SBOS999A March   2022  – October 2022 INA851

PRODUCTION DATA  

  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Related Products
  6. Pin Configuration and Functions
  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 Typical Characteristics
  8. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Adjustable Gain Setting
        1. 8.3.1.1 Gain Drift
      2. 8.3.2 Offset Voltage
      3. 8.3.3 Input Common-Mode Range
      4. 8.3.4 Input Protection
      5. 8.3.5 Output Clamping
      6. 8.3.6 Low Noise
    4. 8.4 Device Functional Modes
  9. Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Output Common-Mode Pin
      2. 9.1.2 Output-Stage Gain Selection and Noise-Gain Shaping
      3. 9.1.3 Input Bias Current Return Path
      4. 9.1.4 Thermal Effects due to Power Dissipation
    2. 9.2 Typical Applications
      1. 9.2.1 Three-Pin Programmable Logic Controller (PLC)
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
        3. 9.2.1.3 Application Curves
      2. 9.2.2 20-Bit, 1-MSPS ADS8900B Driver Circuit With FDA Noise Filter
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Application Curves
      3. 9.2.3 24-Bit, 200 kSPS, Delta-Sigma ADS127L11 ADC Driver Circuit With FDA Noise Filter
        1. 9.2.3.1 Design Requirements
        2. 9.2.3.2 Application Curves
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  10. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Development Support
        1. 10.1.1.1 PSpice® for TI
        2. 10.1.1.2 TINA-TI™ Simulation Software (Free Download)
    2. 10.2 Documentation Support
      1. 10.2.1 Related Documentation
    3. 10.3 Receiving Notification of Documentation Updates
    4. 10.4 Support Resources
    5. 10.5 Trademarks
    6. 10.6 Electrostatic Discharge Caution
    7. 10.7 Glossary
  11. 11Mechanical, Packaging, and Orderable Information

Package Options

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

Design Requirements

The design requirements for the application driving the ADS127L11 ADC are listed in the following table.

Table 9-3 Design Parameters
PARAMETER VALUE
Differential-to-differential conversion VINDIFF to VOUTDIFF
Supply voltages VS± = ±15 V, AVDD = 5.2 V, VREF = 2.5 V
Full-scale range of ADC for FSR FSR = ± 5 V
Data rate of ADC fDATA = 187.5 kSPS
ADC filter configuration (1) High-speed mode, Sinc4 filter, OSR = 64
(2) High-speed mode, wideband filter, OSR = 64
INA gain and filter configuration See Table 9-4 and Table 9-5
Signal frequency fIN = 1 kHz
RC kickback filter(1) RFIL = 47.4 Ω + CDIFF = 510 pF + RFIL = 47.4 Ω, CFIL = 51 pF
A trade-off must be considered between THD, frequency response and drift. The differential current drift into the ADC can interact with this filter resistors and result in higher drift errors. However, low resistance degrades the phase margin of the INA851. For low drift applications, keep RFIL < 50 Ω.

For optimized linearity and THD performance, use good printed circuit board (PCB) layout practice. For proper heat dissipation of the INA851, connect the thermal pad to a plane or a large copper pour at the bottom connected to VS– (see also Section 9.4.2).