TIDT386 April   2024

 

  1.   1
  2.   Description
  3.   Features
  4.   Applications
  5. 1Test Prerequisites
    1. 1.1 Voltage and Current Requirements
    2. 1.2 Dimensions
  6. 2Testing and Results
    1. 2.1 Efficiency Graphs
      1. 2.1.1 –7V Output Voltage
      2. 2.1.2 –11V Output Voltage
    2. 2.2 Efficiency Data
    3. 2.3 Thermal Images
      1. 2.3.1 8V Input Voltage
      2. 2.3.2 48V Input Voltage
    4. 2.4 Bode Plots
      1. 2.4.1 8V Input Voltage
        1. 2.4.1.1 –7V Output Voltage
        2. 2.4.1.2 –11V Output Voltage
      2. 2.4.2 48V Input Voltage
        1. 2.4.2.1 –7V Output Voltage
        2. 2.4.2.2 –11V Output Voltage
  7. 3Waveforms
    1. 3.1 Switching
      1. 3.1.1 12V Input Voltage
        1. 3.1.1.1 –7V Output Voltage
          1. 3.1.1.1.1 Switchnode Referenced to –VOUT
          2. 3.1.1.1.2 Switchnode Referenced to VIN
        2. 3.1.1.2 –11V Output Voltage
          1. 3.1.1.2.1 Switchnode Referenced to –VOUT
          2. 3.1.1.2.2 Switchnode Referenced to VIN
      2. 3.1.2 48V Input Voltage
        1. 3.1.2.1 –7V Output Voltage
          1. 3.1.2.1.1 Switchnode Referenced to –VOUT
          2. 3.1.2.1.2 Switchnode Referenced to VIN
        2. 3.1.2.2 –11V Output Voltage
          1. 3.1.2.2.1 Switchnode Referenced to –VOUT
          2. 3.1.2.2.2 Switchnode Referenced to VIN
    2. 3.2 Input Voltage Ripple
      1. 3.2.1 12V Input Voltage
        1. 3.2.1.1 –7V Output Voltage
        2. 3.2.1.2 –11V Output Voltage
      2. 3.2.2 48V Input Voltage
        1. 3.2.2.1 –7V Output Voltage
        2. 3.2.2.2 –11V Output Voltage
    3. 3.3 Output Voltage Ripple
      1. 3.3.1 12V Input Voltage
        1. 3.3.1.1 –7V Output Voltage
        2. 3.3.1.2 –11V Output Voltage
      2. 3.3.2 48V Input Voltage
        1. 3.3.2.1 –7V Output Voltage
        2. 3.3.2.2 –11V Output Voltage
    4. 3.4 Load Transients
      1. 3.4.1 12V Input Voltage
        1. 3.4.1.1 –7V Output Voltage
        2. 3.4.1.2 –11V Output Voltage
      2. 3.4.2 48V Input Voltage
        1. 3.4.2.1 –7V Output Voltage
        2. 3.4.2.2 –11V Output Voltage
    5. 3.5 Level Shifters
    6. 3.6 Start-Up Sequence

Description

This reference design is a flexible and compact power supply providing a negative output voltage rail. The design includes a LM70880-Q1 device (a 80V, 8A high-efficiency buck converter). The output voltage value can be selected among three predefined settings: –7V, –10V, and –11V.