SLAT163 July   2024 AFE43902-Q1 , AFE439A2 , AFE53902-Q1 , AFE539A4 , AFE539F1-Q1 , AFE639D2 , DAC43204 , DAC43401 , DAC43401-Q1 , DAC43701 , DAC43701-Q1 , DAC43901-Q1 , DAC43902-Q1 , DAC53001 , DAC53002 , DAC53004 , DAC53004W , DAC53202 , DAC53204 , DAC53204-Q1 , DAC53204W , DAC53401 , DAC53401-Q1 , DAC53701-Q1 , DAC539E4W , DAC539G2-Q1 , DAC63001 , DAC63002 , DAC63004 , DAC63004W , DAC63202 , DAC63202W , DAC63204 , DAC63204-Q1 , DAC63204W

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1What is a Smart DAC?
  5. 2What is a Smart Analog Front End (AFE)?
  6. 3Smart DAC selection guide
  7. 4Smart AFE Selection Guide
  8. 5Applications
    1. 5.1 Lightning
      1. 5.1.1 Light Emitting Diode (LED) Biasing and Linear Fade-In Fade-Out
      2. 5.1.2 LED Biasing With LED Driver
      3. 5.1.3 Analog Thermal Foldback
        1. 5.1.3.1 Single Slope Thermal Foldback
        2. 5.1.3.2 Multi-Slope Thermal Foldback
      4. 5.1.4 Logarithmic Fade-In/Fade-Out
      5. 5.1.5 LED Sequencing
    2. 5.2 Control
      1. 5.2.1 Voltage Margining and Scaling With Voltage Output Smart DAC
      2. 5.2.2 Thermoelectric Cooling (TEC) Control
        1. 5.2.2.1 TEC Control Using DC/DC Driver
        2. 5.2.2.2 TEC control using h-Bridge driver
      3. 5.2.3 Analog Power Control (APC) of a Laser
      4. 5.2.4 Constant Power Control
    3. 5.3 Microcontroller Independent Fault Management and Communication
      1. 5.3.1 Programmable Comparator Using Smart DAC
      2. 5.3.2 GPI-to-PWM
      3. 5.3.3 If-Then-Else Logic
    4. 5.4 Driver
      1. 5.4.1 Lens Positioning Control for Camera Module Auto-Focus and Image Stabilization
      2. 5.4.2 Laser Drive
    5. 5.5 Miscellaneous Smart DAC Applications
      1. 5.5.1 Software-less Medical Alarm Generation
      2. 5.5.2 555 Timer

2 What is a Smart Analog Front End (AFE)?

Real-time control loops are often implemented with external hardware and an MCU. Such implementation often requires a variety of discrete components for sensing, filtering, and a control routine mechanism implemented with a micro-controller. Such systems however add complex research and development cycles. In the event of a system upgrade - changes to the regulatory upgrade or system design, software controlled systems are often not reusable. To simplify this, Texas Instruments released smart AFEs which are the devices that contain all of the smart DAC features with additional:

  • An integrated and programmable state machine
  • An integrated digital or analog sensing mechanism
  • Programmable look-up table
  • Non-volatile memory to store configurations

Smart AFEs incorporate both a sensing and a controlling mechanism in one chip to remove the need for additional discrete components. With NVM and a variety of configurable tools, smart AFEs eliminate the need for run-time software and can be configured directly by a hardware engineer.

By offloading the real-time logic to the hardware, the system becomes modular and concurrent, allowing the individual blocks to be loosely coupled and replaced without the need to update adjacent blocks. An upgrade of hardware in the system or an addition regulatory requirements does not affect the real-time logic and controlling loop, making the design significantly more versatile compared to the standard MCU approach.

For the subsystems that require run-time updates - smart AFEs also support such requirements by having a versatile and auto detecting SPI and I2C communication protocols available. AFE block diagram gives an example of a common smart AFE.

AFE Block Diagram Figure 2-1 AFE Block Diagram

Due to the fact that the control is offloaded from the micro-controller and is independent from the driver and the load - in the event of a hardware update or in case of a supply shortage when needing a hardware replacement - there is no need for a software update since the control loop remains the same.