SBAS453G July   2009  – August 2016 ADS1146 , ADS1147 , ADS1148

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and 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 Diagrams
    3. 9.3 Feature Description
      1. 9.3.1  ADC Input and Multiplexer
      2. 9.3.2  Low-Noise PGA
        1. 9.3.2.1 PGA Common-Mode Voltage Requirements
        2. 9.3.2.2 PGA Common-Mode Voltage Calculation Example
        3. 9.3.2.3 Analog Input Impedance
      3. 9.3.3  Clock Source
      4. 9.3.4  Modulator
      5. 9.3.5  Digital Filter
      6. 9.3.6  Voltage Reference Input
      7. 9.3.7  Internal Voltage Reference
      8. 9.3.8  Excitation Current Sources
      9. 9.3.9  Sensor Detection
      10. 9.3.10 Bias Voltage Generation
      11. 9.3.11 General-Purpose Digital I/O
      12. 9.3.12 System Monitor
        1. 9.3.12.1 Power-Supply Monitor
        2. 9.3.12.2 External Voltage Reference Monitor
        3. 9.3.12.3 Ambient Temperature Monitor
    4. 9.4 Device Functional Modes
      1. 9.4.1 Power Up
      2. 9.4.2 Reset
      3. 9.4.3 Power-Down Mode
      4. 9.4.4 Conversion Control
        1. 9.4.4.1 Settling Time for Channel Multiplexing
        2. 9.4.4.2 Channel Cycling and Overload Recovery
        3. 9.4.4.3 Single-Cycle Settling
        4. 9.4.4.4 Digital Filter Reset Operation
      5. 9.4.5 Calibration
        1. 9.4.5.1 Offset Calibration Register: OFC[2:0]
        2. 9.4.5.2 Full-Scale Calibration Register: FSC[2:0]
        3. 9.4.5.3 Calibration Commands
          1. 9.4.5.3.1 System Offset and Self Offset Calibration
          2. 9.4.5.3.2 System Gain Calibration
        4. 9.4.5.4 Calibration Timing
    5. 9.5 Programming
      1. 9.5.1 Digital Interface
        1. 9.5.1.1 Chip Select (CS)
        2. 9.5.1.2 Serial Clock (SCLK)
        3. 9.5.1.3 Data Input (DIN)
        4. 9.5.1.4 Data Ready (DRDY)
        5. 9.5.1.5 Data Output and Data Ready (DOUT/DRDY)
        6. 9.5.1.6 SPI Reset
        7. 9.5.1.7 SPI Communication During Power-Down Mode
      2. 9.5.2 Data Format
      3. 9.5.3 Commands
        1. 9.5.3.1  WAKEUP (0000 000x)
        2. 9.5.3.2  SLEEP (0000 001x)
        3. 9.5.3.3  SYNC (0000 010x)
        4. 9.5.3.4  RESET (0000 011x)
        5. 9.5.3.5  RDATA (0001 001x)
        6. 9.5.3.6  RDATAC (0001 010x)
        7. 9.5.3.7  SDATAC (0001 011x)
        8. 9.5.3.8  RREG (0010 rrrr, 0000 nnnn)
        9. 9.5.3.9  WREG (0100 rrrr, 0000 nnnn)
        10. 9.5.3.10 SYSOCAL (0110 0000)
        11. 9.5.3.11 SYSGCAL (0110 0001)
        12. 9.5.3.12 SELFOCAL (0110 0010)
        13. 9.5.3.13 NOP (1111 1111)
        14. 9.5.3.14 Restricted Command (1111 0001)
    6. 9.6 Register Maps
      1. 9.6.1 ADS1146 Register Map
      2. 9.6.2 ADS1146 Detailed Register Definitions
        1. 9.6.2.1 BCS—Burn-out Current Source Register (offset = 00h) [reset = 01h]
        2. 9.6.2.2 VBIAS—Bias Voltage Register (offset = 01h) [reset = 00h]
        3. 9.6.2.3 MUX—Multiplexer Control Register (offset = 02h) [reset = x0h]
        4. 9.6.2.4 SYS0—System Control Register 0 (offset = 03h) [reset = 00h]
        5. 9.6.2.5 OFC—Offset Calibration Coefficient Registers (offset = 04h, 05h, 06h) [reset = 00h, 00h, 00h]
        6. 9.6.2.6 FSC—Full-Scale Calibration Coefficient Registers (offset = 07h, 08h, 09h) [reset = 00h, 00h, 40h]
        7. 9.6.2.7 ID—ID Register (offset = 0Ah) [reset = x0h]
      3. 9.6.3 ADS1147 and ADS1148 Register Map
      4. 9.6.4 ADS1147 and ADS1148 Detailed Register Definitions
        1. 9.6.4.1  MUX0—Multiplexer Control Register 0 (offset = 00h) [reset = 01h]
        2. 9.6.4.2  VBIAS—Bias Voltage Register (offset = 01h) [reset = 00h]
        3. 9.6.4.3  MUX1—Multiplexer Control Register 1 (offset = 02h) [reset = x0h]
        4. 9.6.4.4  SYS0—System Control Register 0 (offset = 03h) [reset = 00h]
        5. 9.6.4.5  OFC—Offset Calibration Coefficient Register (offset = 04h, 05h, 06h) [reset = 00h, 00h, 00h]
        6. 9.6.4.6  FSC—Full-Scale Calibration Coefficient Register (offset = 07h, 08h, 09h) [reset = 00h, 00h, 40h]
        7. 9.6.4.7  IDAC0—IDAC Control Register 0 (offset = 0Ah) [reset = x0h]
        8. 9.6.4.8  IDAC1—IDAC Control Register 1 (offset = 0Bh) [reset = FFh]
        9. 9.6.4.9  GPIOCFG—GPIO Configuration Register (offset = 0Ch) [reset = 00h]
        10. 9.6.4.10 GPIODIR—GPIO Direction Register (offset = 0Dh) [reset = 00h]
        11. 9.6.4.11 GPIODAT—GPIO Data Register (offset = 0Eh) [reset = 00h]
  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 Common-Mode Input Voltage
      5. 10.1.5 Isolated (or Floating) Sensor Inputs
      6. 10.1.6 Unused Inputs and Outputs
      7. 10.1.7 Pseudo Code Example
      8. 10.1.8 Channel Multiplexing Example
      9. 10.1.9 Power-Down Mode Example
    2. 10.2 Typical Applications
      1. 10.2.1 Ratiometric 3-Wire RTD Measurement System
        1. 10.2.1.1 Design Requirements
        2. 10.2.1.2 Detailed Design Procedure
          1. 10.2.1.2.1 Topology
          2. 10.2.1.2.2 RTD Selection
          3. 10.2.1.2.3 Excitation Current
          4. 10.2.1.2.4 Reference Resistor, RREF
          5. 10.2.1.2.5 PGA Setting
          6. 10.2.1.2.6 Common-Mode Input Range
          7. 10.2.1.2.7 Input and Reference Low-Pass Filters
          8. 10.2.1.2.8 Register Settings
        3. 10.2.1.3 Application Curves
      2. 10.2.2 K-Type Thermocouple Measurement (-200°C to 1250°C) With Cold-Junction Compensation
        1. 10.2.2.1 Design Requirements
        2. 10.2.2.2 Detailed Design Procedure
          1. 10.2.2.2.1 Biasing Resistors
          2. 10.2.2.2.2 Input Filtering
          3. 10.2.2.2.3 PGA Setting
          4. 10.2.2.2.4 Cold-Junction Measurement
          5. 10.2.2.2.5 Calculated Resolution
          6. 10.2.2.2.6 Register Settings
    3. 10.3 Do's and Don'ts
  11. 11Power Supply Recommendations
    1. 11.1 Power Supply Sequencing
    2. 11.2 Power Supply Decoupling
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Documentation Support
      1. 13.1.1 Related Documentation
    2. 13.2 Related Links
    3. 13.3 Receiving Notification of Documentation Updates
    4. 13.4 Community Resources
    5. 13.5 Trademarks
    6. 13.6 Electrostatic Discharge Caution
    7. 13.7 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

