SBOS487B June   2009  – March 2020 PGA280

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Application
  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 Electrical Characteristics
    3. 6.3 Timing Requirements: Serial Interface
    4. 6.4 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Functional Blocks
        1. 7.3.1.1 Input Switch Network
        2. 7.3.1.2 Input Amplifier, Gain Network, and Buffer
        3. 7.3.1.3 Current Buffer
        4. 7.3.1.4 Input Protection
        5. 7.3.1.5 EMI Susceptibility
        6. 7.3.1.6 Output Stage
        7. 7.3.1.7 Output Filter
        8. 7.3.1.8 Single-Ended Output
        9. 7.3.1.9 Error Detection
      2. 7.3.2 Error Indicators
        1. 7.3.2.1 Input Clamp Conduction (ICAerr)
        2. 7.3.2.2 Input Overvoltage (IOVerr)
        3. 7.3.2.3 Gain Network Overload (GAINerr)
        4. 7.3.2.4 Output Amplifier (OUTerr)
        5. 7.3.2.5 CheckSum Error (CRCerr)
    4. 7.4 Device Functional Modes
      1. 7.4.1 GPIO Operation Mode
        1. 7.4.1.1 CS Mode
    5. 7.5 Programming
      1. 7.5.1 SPI and Register Description
      2. 7.5.2 Command Structure and Register Overview
        1. 7.5.2.1 Command Byte
        2. 7.5.2.2 Extended CS
          1. 7.5.2.2.1 SPI Timing Diagrams (Read and Write)
          2. 7.5.2.2.2 GPIO Pin Reference
          3. 7.5.2.2.3 Checksum
      3. 7.5.3 GPIO Configuration
      4. 7.5.4 Buffer Timing
    6. 7.6 Register Map
      1. 7.6.1  Register 0: Gain and External MUX Address (address = 00h) [reset = 0000 0000b]
      2. 7.6.2  Register 1: Software Reset Register (address = 01h) [reset = 0000 0000b]
      3. 7.6.3  Register 2: SPI: MODE Selection to GPIO-Pin (address = 02h) [reset = 0000 0000b]
      4. 7.6.4  Register 3: BUF Timeout Register (address = 03h) [reset = 0001 1001b]
      5. 7.6.5  Register 4: Error Register (address = 04h) [reset = 0000 0000b]
      6. 7.6.6  Register 5: GPIO Register (address = 05h) [reset = 0000 0000b]
      7. 7.6.7  Register 6: Input Switch Control Register 1 (address = 06h) [reset = 0110 0000b]
      8. 7.6.8  Register 7: Input Switch Control Register 2 (address =07h ) [reset = 0000 0000b]
      9. 7.6.9  Register 8: GPIO Configuration Register (address = 08h) [reset = 0000 0000b]
      10. 7.6.10 Register 9: CS Configuration Mode Register (address = 09h) [reset = 0000 0000b]
      11. 7.6.11 Register 10: Configuration Register 1 (address = 0Ah) [reset = 0000 0000b]
      12. 7.6.12 Register 11: Configuration Register 2 (address = 0Bh) [reset = 0001 0000b]
      13. 7.6.13 Register 12: Special Functions Register (address = 0Ch) [reset = 0000 0000b]
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 External Clock Synchronization
      2. 8.1.2 Quiescent Current
      3. 8.1.3 Settling Time
      4. 8.1.4 Overload Recovery
  9. 9 Power Supply Recommendations
  10. 10Device and Documentation Support
    1. 10.1 Receiving Notification of Documentation Updates
    2. 10.2 Support 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

7.1 Overview

The PGA280 is a universal high-voltage instrumentation amplifier with digital gain control. This device offers excellent dc precision and long-term stability using modern chopper technology with internal filters that minimize chopper-related noise. The input gain extends from ⅛ V/V (attenuation) to 128 V/V in binary steps. The output stage offers a gain multiplying factor of 1 V/V and 1⅜ V/V for optimal gain adjustment. The output stage connects to the low-voltage (5 V or 3 V) supply. .

A signal multiplexer provides two differential inputs. Several signal switches allow signal diagnosis of wire break, input disconnect, single-ended (versus differential), and shorted inputs.

The supply voltage of up to ±18 V offers a wide common-mode range with high input impedance; therefore, large common-mode noise signals and offsets can be suppressed.

A pair of high-speed current buffers can be activated to avoid inrush currents during fast signal transients, such as those generated from switching the signal multiplexers. This feature minimizes discharge errors in passive signal input filters in front of the multiplexer.

The fully differential signal output matches the inputs of modern high-resolution and high-accuracy analog-to-digital converters (ADCs), including delta-sigma (ΔΣ) as well as successive-approximation response (SAR) converters. The supply voltage for the output stage is normally connected together with the converter supply, thus preventing signal overloads from the high-voltage analog supply.

Internal error detection in the input and output stage provides individual information about the signal condition. Integrating ADCs may hide momentary overloads. Together with the input switch matrix, extensive signal and error diagnosis is made possible.

The serial peripheral interface (SPI) provides write and read access to internal registers. These registers control gain, the current buffer, input switches, and the general-purpose input/output (GPIO) or special function pins, as well as configuration and diagnostics.

The GPIO port controls the multiplexer (MUX) and switches and indicates internal conditions. The GPIO port can also be individually configured for output or input. A special CS mode for the GPIO extends the communication to other external SPI devices, such as data converters or shift registers. This special function is intended for SPI communication via a minimum number of isolation couplers. Additional proof for communication integrity is provided by an optional checksum byte following each communication block.