SNOAAA8 April   2025 LM74610-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 What is MLPE
    2. 1.2 Why, When, Where Needs MLPE
    3. 1.3 What is Solar Power Optimizer
    4. 1.4 Solar Power Optimizer Working Principle
    5. 1.5 Output Bypass Function of Solar Power Optimizer
  5. 2Traditional Designs of the Bypass Circuit
    1. 2.1 Design 1 - Using P-N Junction Diode or Schottky Diode
    2. 2.2 Design 2 - Using MOSFET
  6. 3New Design of the Bypass Circuit
    1. 3.1 Requirements on Bypass Circuit
    2. 3.2 Using Ideal Diode Controller LM746x0-Q1
    3. 3.3 Challenges of Using Ideal Diode Controller
    4. 3.4 Working Principle of LM746x0-Q1 Reverse Voltage Range Extension
  7. 4Bench Test and Result
  8. 5Summary
  9. 6References

4 Bench Test and Result

Figure 4-1 shows the LM74610-Q1 Bypass function application schematic with depletion MOSFET and Figure 4-2 shows the demo board top view with test modifications and setup.

LM74610-Q1 Bypass Function Application Schematic With Depletion MOSFETFigure 4-1 LM74610-Q1 Bypass Function Application Schematic With Depletion MOSFET
LM74610-Q1 Bypass Function Demo Board With Depletion MOSFETFigure 4-2 LM74610-Q1 Bypass Function Demo Board With Depletion MOSFET

Figure 4-3 shows test results for a 60V bypass switch design using the 40V LM74610-Q1 controller. With properly scaled MOSFETs (Q1 and QD), the input voltage range can extend to the VDS rating of the FETs. This enables high-voltage designs using the same low-voltage controller. Also, extending the input voltage range can also be useful in enterprise, communication, power tool and high-voltage battery-management applications.

Test Result for a 60V Bypass Circuit with LM74610 and Depletion MOSFET Figure 4-3 Test Result for a 60V Bypass Circuit with LM74610 and Depletion MOSFET
60V bypass LM74610-Q1 with depletion MOSFET
VIN ramped down from 60V to 0V
Device CATHODE pin follows (VIN + VT_QD)
Effective VANODE –VCATHODE clamped to VT of FET QD