SBAS852A August   2017  – February 2020 ADS114S06B , ADS114S08B

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Functional Block Diagram
  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
    7. 7.7 Switching Characteristics
    8. 7.8 Typical Characteristics
  8. 8 Parameter Measurement Information
    1. 8.1 Noise Performance
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1  Multiplexer
      2. 9.3.2  Low-Noise Programmable Gain Amplifier
        1. 9.3.2.1 PGA Input-Voltage Requirements
        2. 9.3.2.2 Bypassing the PGA
      3. 9.3.3  Voltage Reference
        1. 9.3.3.1 Internal Reference
        2. 9.3.3.2 External Reference
        3. 9.3.3.3 Reference Buffers
      4. 9.3.4  Clock Source
      5. 9.3.5  Delta-Sigma Modulator
      6. 9.3.6  Digital Filter
        1. 9.3.6.1 Digital Filter Frequency Response
        2. 9.3.6.2 Data Conversion Time
        3. 9.3.6.3 Note on Conversion Time
        4. 9.3.6.4 50-Hz and 60-Hz Line Cycle Rejection
      7. 9.3.7  Excitation Current Sources (IDACs)
      8. 9.3.8  Bias Voltage Generation
      9. 9.3.9  System Monitor
        1. 9.3.9.1 Internal Temperature Sensor
        2. 9.3.9.2 Power Supply Monitors
        3. 9.3.9.3 Burn-Out Current Sources
      10. 9.3.10 Status Register
        1. 9.3.10.1 POR Flag
        2. 9.3.10.2 RDY Flag
        3. 9.3.10.3 External Reference Monitor
      11. 9.3.11 General-Purpose Inputs and Outputs (GPIOs)
      12. 9.3.12 Calibration
        1. 9.3.12.1 Offset Calibration
        2. 9.3.12.2 Gain Calibration
    4. 9.4 Device Functional Modes
      1. 9.4.1 Reset
        1. 9.4.1.1 Power-On Reset
        2. 9.4.1.2 RESET Pin
        3. 9.4.1.3 Reset by Command
      2. 9.4.2 Power-Down Mode
      3. 9.4.3 Standby Mode
      4. 9.4.4 Conversion Modes
        1. 9.4.4.1 Continuous Conversion Mode
        2. 9.4.4.2 Single-Shot Conversion Mode
    5. 9.5 Programming
      1. 9.5.1 Serial Interface
        1. 9.5.1.1 Chip Select (CS)
        2. 9.5.1.2 Serial Clock (SCLK)
        3. 9.5.1.3 Serial Data Input (DIN)
        4. 9.5.1.4 Serial Data Output and Data Ready (DOUT/DRDY)
        5. 9.5.1.5 Data Ready (DRDY)
        6. 9.5.1.6 Timeout
      2. 9.5.2 Data Format
      3. 9.5.3 Commands
        1. 9.5.3.1  NOP
        2. 9.5.3.2  WAKEUP
        3. 9.5.3.3  POWERDOWN
        4. 9.5.3.4  RESET
        5. 9.5.3.5  START
        6. 9.5.3.6  STOP
        7. 9.5.3.7  SYOCAL
        8. 9.5.3.8  SYGCAL
        9. 9.5.3.9  SFOCAL
        10. 9.5.3.10 RDATA
        11. 9.5.3.11 RREG
        12. 9.5.3.12 WREG
      4. 9.5.4 Interfacing with Multiple Devices
    6. 9.6 Register Map
      1. 9.6.1 Configuration Registers
      2. 9.6.2 Register Descriptions
        1. 9.6.2.1  Device ID Register (address = 00h) [reset = xxh]
          1. Table 16. Device ID (ID) Register Field Descriptions
        2. 9.6.2.2  Device Status Register (address = 01h) [reset = 80h]
          1. Table 17. Device Status (STATUS) Register Field Descriptions
        3. 9.6.2.3  Input Multiplexer Register (address = 02h) [reset = 01h]
          1. Table 18. Input Multiplexer (INPMUX) Register Field Descriptions
        4. 9.6.2.4  Gain Setting Register (address = 03h) [reset = 00h]
          1. Table 19. Gain Setting (PGA) Register Field Descriptions
        5. 9.6.2.5  Data Rate Register (address = 04h) [reset = 14h]
          1. Table 20. Data Rate (DATARATE) Register Field Descriptions
        6. 9.6.2.6  Reference Control Register (address = 05h) [reset = 10h]
          1. Table 21. Reference Control (REF) Register Field Descriptions
        7. 9.6.2.7  Excitation Current Register 1 (address = 06h) [reset = 00h]
          1. Table 22. Excitation Current Register 1 (IDACMAG) Register Field Descriptions
        8. 9.6.2.8  Excitation Current Register 2 (address = 07h) [reset = FFh]
          1. Table 23. Excitation Current Register 2 (IDACMUX) Register Field Descriptions
        9. 9.6.2.9  Sensor Biasing Register (address = 08h) [reset = 00h]
          1. Table 24. Sensor Biasing (VBIAS) Register Field Descriptions
        10. 9.6.2.10 System Control Register (address = 09h) [reset = 10h]
          1. Table 25. System Control (SYS) Register Field Descriptions
        11. 9.6.2.11 Reserved Register (address = 0Ah) [reset = 00h]
          1. Table 26. Reserved Register Field Descriptions
        12. 9.6.2.12 Offset Calibration Register 1 (address = 0Bh) [reset = 00h]
          1. Table 27. Offset Calibration Register 1 (OFCAL0) Register Field Descriptions
        13. 9.6.2.13 Offset Calibration Register 2 (address = 0Ch) [reset = 00h]
          1. Table 28. Offset Calibration Register 2 (OFCAL1) Register Field Descriptions
        14. 9.6.2.14 Reserved Register (address = 0Dh) [reset = 00h]
          1. Table 29. Reserved Register Field Descriptions
        15. 9.6.2.15 Gain Calibration Register 1 (address = 0Eh) [reset = 00h]
          1. Table 30. Gain Calibration Register 1 (FSCAL0) Field Descriptions
        16. 9.6.2.16 Gain Calibration Register 2 (address = 0Fh) [reset = 40h]
          1. Table 31. Gain Calibration Register 2 (FSCAL1) Field Descriptions
        17. 9.6.2.17 GPIO Data Register (address = 10h) [reset = 00h]
          1. Table 32. GPIO Data (GPIODAT) Register Field Descriptions
        18. 9.6.2.18 GPIO Configuration Register (address = 11h) [reset = 00h]
          1. Table 33. GPIO Configuration (GPIOCON) Register Field Descriptions
  10. 10Application and Implementation
    1. 10.1 Application Information
      1. 10.1.1 Serial Interface Connections
      2. 10.1.2 Analog Input Filtering
      3. 10.1.3 External Reference and Ratiometric Measurements
      4. 10.1.4 Establishing a Proper Input Voltage
      5. 10.1.5 Unused Inputs and Outputs
      6. 10.1.6 Pseudo Code Example
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Register Settings
      3. 10.2.3 Application Curves
    3. 10.3 What To Do and What Not To Do
  11. 11Power Supply Recommendations
    1. 11.1 Power Supplies
    2. 11.2 Power-Supply Sequencing
    3. 11.3 Power-On Reset
    4. 11.4 Power-Supply Decoupling
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Device Support
      1. 13.1.1 Development Support
    2. 13.2 Documentation Support
      1. 13.2.1 Related Documentation
    3. 13.3 Related Links
    4. 13.4 Receiving Notification of Documentation Updates
    5. 13.5 Community Resources
    6. 13.6 Trademarks
    7. 13.7 Electrostatic Discharge Caution
    8. 13.8 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • RHB|32
  • PBS|32
Thermal pad, mechanical data (Package|Pins)
Orderable Information

