SBAS444E May   2009  – December 2024 ADS1113 , ADS1114 , ADS1115

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5.   Device Comparison Table
  6. 4 Pin Configuration and Functions
  7. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Timing Requirements: I2C
    7. 5.7 Typical Characteristics
  8. 6 Parameter Measurement Information
    1. 6.1 Noise Performance
  9. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagrams
    3. 7.3 Feature Description
      1. 7.3.1 Multiplexer
      2. 7.3.2 Analog Inputs
      3. 7.3.3 Full-Scale Range (FSR) and LSB Size
      4. 7.3.4 Voltage Reference
      5. 7.3.5 Oscillator
      6. 7.3.6 Output Data Rate and Conversion Time
      7. 7.3.7 Digital Comparator (ADS1114 and ADS1115 Only)
      8. 7.3.8 Conversion Ready Pin (ADS1114 and ADS1115 Only)
      9. 7.3.9 SMbus Alert Response
    4. 7.4 Device Functional Modes
      1. 7.4.1 Reset and Power-Up
      2. 7.4.2 Operating Modes
        1. 7.4.2.1 Single-Shot Mode
        2. 7.4.2.2 Continuous-Conversion Mode
      3. 7.4.3 Duty Cycling For Low Power
    5. 7.5 Programming
      1. 7.5.1 I2C Interface
        1. 7.5.1.1 I2C Address Selection
        2. 7.5.1.2 I2C General Call
        3. 7.5.1.3 I2C Speed Modes
      2. 7.5.2 Target Mode Operations
        1. 7.5.2.1 Receive Mode
        2. 7.5.2.2 Transmit Mode
      3. 7.5.3 Writing To and Reading From the Registers
      4. 7.5.4 Data Format
  10. 8 Registers
    1. 8.1 Register Map
      1. 8.1.1 Address Pointer Register (address = N/A) [reset = N/A]
      2. 8.1.2 Conversion Register (P[1:0] = 00b) [reset = 0000h]
      3. 8.1.3 Config Register (P[1:0] = 01b) [reset = 8583h]
      4. 8.1.4 Lo_thresh (P[1:0] = 10b) [reset = 8000h] and Hi_thresh (P[1:0] = 11b) [reset = 7FFFh] Registers
  11. 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 Quick-Start 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
  12. 10Power Supply Recommendations
    1. 10.1 Power-Supply Sequencing
    2. 10.2 Power-Supply Decoupling
  13. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  14. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Support Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  15. 13Revision History
  16. 14Mechanical, Packaging, and Orderable Information

Package Options

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

6.1 Noise Performance

Delta-sigma (ΔΣ) analog-to-digital converters (ADCs) are based on the principle of oversampling. The input signal of a ΔΣ ADC is sampled at a high frequency (modulator frequency) and subsequently filtered and decimated in the digital domain to yield a conversion result at the respective output data rate. The ratio between modulator frequency and output data rate is called oversampling ratio (OSR). By increasing the OSR, and thus reducing the output data rate, the noise performance of the ADC can be optimized. In other words, the input-referred noise drops when reducing the output data rate because more samples of the internal modulator are averaged to yield one conversion result. Increasing the gain also reduces the input-referred noise, which is particularly useful when measuring low-level signals.

Table 6-1 and Table 6-2 summarize the ADS111x noise performance. Data are representative of typical noise performance at TA = 25°C with the inputs shorted together externally. Table 6-1 shows the input-referred noise in units of μVRMS for the conditions shown. The µVPP values are shown in parentheses. Table 6-2 shows the effective resolution calculated from μVRMS values using Equation 1. The noise-free resolution calculated from peak-to-peak noise values using Equation 2 are shown in parentheses.

Equation 1. Effective Resolution = ln (FSR / VRMS-Noise) / ln(2)
Equation 2. Noise-Free Resolution = ln (FSR / VPP-Noise) / ln(2)
Table 6-1 Noise in μVRMS (μVPP) at VDD = 3.3V
DATA RATE
(SPS)		FSR (Full-Scale Range)
±6.144V±4.096V±2.048V±1.024V±0.512 V±0.256 V
8187.5 (187.5)125 (125)62.5 (62.5)31.25 (31.25)15.62 (15.62)7.81 (7.81)
16187.5 (187.5)125 (125)62.5 (62.5)31.25 (31.25)15.62 (15.62)7.81 (7.81)
32187.5 (187.5)125 (125)62.5 (62.5)31.25 (31.25)15.62 (15.62)7.81 (7.81)
64187.5 (187.5)125 (125)62.5 (62.5)31.25 (31.25)15.62 (15.62)7.81 (7.81)
128187.5 (187.5)125 (125)62.5 (62.5)31.25 (31.25)15.62 (15.62)7.81 (12.35)
250187.5 (252.09)125 (148.28)62.5 (84.03)31.25 (39.54)15.62 (16.06)7.81 (18.53)
475187.5 (266.92)125 (227.38)62.5 (79.08)31.25 (56.84)15.62 (32.13)7.81 (25.95)
860187.5 (430.06)125 (266.93)62.5 (118.63)31.25 (64.26)15.62 (40.78)7.81 (35.83)
Table 6-2 Effective Resolution from RMS Noise (Noise-Free Resolution from Peak-to-Peak Noise) at
VDD = 3.3V
DATA RATE
(SPS)		FSR (Full-Scale Range)
±6.144V±4.096V±2.048V±1.024V±0.512 V±0.256 V
816 (16)16 (16)16 (16)16 (16)16 (16)16 (16)
1616 (16)16 (16)16 (16)16 (16)16 (16)16 (16)
3216 (16)16 (16)16 (16)16 (16)16 (16)16 (16)
6416 (16)16 (16)16 (16)16 (16)16 (16)16 (16)
12816 (16)16 (16)16 (16)16 (16)16 (16)16 (15.33)
25016 (15.57)16 (15.75)16 (15.57)16 (15.66)16 (15.96)16 (14.75)
47516 (15.49)16 (15.13)16 (15.66)16 (15.13)16 (14.95)16 (14.26)
86016 (14.8)16 (14.9)16 (15.07)16 (14.95)16 (14.61)16 (13.8)