SNVAA88 December   2023 LM51581-Q1 , TPS1H000-Q1 , TPS92642-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2System Description
    1. 2.1 Dual Cable Concept
    2. 2.2 Single Cable Concept
  6. 3Camera Module Design with Single Coaxial Cable Connection
    1. 3.1 Power-Over-Coax Filter
    2. 3.2 Boost Converter
    3. 3.3 High-Side Switch
    4. 3.4 Buffer Capacitor
    5. 3.5 LED Driver
    6. 3.6 Serializer
    7. 3.7 Design Steps
  7. 4Test Results
    1. 4.1 LED and PoC Voltage Waveforms
    2. 4.2 Margin Analysis Program Result
    3. 4.3 Differential Supply Noise Level
    4. 4.4 Test Cases
  8. 5Summary
  9. 6References

2 System Description

Figure 2-1 shows the basic architecture in the car with the DMS Electronic Control Unit (ECU) and the remote camera module which includes the near-infrared (NIR) illumination.

GUID-20231204-SS0I-3SWJ-JLRX-B4RQHW7QKXF8-low.svg Figure 2-1 DMS Architecture with Remote Camera Module

The ECU module provides power to the camera module and receives the image data from the camera module via a high-speed Serializer/Deserializer (SerDes) link. The NIR illumination is commonly implemented by using cost-effective IR LEDs to maintain robust operation in different driving situations with changing light conditions. Another benefit of using light in the IR spectrum is that the light is invisible to the human eye and cannot distract the driver, but can cause damage to the retina of the eye at higher power and exposure times. The camera module can be positioned in various locations within the car, e.g. in the instrument cluster, dashboard, interior mirror or the a-pillar.

The following two figures illustrate two different concepts how the camera module can be connected to the ECU.