SNVU770 June   2021 LM5157 , LM5157-Q1 , LM51571-Q1

 

  1.   Trademarks
  2. 1Introduction
  3. 2Electrical Parameters
  4. 3Application Schematic
  5. 4EVM Picture
  6. 5Test Setup and Procedure
    1. 5.1 EVM Test Setup Schematic
    2. 5.2 Test Equipment
  7. 6Test Data and Performance Curves
    1. 6.1 Efficiency
    2. 6.2 Output Regulation and Cross-Regulations
    3. 6.3 Steady-State Waveforms
    4. 6.4 Start-Up Waveforms
    5. 6.5 Dynamic Responses
    6. 6.6 Short-Circuit Protection
    7. 6.7 Bode Plots
    8. 6.8 Thermal Image
  8. 7Schematic
  9. 8Bill of Materials
  10. 9EVM Layout

2 Electrical Parameters

Table 2-1 details the electrical performance standard configuration.

Table 2-1 Electrical Performance Standard Configuration
Parameter Test Conditions MIN TYP MAX Unit
Input Characteristics
Input voltage range VIN Operation 8 12 16 V
Abs max input voltage VINMAX Operation without damage 18 V
Input voltage turn-on VIN(ON) Adjustable by the UVLO/SYNC resistors 7.5 V
Input voltage turn-on VIN(OFF) 7.3 V
Output Characteristics
Main output voltage Vo1 10 V
1st Isolated output voltage Vo2 20 V
2nd Isolated output voltage Vo3 20 V
3rd Isolated output voltage Vo4 20 V
Main output load current Io1 0.250 A
1st Isolated output load current Io2 0.075 A
2nd Isolated output load current Io3 0.075 A
3rd Isolated output load current Io4 0.150 A
System Characteristics
Switching Frequency 250 kHz
Peak Efficiency VIN = 12 V, rated load at all output rails 91 %
Junction Temperature –40 150 °C
Transformer Specifications (Coilcraft ZB1324-AL)
Primary Inductances 8 µH
Turns Ratio (2-4) : (1-3) 1
(5-6) : (1-3) 1.2
(8-7) : (1-3) 2.4
(10-9) : (1-3) 2.4
(12-11) : (1-3) 2.4
Saturation Current 20% inductance reduction 5.5 A
Leakage Inductance 90 nH