SBAS559B May   2022  – November 2025 ADS1285

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Timing Requirements: 1.65V ≤ IOVDD ≤ 1.95V and 2.7V ≤ IOVDD ≤ 3.6V
    7. 5.7 Switching Characteristics: 1.65V ≤ IOVDD ≤ 1.95V and 2.7V ≤ IOVDD ≤ 3.6V
    8. 5.8 Timing Diagrams
    9. 5.9 Typical Characteristics
  7. 6 Parameter Measurement Information
    1. 6.1 Noise Performance
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Analog Input
      2. 7.3.2 PGA and Buffer
        1. 7.3.2.1 Programmable Gain Amplifier (PGA)
        2. 7.3.2.2 Buffer Operation (PGA Bypass)
      3. 7.3.3 Voltage Reference Input
      4. 7.3.4 IOVDD Power Supply
      5. 7.3.5 Modulator
        1. 7.3.5.1 Modulator Overdrive
      6. 7.3.6 Digital Filter
        1. 7.3.6.1 Sinc Filter Section
        2. 7.3.6.2 FIR Filter Section
        3. 7.3.6.3 Group Delay and Step Response
          1. 7.3.6.3.1 Linear Phase Response
          2. 7.3.6.3.2 Minimum Phase Response
        4. 7.3.6.4 HPF Stage
      7. 7.3.7 Clock Input
      8. 7.3.8 GPIO
    4. 7.4 Device Functional Modes
      1. 7.4.1 Power Modes
      2. 7.4.2 Power-Down Mode
      3. 7.4.3 Reset
      4. 7.4.4 Synchronization
        1. 7.4.4.1 Pulse-Sync Mode
        2. 7.4.4.2 Continuous-Sync Mode
      5. 7.4.5 Sample Rate Converter
      6. 7.4.6 Offset and Gain Calibration
        1. 7.4.6.1 OFFSET Register
        2. 7.4.6.2 GAIN Register
        3. 7.4.6.3 Calibration Procedure
    5. 7.5 Programming
      1. 7.5.1 Serial Interface
        1. 7.5.1.1 Chip Select (CS)
        2. 7.5.1.2 Serial Clock (SCLK)
        3. 7.5.1.3 Data Input (DIN)
        4. 7.5.1.4 Data Output (DOUT)
        5. 7.5.1.5 Data Ready (DRDY)
      2. 7.5.2 Conversion Data Format
      3. 7.5.3 Commands
        1. 7.5.3.1  Single Byte Command
        2. 7.5.3.2  WAKEUP: Wake Command
        3. 7.5.3.3  STANDBY: Software Power-Down Command
        4. 7.5.3.4  SYNC: Synchronize Command
        5. 7.5.3.5  RESET: Reset Command
        6. 7.5.3.6  Read Data Direct
        7. 7.5.3.7  RDATA: Read Conversion Data Command
        8. 7.5.3.8  RREG: Read Register Command
        9. 7.5.3.9  WREG: Write Register Command
        10. 7.5.3.10 OFSCAL: Offset Calibration Command
        11. 7.5.3.11 GANCAL: Gain Calibration Command
    6. 7.6 Register Map
      1. 7.6.1 Register Descriptions
        1. 7.6.1.1 ID/SYNC: Device ID, SYNC Register (Address = 00h) [Reset = xxxx0000b]
        2. 7.6.1.2 CONFIG0: Configuration Register 0 (Address = 01h) [Reset = 12h]
        3. 7.6.1.3 CONFIG1: Configuration Register 1 (Address = 02h) [Reset = 00h]
        4. 7.6.1.4 HPF0, HPF1: High-Pass Filter Registers (Address = 03h, 04h) [Reset = 32h, 03h]
        5. 7.6.1.5 OFFSET0, OFFSET1, OFFSET2: Offset Calibration Registers (Address = 05h, 06h, 07h) [Reset = 00h, 00h, 00h]
        6. 7.6.1.6 GAIN0, GAIN1, GAIN2: Gain Calibration Registers (Address = 08h, 09h, 0Ah) [Reset = 00h, 00h, 40h]
        7. 7.6.1.7 GPIO: Digital Input/Output Register (Address = 0Bh) [Reset = 000xx000b]
        8. 7.6.1.8 SRC0, SRC1: Sample Rate Converter Registers (Address = 0Ch, 0Dh) [Reset = 00h, 80h]
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
      1. 8.3.1 Analog Power Supplies
      2. 8.3.2 Digital Power Supply
      3. 8.3.3 Grounds
      4. 8.3.4 Thermal Pad
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Receiving Notification of Documentation Updates
    2. 9.2 Support Resources
    3. 9.3 Trademarks
    4. 9.4 Electrostatic Discharge Caution
    5. 9.5 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

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

8.3.1 Analog Power Supplies

The ADC has three analog power supplies, AVDD1, AVDD2, and AVSS, all of which must be well regulated and free from switching power-supply noise (voltage ripple < 1mV). The AVDD1 power-supply voltage is relative to AVSS and powers the PGA and buffer. AVSS is the negative power supply. The ADC can be configured for single-supply operation with AVDD1 = 5V or 3.3V with AVSS connected to ground. Because the minimum voltage of AVDD1 to AGND = 2.375V, dual-supply operation is only possible when AVDD1 – AVSS = ±2.5V. Single-power supply operation requires a level-shift voltage at the geophone input through the input termination resistors. The level-shift voltage is typically equal to AVDD1 / 2. Bypass AVDD1 with 1μF and 0.1μF parallel capacitors to AVSS.

The AVDD2 power supply powers the modulator. To simplify system power management, AVDD2 can be connected AVDD1, regardless whether AVDD1 and AVSS are configured for single- or dual-supply operation (AVDD2 voltage range is 2.375V to 5.25V with respect to AGND). Bypass AVDD2 with 1μF and 0.1μF parallel capacitors to AGND.