SNVAA32 july   2023 LMQ644A2-Q1

 

  1.   1
  2.   LMQ644A2-Q1 6-Phase Buck Regulator Design for Automotive ADAS Applications
  3.   Trademarks
  4. 1 Introduction
    1. 1.1 Features and Electrical Performance
  5. 2Design Specifications
  6. 3Application Circuit Diagram and Operating Configuration Table
  7. 4Top and Bottom Board Views
  8. 5Test Data and Performance Curves
    1. 5.1 Conversion Efficiency
    2. 5.2 Operating Waveforms
      1. 5.2.1 6-phase Switching
      2. 5.2.2 Load Transient Response
      3. 5.2.3 Loop Response
      4. 5.2.4 Startup/Shutdown
    3. 5.3 Thermal Performance
    4. 5.4 CISPR 25 EMI Performance
  9. 6EVM Documentation
    1. 6.1 Schematic
    2. 6.2 Bill of Materials
    3. 6.3 PCB Layout
  10. 74-Phase Configuration
    1. 7.1 4-Phase Switching
  11. 8Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Development Support
    2. 8.2 Documentation Support
      1. 8.2.1 References
        1. 8.2.1.1 PCB Layout Resources
        2. 8.2.1.2 Thermal Design Resources

3 Application Circuit Diagram and Operating Configuration Table

Figure 3-1 shows the typical diagram of 6-phase synchronous buck regulator using LMQ644A2-Q1. SS, COMP and MODE/SYNC of each devices are connected together to share the same information. The SYNC_OUT of primary device is connected to the SYNC of secondary device, and the SYNC_OUT of secondary device is connected to the SYNC of tertiary device to synchronize three devices with phase interleaving.

GUID-20220222-SS0I-6NSV-VX4F-0ZQFZD8LCHJD-low.svg Figure 3-1 LMQ644A2-Q1 6-Phase Synchronous Buck Regulator Diagram
Table 3-1 describes the jumper and input terminal configurations of the LMQ644A2-Q1 6-phase reference design
Table 3-1 Operating Configuration Table
Operating Condition Configuration
3.3 V output J1 #1-#2 short, J7 open
5.0 V output J1 #2-#3 short, J7 open
2.5 V output J1 open, J7 short
Dither Enable J4 #2-#3 short
Dither Disable J4 #1-#2 short
AUTO Mode J2 #1-#2 short
FPWM Mode J2 #2-#3 short
Global Enable J8 #2-#3 short
Global Disable J8 #1-#2 short
EMI Bypass Positive supply input to T3, Negative supply input to T4
EMI Input Disconnect T3 and T4, Connect LISN(+) to VIN_EMI pad on the bottom, Connect LISN(-) to GND pad on the bottom