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

6 Pin Configuration and Functions

PW Package
16-Pin TSSOP
Top View
PW Package
20-Pin TSSOP
Top View
PW Package
28-Pin TSSOP
Top View
RHB Package
32-Pin VQFN
Top View

Pin Functions

PIN TYPE(1) DESCRIPTION(2)
NAME ADS1146 ADS1147 ADS1148
TSSOP (16) TSSOP (20) TSSOP (28) VQFN (32)
AIN0/IEXC — 9 11 17 I Analog input 0, optional excitation current output
AIN1/IEXC — 10 12 18 I Analog input 1, optional excitation current output
AIN2/IEXC/GPIO2 — 11 17 23 I/O Analog input 2, optional excitation current output,
or general-purpose digital input/output pin 2
AIN3/IEXC/GPIO3 — 12 18 24 I/O Analog input 3, optional excitation current output,
or general-purpose digital input/output pin 3
AIN4/IEXC/GPIO4 — — 13 19 I/O Analog input 4, optional excitation current output,
or general-purpose digital input/output pin 4
AIN5/IEXC/GPIO5 — — 14 20 I/O Analog input 5, optional excitation current output,
or general-purpose digital input/output pin 5
AIN6/IEXC/GPIO6 — — 15 21 I/O Analog input 6, optional excitation current output,
or general-purpose digital input/output pin 6
AIN7/IEXC/GPIO7 — — 16 22 I/O Analog input 7, optional excitation current output,
or general-purpose digital input/output pin 7
AINN 8 — — — I Negative analog input
AINP 7 — — — I Positive analog input
AVDD 10 14 22 28 P Positive analog power supply, connect a 0.1-µF capacitor to AVSS
AVSS 9 13 21 27 P Negative analog power supply
CLK 3 3 3 9 I External clock input, tie to DGND to activate the internal oscillator.
CS 12 16 24 30 I Chip select (active low)
DGND 2 2 2 8 G Digital ground
DIN 15 19 27 1 I Serial data input
DOUT/DRDY 14 18 26 32 O Serial data output, or data out combined with data ready
DRDY 13 17 25 31 O Data ready (active low)
DVDD 1 1 1 7 P Digital power supply, connect a 0.1-µF capacitor to DGND
IEXC1 — — 20 26 O Excitation current output 1
IEXC2 — — 19 25 O Excitation current output 2
NC — — — 3, 4, 5, 6 — Connect pin to AVSS or leave floating
REFN 6 — — — I Negative external reference input
REFN0/GPIO1 — 6 6 12 I/O Negative external reference input 0,
or general-purpose digital input/output pin 1
REFN1 — — 8 14 I Negative external reference input 1
REFP 5 — — — I Positive external reference input
REFP0/GPIO0 — 5 5 11 I/O Positive external reference input 0,
or general-purpose digital input/output pin 1
REFP1 — — 7 13 I Positive external reference input 1
RESET 4 4 4 10 I Reset (active low)
SCLK 16 20 28 2 I Serial clock input
START 11 15 23 29 I Conversion start
Thermal Pad — — — 33 — Connect pin to AVSS or leave floating
VREFCOM — 8 10 16 O Negative internal reference voltage output, connect to AVSS when using a unipolar supply or to the mid-voltage ground when using a bipolar supply
VREFOUT — 7 9 15 O Positive internal reference voltage output, connect a capacitor in the range of 1 µF to 47 µF to VREFCOM
(1) G = Ground, I = Input, O = Output, P = Power
(2) See Unused Inputs and Outputs for unused pin connections.