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

1 Features

  • Programmable Data Rates Up to 2 kSPS
  • Single-Cycle Settling for All Data Rates
  • Simultaneous 50-Hz and 60-Hz Rejection at
    20 SPS
  • Analog Multiplexer With 8 (ADS1148) and
    4 (ADS1147) Independently Selectable Inputs
  • Programmable Gain: 1 V/V to 128 V/V
  • Dual-Matched Programmable Excitation Current Sources
  • Low-Drift Internal 2.048-V Reference
  • Sensor Burnout Detection
  • 4 or 8 General-Purpose I/Os (ADS1147 and ADS1148)
  • Internal Temperature Sensor
  • Power Supply and VREF Monitoring (ADS1147 and ADS1148)
  • Self and System Calibration
  • SPI™-Compatible Serial Interface
  • Analog Supply: Unipolar (2.7 V to 5.25 V) or Bipolar (±2.5 V)
  • Digital Supply: 2.7 V to 5.25 V

2 Applications

  • Temperature Measurement
    • RTDs, Thermocouples, and Thermistors
  • Pressure Measurement
  • Flow Meters
  • Factory Automation and Process Control

3 Description

The ADS1146, ADS1147, and ADS1148 devices are precision, 16-bit analog-to-digital converters (ADCs) that include many integrated features to reduce system cost and component count for sensor measurement applications. The devices feature a low-noise, programmable gain amplifier (PGA), a precision delta-sigma (ΔΣ) ADC with a single-cycle settling digital filter, and an internal oscillator. The ADS1147 and ADS1148 devices also provide a built-in, low-drift voltage reference, and two matched programmable excitation current sources (IDACs).

An input multiplexer supports four differential inputs for the ADS1148, two for the ADS1147, and one for the ADS1146. In addition, the multiplexer integrates sensor burn-out detection, voltage bias for thermocouples, system monitoring, and general purpose digital I/Os (ADS1147 and ADS1148). The PGA provides selectable gains up to 128 V/V. These features provide a complete front-end solution for temperature sensor measurement applications including thermocouples, thermistors, and resistance temperature detectors (RTDs) and other small signal measurements including resistive bridge sensors. The digital filter settles in a single cycle to support fast channel cycling when using the input multiplexer and provides data rates up to 2 kSPS. For data rates of 20 SPS or less, both 50-Hz and 60-Hz interference are rejected by the filter.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
ADS1146 TSSOP (16) 5.00 mm × 4.40 mm
ADS1147 TSSOP (20) 6.50 mm × 4.40 mm
ADS1148 TSSOP (28) 9.70 mm × 4.40 mm
VQFN (32) 5.00 mm × 5.00 mm
  1. For all available packages, see the orderable addendum at the end of the datasheet.

Functional Block Diagrams

ADS1146 ADS1147 ADS1148 ai_46_47_48_fbd_new_sbas453.gif