the negative input (AINNx) to ground only for gain = 1 or 2. When using gain = 64 or 128, connect AINNx to a level-shift voltage equal to mid-AVDD supply to comply with the input range requirement. Connect the signal to the positive input (AINPx). When the ADS123x are configured this way, only half of the converter full-scale range is used because only positive digital output codes are produced.

The analog and reference inputs are protected by ESD diodes. See Figure 8-3 for the similar connection of the ESD diodes for the analog inputs.

Table 8-1 ADS1232 Input Channel Selection With A0 and TEMP
MUX PINS SELECTED ANALOG INPUTS
TEMP A0 POSITIVE INPUT NEGATIVE INPUT
0 0 AINP1 AINN1
0 1 AINP2 AINN2
1 x Temperature sensor Temperature sensor
Table 8-2 ADS1234 Input Channel Selection With A0 and A1
MUX PINS SELECTED ANALOG INPUTS
A1 A0 POSITIVE INPUT NEGATIVE INPUT
0 0 AINP1 AINN1
0 1 AINP2 AINN2
1 0 AINP3 AINN3
1 1 AINP4 AINN3