SBAS650C May   2014  – April 2021 AFE4403

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Family Options
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Timing Requirements
    7. 7.7 Timing Requirements: Supply Ramp and Power-Down
    8. 7.8 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Receiver Channel
        1. 8.3.1.1 Receiver Front-End
        2. 8.3.1.2 Ambient Cancellation Scheme and Second Stage Gain Block
        3. 8.3.1.3 Receiver Control Signals
        4. 8.3.1.4 Receiver Timing
      2. 8.3.2 Clocking and Timing Signal Generation
      3. 8.3.3 Timer Module
        1. 8.3.3.1 Using the Timer Module
      4. 8.3.4 Receiver Subsystem Power Path
      5. 8.3.5 Transmit Section
        1. 8.3.5.1 Third LED Support
        2. 8.3.5.2 Transmitter Power Path
        3. 8.3.5.3 LED Power Reduction During Periods of Inactivity
        4. 8.3.5.4 LED Configurations
    4. 8.4 Device Functional Modes
      1. 8.4.1 ADC Operation and Averaging Module
        1. 8.4.1.1 Operation Without Averaging
        2. 8.4.1.2 Operation With Averaging
        3. 8.4.1.3 Dynamic Power-Down Mode
      2. 8.4.2 Diagnostics
        1. 8.4.2.1 Photodiode-Side Fault Detection
        2. 8.4.2.2 Transmitter-Side Fault Detection
        3. 8.4.2.3 Diagnostics Module
    5. 8.5 Programming
      1. 8.5.1 Serial Programming Interface
      2. 8.5.2 Reading and Writing Data
        1. 8.5.2.1 Writing Data
        2. 8.5.2.2 Reading Data
        3. 8.5.2.3 Multiple Data Reads and Writes
        4. 8.5.2.4 Register Initialization
        5. 8.5.2.5 AFE SPI Interface Design Considerations
    6. 8.6 Register Maps
      1. 8.6.1 AFE Register Map
      2. 8.6.2 AFE Register Description
  9. 9 Application Information Disclaimer
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
    1. 10.1 Power Consumption Considerations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Trademarks
    2. 12.2 Electrostatic Discharge Caution
    3. 12.3 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

7.7 Timing Requirements: Supply Ramp and Power-Down

PARAMETERVALUE
t1Time between Rx and Tx supplies ramping upKeep as small as possible (for example, ±10 ms)
t2Time between both supplies stabilizing and high-going RESET edge> 100 ms
t3RESET pulse duration> 0.5 ms
t4Time between RESET and SPI commands> 1 µs
t5Time between SPI commands and the ADC_ RESET which corresponds to valid data> 3 ms of cumulative sampling time in each phase(1)(2)(3)
t6Time between RESET pulse and high-accuracy data coming out of the signal chain> 1 s(3)
t7Time from AFE_ PDN high-going edge and RESET pulse(4)> 100 ms
t8Time from AFE_ PDN high-going edge (or PDN_AFE bit reset) to high-accuracy data coming out of the signal chain> 1 s(3)
(1) This time is required for each of the four switched RC filters to fully settle to the new settings. The same time is applicable whenever there is a change to any of the signal chain controls (for example, LED current setting, TIA gain, and so forth).
(2) If the SPI commands involve a change in the TX_REF value from its default, then there is additional wait time of approximately 1 s (for a 2.2-µF decoupling capacitor on the TX_REF pin).
(3) Dependent on the value of the capacitors on the BG and TX_REF pins. The 1-s wait time is necessary when the capacitors are 2.2 µF and scale down proportionate to the capacitor value. A very low capacitor (for example, 0.1 µF) on these pins causes the transmitter dynamic range to reduce to approximately 100 dB.
(4) After an active power-down from AFE_ PDN, the device should be reset using a low-going RESET pulse.
GUID-8E7AE590-B2E6-439B-8415-B4365BD20404-low.gifFigure 7-3 Supply Ramp and Hardware Power-Down Timing
GUID-19D1B5C5-DA12-46D5-B00D-19E7087DBA49-low.gifFigure 7-4 Supply Ramp and Software Power-Down Timing