SBASAC1A august   2021  – july 2023 AFE439A2 , AFE539A4 , AFE639D2

PRODUCTION DATA  

  1.   1
  2. Features
  3. Applications
  4. Description
  5. Revision History
  6. Pin Configuration and Functions
  7. 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: Voltage Output
    6. 6.6  Electrical Characteristics: Comparator Mode
    7. 6.7  Electrical Characteristics: ADC Input
    8. 6.8  Electrical Characteristics: General
    9. 6.9  Timing Requirements: I2C Standard Mode
    10. 6.10 Timing Requirements: I2C Fast Mode
    11. 6.11 Timing Requirements: I2C Fast Mode Plus
    12. 6.12 Timing Requirements: SPI Write Operation
    13. 6.13 Timing Requirements: SPI Read and Daisy Chain Operation (FSDO = 0)
    14. 6.14 Timing Requirements: SPI Read and Daisy Chain Operation (FSDO = 1)
    15. 6.15 Timing Requirements: PWM Output
    16. 6.16 Timing Requirements: I2C Controller
    17. 6.17 Timing Diagrams
    18. 6.18 Typical Characteristics: Voltage Output
    19. 6.19 Typical Characteristics: ADC
    20. 6.20 Typical Characteristics: Comparator
    21. 6.21 Typical Characteristics: General
  8. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagrams
    3. 7.3 Feature Description
      1. 7.3.1 Smart Analog Front End (AFE) Architecture
      2. 7.3.2 Programming Interface
      3. 7.3.3 Nonvolatile Memory (NVM)
        1. 7.3.3.1 NVM Cyclic Redundancy Check (CRC)
          1. 7.3.3.1.1 NVM-CRC-FAIL-USER Bit
          2. 7.3.3.1.2 NVM-CRC-FAIL-INT Bit
      4. 7.3.4 Power-On Reset (POR)
      5. 7.3.5 External Reset
      6. 7.3.6 Register-Map Lock
    4. 7.4 Device Functional Modes
      1. 7.4.1 Voltage-Output Mode
      2. 7.4.2 Voltage Reference and DAC Transfer Function
        1. 7.4.2.1 Power-Supply as Reference
        2. 7.4.2.2 Internal Reference
        3. 7.4.2.3 External Reference
      3. 7.4.3 Comparator Mode
      4. 7.4.4 Analog-to-Digital Converter (ADC) Mode
      5. 7.4.5 Pulse-Width Modulation (PWM)
      6. 7.4.6 Proportional-Integral (PI) Control
        1. 7.4.6.1 AFE439A2 PI Control
        2. 7.4.6.2 AFE539A4 PI Control
        3. 7.4.6.3 AFE639D2 PI Control
    5. 7.5 Programming
      1. 7.5.1 SPI Programming Mode
      2. 7.5.2 I2C Programming Mode
        1. 7.5.2.1 F/S Mode Protocol
        2. 7.5.2.2 I2C Update Sequence
          1. 7.5.2.2.1 Address Byte
          2. 7.5.2.2.2 Command Byte
        3. 7.5.2.3 I2C Read Sequence
    6. 7.6 Register Maps
      1. 7.6.1  NOP Register (address = 00h) [reset = 0000h]
      2. 7.6.2  DAC-x-VOUT-CMP-CONFIG Register (address = 03h, 09h, 0Fh, 15h)
      3. 7.6.3  COMMON-CONFIG Register (address = 1Fh)
      4. 7.6.4  COMMON-TRIGGER Register (address = 20h) [reset = 0000h]
      5. 7.6.5  COMMON-PWM-TRIG Register (address = 21h) [reset = 0000h]
      6. 7.6.6  GENERAL-STATUS Register (address = 22h) [reset = 00h, DEVICE-ID, VERSION-ID]
      7. 7.6.7  INTERFACE-CONFIG Register (address = 26h) [reset = 0000h]
      8. 7.6.8  STATE-MACHINE-CONFIG0 Register (address = 27h) [reset = 0003h]
      9. 7.6.9  STATE-MACHINE-CONFIG1 Register (address = 29h) [reset = C800h]
      10. 7.6.10 SRAM-CONFIG Register (address = 2Bh) [reset = 0000h]
      11. 7.6.11 SRAM-DATA Register (address = 2Ch) [reset = 0000h]
  9. 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
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 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. 10Mechanical, Packaging, and Orderable Information

I2C Programming Mode

The AFEx39xx devices have a 2-wire serial interface (SCL and SDA), and one address pin (A0), as shown in the pin diagram in the Pin Configuration and Functions section. The I2C bus consists of a data line (SDA) and a clock line (SCL) with pullup structures. When the bus is idle, both SDA and SCL lines are pulled high. All the I2C-compatible devices connect to the I2C bus through the open drain I/O pins, SDA and SCL.

The I2C specification states that the device that controls communication is called a controller, and the devices that are controlled by the controller are called targets. The controller generates the SCL signal. The controller also generates special timing conditions (start condition, repeated start condition, and stop condition) on the bus to indicate the start or stop of a data transfer. Device addressing is completed by the controller. The controller on an I2C bus is typically a microcontroller or digital signal processor (DSP). The AFEx39xx family operates as a target on the I2C bus. A target acknowledges controller commands, and upon controller control, receives or transmits data.

Typically, the AFEx39xx family operates as a target receiver. A controller writes to the AFEx39xx, a target receiver. However, if a controller requires the AFEx39xx internal register data, the AFEx39xx operate as a target transmitter. In this case, the controller reads from the AFEx39xx. According to I2C terminology, read and write refer to the controller.

The AFEx39xx family supports the following data transfer modes:

  • Standard mode (100Kbps)
  • Fast mode (400Kbps)
  • Fast mode plus (1.0Mbps)

The data transfer protocol for standard and fast modes is exactly the same; therefore, both modes are referred to as F/S-mode in this document. The fast mode plus protocol is supported in terms of data transfer speed, but not output current. The low-level output current is 3 mA; similar to the case of standard and fast modes. The AFEx39xx family supports 7-bit addressing. The 10-bit addressing mode is not supported. The device supports the general call reset function. Sending the following sequence initiates a software reset within the device: start or repeated start, 0x00, 0x06, stop. The reset is asserted within the device on the rising edge of the ACK bit, following the second byte.

Other than specific timing signals, the I2C interface works with serial bytes. At the end of each byte, a ninth clock cycle generates and detects an acknowledge signal. An acknowledge is when the SDA line is pulled low during the high period of the ninth clock cycle. A not-acknowledge is when the SDA line is left high during the high period of the ninth clock cycle, as shown in Figure 7-14.

GUID-20211130-SS0I-WJVK-SQZ5-V6KZDFVZF0MG-low.svg Figure 7-14 Acknowledge and Not Acknowledge on the I2C Bus