SBAS473E May   2009  – January 2018 ADS1013 , ADS1014 , ADS1015

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Block Diagrams
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Timing Requirements: I2C
    7. 7.7 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagrams
    3. 8.3 Feature Description
      1. 8.3.1 Multiplexer
      2. 8.3.2 Analog Inputs
      3. 8.3.3 Full-Scale Range (FSR) and LSB Size
      4. 8.3.4 Voltage Reference
      5. 8.3.5 Oscillator
      6. 8.3.6 Output Data Rate and Conversion Time
      7. 8.3.7 Digital Comparator (ADS1014 and ADS1015 Only)
      8. 8.3.8 Conversion Ready Pin (ADS1014 and ADS1015 Only)
      9. 8.3.9 SMbus Alert Response
    4. 8.4 Device Functional Modes
      1. 8.4.1 Reset and Power-Up
      2. 8.4.2 Operating Modes
        1. 8.4.2.1 Single-Shot Mode
        2. 8.4.2.2 Continuous-Conversion Mode
      3. 8.4.3 Duty Cycling For Low Power
    5. 8.5 Programming
      1. 8.5.1 I2C Interface
        1. 8.5.1.1 I2C Address Selection
        2. 8.5.1.2 I2C General Call
        3. 8.5.1.3 I2C Speed Modes
      2. 8.5.2 Slave Mode Operations
        1. 8.5.2.1 Receive Mode
        2. 8.5.2.2 Transmit Mode
      3. 8.5.3 Writing To and Reading From the Registers
      4. 8.5.4 Data Format
    6. 8.6 Register Map
      1. 8.6.1 Address Pointer Register (address = N/A) [reset = N/A]
        1. Table 4. Address Pointer Register Field Descriptions
      2. 8.6.2 Conversion Register (P[1:0] = 0h) [reset = 0000h]
        1. Table 5. Conversion Register Field Descriptions
      3. 8.6.3 Config Register (P[1:0] = 1h) [reset = 8583h]
        1. Table 6. Config Register Field Descriptions
      4. 8.6.4 Lo_thresh (P[1:0] = 2h) [reset = 8000h] and Hi_thresh (P[1:0] = 3h) [reset = 7FFFh] Registers
        1. Table 7. Lo_thresh and Hi_thresh Register Field Descriptions
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Basic Connections
      2. 9.1.2 Single-Ended Inputs
      3. 9.1.3 Input Protection
      4. 9.1.4 Unused Inputs and Outputs
      5. 9.1.5 Analog Input Filtering
      6. 9.1.6 Connecting Multiple Devices
      7. 9.1.7 Quickstart Guide
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Shunt Resistor Considerations
        2. 9.2.2.2 Operational Amplifier Considerations
        3. 9.2.2.3 ADC Input Common-Mode Considerations
        4. 9.2.2.4 Resistor (R1, R2, R3, R4) Considerations
        5. 9.2.2.5 Noise and Input Impedance Considerations
        6. 9.2.2.6 First-order RC Filter Considerations
        7. 9.2.2.7 Circuit Implementation
        8. 9.2.2.8 Results Summary
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
    1. 10.1 Power-Supply Sequencing
    2. 10.2 Power-Supply Decoupling
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Related Links
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Community Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

9.2.2 Detailed Design Procedure

The first stage of the application circuit consists of an OPA333 in a noninverting summing amplifier configuration and serves two purposes:

  1. To level-shift the ground-referenced signal to allow bidirectional current measurements while running off a unipolar supply. The voltage across the shunt resistor, VSHUNT, is level-shifted by a common-mode voltage, VCM, as shown in Figure 29. The level-shifted voltage, VINX, at the noninverting input is given by Equation 3.
    2. Equation 3. VINX = (VCM · R3 + VSHUNT · R4) / (R3 + R4)
  2. To amplify the level-shifted voltage (VINX). The OPA333 is configured in a noninverting gain configuration with the output voltage, VOUT, given by Equation 4.
    3. Equation 4. VOUT = VINX · (1 + R2 / R1)

Using Equation 3 and Equation 4, VOUT is given as a function of VSHUNT and VCM by Equation 5.

Equation 5. VOUT = (VCM · R3 + VSHUNT · R4) / (R3 + R4) · (1 + R2 / R1)

Using Equation 5 the ADC differential input voltage, before the first-order RC filter, is given by Equation 6.

Equation 6. VOUT – VCM = VSHUNT · (1 + R2 / R1) / (1 + R4 / R3) + VCM · (R2 / R1 – R3 / R4) / (1 + R3 / R4)

If R1 = R3 and R2 = R4, Equation 6 is simplified to Equation 7.

Equation 7. VOUT – VCM = VSHUNT · (1 + R2 / R1) / (1 + R4 / R3)