TIDUES6 August   2020  – MONTH 

 

  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
    3. 2.3 Highlighted Products
      1. 2.3.1 DRV8906-Q1
      2. 2.3.2 DRV8873-Q1
      3. 2.3.3 TPS1HB16-Q1
      4. 2.3.4 LM2904B-Q1
      5. 2.3.5 TLIN1028-Q1
    4. 2.4 System Design Theory
      1. 2.4.1 Mirror XY and LED Driver
      2. 2.4.2 Mirror Fold Driver
      3. 2.4.3 Mirror Heater Driver for Defogging and De-icing
      4. 2.4.4 Electrochromic Mirror Driver
        1. 2.4.4.1 Sallen-Key Low-Pass Filter
        2. 2.4.4.2 High-Current Buffer Amplifier
        3. 2.4.4.3 Buffer Amplifier Stability for Very-Large Capacitive Loads
        4. 2.4.4.4 Fast Discharge of Large Capacitive Load
      5. 2.4.5 SBC - LIN Communication Interface and System Supply
  8. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Required Hardware and Software
      1. 3.1.1 Hardware
    2. 3.2 Testing and Results
      1. 3.2.1 Test Setup
      2. 3.2.2 Test Results
        1. 3.2.2.1 Reverse Battery Protection
        2. 3.2.2.2 X&Y Motors and LED Driver
        3. 3.2.2.3 Thermal Performance
  9. 4Design Files
    1. 4.1 Schematics
    2. 4.2 Bill of Materials
    3. 4.3 Altium Project
    4. 4.4 Gerber Files
    5. 4.5 Assembly Drawings
  10. 5Software Files
  11. 6Related Documentation
    1. 6.1 Trademarks
    2. 6.2 Third-Party Products Disclaimer
  12. 7Terminology

3.2.2.2 X&Y Motors and LED Driver

The DRV8906-Q1, which drives the two X&Y motors and the LEDs, is tested by measuring the operating current of each of the loads while varying the input voltage from 6 V to 18 V. Additionally, the stall current of the X&Y motors and the amount of time it takes the motors to move the mirror from one end to another is measured.

Table 3-1 shows the current through the turn signal LED for input voltage of 6 V, 12 V, and 18 V. The current through the LED is much smaller at 6 V which is expected. Despite the low current, the LED turns on.

Table 3-1 Current Through Turn Signal LED
INPUT VOLTAGE (V)CURRENT (mA)
61.30
1217.0
1833.3

Table 3-2 and Table 3-3 shows the running current and stalling current of the Y-direction and X-direction motor for 6-V, 12-V, and 18-V input voltage respectively. The table also shows the time it takes for the mirror to travel from one end to another. In both motors, the running current and stall current increases as the supply voltage increases.

Table 3-2 Y-direction Motor Results
INPUT VOLTAGE (V)RUNNING CURRENT (mA)STALL CURRENT (mA)TIME TO REACH END (sec)
628.537.715.8
1233.744.56.45
1837.647.04.10
Table 3-3 X-direction Motor Results
INPUT VOLTAGE (V)RUNNING CURRENT (mA)STALL CURRENT (mA)TIME TO REACH END (sec)
610.510.612.64
1227.537.55.60
1833.244.04.01