9.3.2 Low-Noise Programmable Gain Amplifier

The ADS114S06B and ADS114S08B feature a low-drift, low-noise, high input impedance programmable gain amplifier (PGA). Figure 43 shows a simplified diagram of the PGA. The PGA consists of two chopper-stabilized amplifiers (A1 and A2) and a resistor feedback network that sets the gain of the PGA. The PGA input is equipped with an electromagnetic interference (EMI) filter and an antialiasing filter on the output.

ADS114S06B ADS114S08B ai_pga_diagram_sbas660.gifFigure 43. Simplified PGA Diagram

The PGA can be set to gains of 1, 2, 4, 8, 16, 32, 64, or 128 using the GAIN[2:0] bits in the gain setting register (03h). Gain is changed inside the device using a variable resistor, RG. The differential full-scale input voltage range (FSR) of the PGA is defined by the gain setting and the reference voltage used, as shown in Equation 4:

Equation 4. FSR = ±VREF / Gain

Table 3 shows the corresponding full-scale ranges when using the internal 2.5-V reference.

Table 3. PGA Full-Scale Range

GAIN SETTING FSR
1 ±2.5 V
2 ±1.25 V
4 ±0.625 V
8 ±0.313 V
16 ±0.156 V
32 ±0.078 V
64 ±0.039 V
128 ±0.020 V

The PGA must be enabled with the PGA_EN[1:0] bits of the gain setting register (03h). Setting these bits to 00 powers down and bypasses the PGA. A setting of 01 enables the PGA. The 10 and 11 settings are reserved and must not be written to the device.

With the PGA enabled, gains 64 and 128 are established in the digital domain. When the device is set to 64 or 128, the PGA is set to a gain of 32, and additional gain is established with digital scaling. The input-referred noise does still improve compared to the gain = 32 setting because the PGA is biased with a higher supply current to reduce noise.