SBAS565C January   2014  – August 2019 ADS1283

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
    1.     Simplified Schematic
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Timing Requirements
    7. 6.7 Switching Characteristics
    8. 6.8 Typical Characteristics
  7. 7 Parameter Measurement Information
    1. 7.1 Noise Performance
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Analog Inputs and Multiplexer
      2. 8.3.2 Programmable Gain Amplifier (PGA)
      3. 8.3.3 Analog-to-Digital Converter (ADC)
        1. 8.3.3.1 Modulator
          1. 8.3.3.1.1 Modulator Overrange
          2. 8.3.3.1.2 Modulator Input Impedance
          3. 8.3.3.1.3 Modulator Overrange Detection (MFLAG)
          4. 8.3.3.1.4 Offset
          5. 8.3.3.1.5 Voltage Reference Inputs (VREFP, VREFN)
        2. 8.3.3.2 Digital Filter
          1. 8.3.3.2.1 Sinc Filter Stage (sinx / x)
          2. 8.3.3.2.2 FIR Stage
          3. 8.3.3.2.3 Group Delay and Step Response
            1. 8.3.3.2.3.1 Linear Phase Response
            2. 8.3.3.2.3.2 Minimum Phase Response
          4. 8.3.3.2.4 HPF Stage
      4. 8.3.4 Master Clock Input (CLK)
    4. 8.4 Device Functional Modes
      1. 8.4.1  Synchronization (SYNC PIN and SYNC Command)
        1. 8.4.1.1 Pulse-Sync Mode
        2. 8.4.1.2 Continuous-Sync Mode
      2. 8.4.2  Reset (RESET Pin and Reset Command)
      3. 8.4.3  Power-Down (PWDN Pin and STANDBY Command)
      4. 8.4.4  Power-On Sequence
      5. 8.4.5  DVDD Power Supply
      6. 8.4.6  Serial Interface
        1. 8.4.6.1 Chip Select (CS)
        2. 8.4.6.2 Serial Clock (SCLK)
        3. 8.4.6.3 Data Input (DIN)
        4. 8.4.6.4 Data Output (DOUT)
        5. 8.4.6.5 Serial Port Auto Timeout
        6. 8.4.6.6 Data Ready (DRDY)
      7. 8.4.7  Data Format
      8. 8.4.8  Reading Data
        1. 8.4.8.1 Read-Data-Continuous Mode
        2. 8.4.8.2 Read-Data-By-Command Mode
      9. 8.4.9  One-Shot Operation
      10. 8.4.10 Offset and Full-Scale Calibration Registers
        1. 8.4.10.1 OFC[2:0] Registers
        2. 8.4.10.2 FSC[2:0] Registers
      11. 8.4.11 Calibration Commands (OFSCAL and GANCAL)
        1. 8.4.11.1 OFSCAL Command
        2. 8.4.11.2 GANCAL Command
      12. 8.4.12 User Calibration
    5. 8.5 Programming
      1. 8.5.1 Commands
        1. 8.5.1.1  SDATAC Requirements
        2. 8.5.1.2  WAKEUP: Wake-Up From Standby Mode
        3. 8.5.1.3  STANDBY: Standby Mode
        4. 8.5.1.4  SYNC: Synchronize the Analog-to-Digital Conversion
        5. 8.5.1.5  RESET: Reset the Device
        6. 8.5.1.6  RDATAC: Read Data Continuous
        7. 8.5.1.7  SDATAC: Stop Read Data Continuous
        8. 8.5.1.8  RDATA: Read Data by Command
        9. 8.5.1.9  RREG: Read Register Data
        10. 8.5.1.10 WREG: Write to Register
        11. 8.5.1.11 OFSCAL: Offset Calibration
        12. 8.5.1.12 GANCAL: Gain Calibration
    6. 8.6 Register Maps
      1. 8.6.1 Register Descriptions
        1. 8.6.1.1 ID_CFG: ID_Configuration Register (address = 00h) [reset =x0h]
        2. 8.6.1.2 CONFIG0: Configuration Register 0 (address = 01h) [reset = 52h]
        3. 8.6.1.3 CONFIG1: Configuration Register 1 (address = 02h) [reset = 08h]
        4. 8.6.1.4 HPF0 and HPF1 Registers
          1. 8.6.1.4.1 HPF0: High-Pass Filter Corner Frequency, Low Byte (address = 03h) [reset = 32h]
          2. 8.6.1.4.2 HPF1: High-Pass Filter Corner Frequency, High Byte (address = 04h) [reset = 03h]
        5. 8.6.1.5 OFC0, OFC1, OFC2 Registers
          1. 8.6.1.5.1 OFC0: Offset Calibration, Low Byte (address = 05h) [reset = 00h]
          2. 8.6.1.5.2 OFC1: Offset Calibration, Mid Byte (address = 06h) [reset = 00h]
          3. 8.6.1.5.3 OFC2: Offset Calibration, High Byte (address = 07h) [reset = 00h]
        6. 8.6.1.6 FSC0, FSC1, FSC2 Registers
          1. 8.6.1.6.1 FSC0: Full-Scale Calibration, Low Byte (address = 08h) [reset = 00h]
          2. 8.6.1.6.2 FSC1: Full-Scale Calibration, Mid Byte (address = 09h) [reset = 00h]
          3. 8.6.1.6.3 FSC2: Full-Scale Calibration, High Byte (address = 0Ah) [reset = 40h]
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Geophone Interface
      2. 9.2.2 Digital Interface
    3. 9.3 Initialization Set Up
  10. 10Device and Documentation Support
    1. 10.1 Receiving Notification of Documentation Updates
    2. 10.2 Community Resources
    3. 10.3 Trademarks
    4. 10.4 Electrostatic Discharge Caution
    5. 10.5 Glossary
  11. 11Mechanical, Packaging, and Orderable Information

Package Options

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

8.3.3.1.5 Voltage Reference Inputs (VREFP, VREFN)

The voltage reference for the ADS1283 is the differential voltage between VREFP and VREFN:

Equation 6. VREF = VREFP – VREFN

The reference inputs use a structure similar to that of the analog inputs with the circuitry of the reference inputs shown in Figure 34. The average load presented by the switched-capacitor reference input can be modeled with an effective differential impedance of:

Equation 7. REFF = tSAMPLE / CIN (tSAMPLE = 1 / fMOD).

Note that the effective impedance of the reference inputs loads the external reference.

ADS1283 ai_ref_in_cir_bas565.gifFigure 34. Simplified Reference Input Circuit

Place a 0.1-µF ceramic capacitor directly between the ADC VREFP and VREFN pins. Multiple ADC applications can share a single voltage reference, but must have individual capacitors placed for each ADC.

The ADS1283 reference inputs are protected by ESD diodes. In order to prevent these diodes from turning on, the voltage on either input must stay within the range shown in Equation 8:

Equation 8. ADS1283 q_avss_vref_bas418.gif

The minimum valid input for VREFN is AVSS – 0.1 V, and the maximum valid input for VREFP is AVDD + 0.1 V.

To achieve the best performance from the ADS1283, use a high-quality 5-V reference voltage. A 4-V or 4.5-V reference voltage can be used; however, this lower reference voltage reduces the signal input range with a corresponding decrease of SNR. Noise and drift on the reference degrade overall system performance. To achieve optimum performance, make sure to give special care to the circuitry generating the reference voltages. See the Application Information section for reference recommendations.