SLASF44A May   2023  – June 2024 AFE78201 , AFE88201

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
    7. 5.7  Timing Diagrams
    8. 5.8  Typical Characteristics: VOUT DAC
    9. 5.9  Typical Characteristics: ADC
    10. 5.10 Typical Characteristics: Reference
    11. 5.11 Typical Characteristics: Power Supply
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1  Digital-to-Analog Converter (DAC) Overview
        1. 6.3.1.1 DAC Resistor String
        2. 6.3.1.2 DAC Buffer Amplifier
        3. 6.3.1.3 DAC Transfer Function
        4. 6.3.1.4 DAC Gain and Offset Calibration
        5. 6.3.1.5 Programmable Slew Rate
        6. 6.3.1.6 DAC Register Structure and CLEAR State
      2. 6.3.2  Analog-to-Digital Converter (ADC) Overview
        1. 6.3.2.1 ADC Operation
        2. 6.3.2.2 ADC Custom Channel Sequencer
        3. 6.3.2.3 ADC Synchronization
        4. 6.3.2.4 ADC Offset Calibration
        5. 6.3.2.5 External Monitoring Inputs
        6. 6.3.2.6 Temperature Sensor
        7. 6.3.2.7 Self-Diagnostic Multiplexer
        8. 6.3.2.8 ADC Bypass
      3. 6.3.3  Programmable Out-of-Range Alarms
        1. 6.3.3.1 Alarm-Based Interrupts
        2. 6.3.3.2 Alarm Action Configuration Register
        3. 6.3.3.3 Alarm Voltage Generator
        4. 6.3.3.4 Temperature Sensor Alarm Function
        5. 6.3.3.5 Internal Reference Alarm Function
        6. 6.3.3.6 ADC Alarm Function
        7. 6.3.3.7 Fault Detection
      4. 6.3.4  IRQ
      5. 6.3.5  Internal Reference
      6. 6.3.6  Integrated Precision Oscillator
      7. 6.3.7  Precision Oscillator Diagnostics
      8. 6.3.8  One-Time Programmable (OTP) Memory
      9. 6.3.9  GPIO
      10. 6.3.10 Timer
      11. 6.3.11 Unique Chip Identifier (ID)
      12. 6.3.12 Scratch Pad Register
    4. 6.4 Device Functional Modes
      1. 6.4.1 Register Built-In Self-Test (RBIST)
      2. 6.4.2 DAC Power-Down Mode
      3. 6.4.3 Reset
    5. 6.5 Programming
      1. 6.5.1 Communication Setup
        1. 6.5.1.1 SPI Mode
        2. 6.5.1.2 UART Mode
      2. 6.5.2 GPIO Programming
      3. 6.5.3 Serial Peripheral Interface (SPI)
        1. 6.5.3.1 SPI Frame Definition
        2. 6.5.3.2 SPI Read and Write
        3. 6.5.3.3 Frame Error Checking
        4. 6.5.3.4 Synchronization
      4. 6.5.4 UART Interface
        1. 6.5.4.1 UART Break Mode (UBM)
      5. 6.5.5 Status Bits
      6. 6.5.6 Watchdog Timer
  8. 7 Register Maps
    1. 7.1 AFEx8201 Registers
  9. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Multichannel Configuration
    2. 8.2 Typical Application
      1. 8.2.1 Analog Output Module
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 XTR305
            1. 8.2.1.2.1.1 Current-Output Mode
            2. 8.2.1.2.1.2 Voltage Output Mode
            3. 8.2.1.2.1.3 Diagnostic Features
        3. 8.2.1.3 Application Curves
    3. 8.3 Initialization Setup
    4. 8.4 Power Supply Recommendations
    5. 8.5 Layout
      1. 8.5.1 Layout Guidelines
      2. 8.5.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Documentation Support
      1. 9.1.1 Related Documentation
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • RRU|24
Thermal pad, mechanical data (Package|Pins)
Orderable Information
8.2.1.2.1.2 Voltage Output Mode

For voltage-output mode, the 0-V to 2.5-V control input is translated to a ±11-V voltage output. Similar to current-output mode, a unipolar input is used to create a bipolar output. Figure 8-5 shows the configuration of the XTR305 in voltage-output mode.

AFE78201 AFE88201 The XTR305 Standard Circuit for Voltage Output Figure 8-5 The XTR305 Standard Circuit for Voltage Output

For voltage-output mode, OD is set high, while M1 and M2 are set low. The normal transfer function for this circuit is given in Equation 14.

Equation 14. V O U T = R G A I N 2 × V I N R S E T   +   V I N   –   V R E F R O S

Again, with RSET as an open circuit, the singular VIN term drops out. The gain is set by ROS and RGAIN as per Equation 15.

Equation 15. R G A I N = 2   × V o u t F S R ×   R O S V i n F S R = 2 × 22 × 499 2.5 = 8782   Ω

Select RGAIN = 8870 Ω, which gives a VoutFSR of 22.22 V, with an output range of ±11.11 V The transfer function is given by Equation 16.

Equation 16. V O U T = R G A I N 2 × V I N   –   V R E F R O S  

Using the AFE88201, the transfer function from code to output voltage is shown in Equation 17.

Equation 17. V O U T = R G A I N 2 × R O S × D A C _ C O D E   ×   2.5   V 2 16   – 1.25 V

When using the voltage-output mode, the output load current can be monitored through an analog output monitor in the XTR305. See also Section 8.2.1.2.1.3.