TIDUF06 August   2022

 

  1.   Description
  2.   Resources
  3.   Features
  4.   Applications
  5.   5
  6. 1System Description
    1. 1.1 Key System Specifications
  7. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
      1. 2.2.1 PCB and Form Factor
      2. 2.2.2 Power Supply Design
        1. 2.2.2.1 POC Filter
        2. 2.2.2.2 Power Supply Considerations
          1. 2.2.2.2.1 Choosing External Components
          2. 2.2.2.2.2 Choosing the Buck 1 Inductor
          3. 2.2.2.2.3 Choosing the Buck 2 and Buck 3 Inductors
          4. 2.2.2.2.4 Functional Safety
    3. 2.3 Highlighted Products
      1. 2.3.1 DS90UB953-Q1
      2. 2.3.2 TPS650330-Q1
      3. 2.3.3 IMX623
    4. 2.4 System Design Theory
  8. 3Hardware, Testing Requirements, and Test Results
    1. 3.1 Required Hardware
      1. 3.1.1 Hardware Setup
      2. 3.1.2 FPD-Link III I2C Initialization
      3. 3.1.3 IMX623 Initialization
    2. 3.2 Testing and Results
      1. 3.2.1 Test Setup
        1. 3.2.1.1 Power Supplies Startup
        2. 3.2.1.2 Power Supply Startup – 1.8 V Rail and Serializer PDB Setup
      2. 3.2.2 Test Results
        1. 3.2.2.1 Power Supplies Start Up
        2. 3.2.2.2 Power Supply Output Voltage Ripple
        3. 3.2.2.3 Power Supply Load Currents
        4. 3.2.2.4 I2C Communications
  9. 4Design Files
    1. 4.1 Schematics
    2. 4.2 Bill of Materials
    3. 4.3 PCB Layout Recommendations
      1. 4.3.1 PMIC Layout Recommendations
      2. 4.3.2 PCB Layer Stackup
      3. 4.3.3 Serializer Layout Recommendations
      4. 4.3.4 Imager Layout Recommendations
      5. 4.3.5 Layout Prints
    4. 4.4 Altium Project
    5. 4.5 Gerber Files
    6. 4.6 Assembly Drawings
  10. 5Related Documentation
  11. 6Trademarks

3.2.2.2 Power Supply Output Voltage Ripple

To achieve a quality output video stream, the output voltage ripple on the IMX623 and DS90UB953-Q1 supplies must be low so that it does not affect the integrity of the high-speed CSI-2 data and internal PLL clocks. Figure 3-5 to Figure 3-8 show the measurements for 3.8-V, 1.8-V, 1.1-V, and 3.3-V rails while the camera is streaming video. The measured peak-to-peak ripple voltages are 0.4%, 0.6%, 0.6%, and 0.1% respectively. The tight voltage accuracy allows for the video output to be successfully transmitted.

GUID-20220615-SS0I-JPL7-PJ7K-1PTND4F3D6RV-low.pngFigure 3-5 Output Voltage Ripple: 3.8 V
GUID-20220615-SS0I-BSGN-CF1T-NHMK6J1PGL9F-low.pngFigure 3-7 Output Voltage Ripple: 1.1 V
GUID-20220615-SS0I-QZVC-2MN4-BT1HZRXFZNZ3-low.pngFigure 3-6 Output Voltage Ripple: 1.8 V
GUID-20220615-SS0I-NWSW-LJJ0-DLWGRBRLF19D-low.pngFigure 3-8 Output Voltage Ripple: 3.3 V