SNOAA94 june   2023 LM74900-Q1 , LM74910-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1 LM749x0-Q1 Ideal Diode Controller Overview
  5. 2 Design 1: Automotive Reverse Battery Protection with Overvoltage, Undervoltage and Overcurrent Protection with Fault Output
  6. 3 Design 2: LM749x0-Q1 as Ideal Diode Controller with Current Monitoring, Overcurrent and Undervoltage Fault Indication
  7. 4 Design 3: LM749x0-Q1 as High Side Driver with Undervoltage, Overvoltage and Overcurrent Protection
  8. 5 Feature Comparison: LM749x0-Q1 as Ideal Diode FET and High Side Driver Topology
  9. 6 Design 4: Dual Supply OR-ing with Common Powerpath Disconnect Function
  10. 7 Design 5: LM749x0-Q1 as Priority Power MUX Controller
  11. 8 Feature Comparison: Dual OR-ing and Priority Power MUX Controller Topologies
  12. 9 Summary
  13. 10References

4 Design 3: LM749x0-Q1 as High Side Driver with Undervoltage, Overvoltage and Overcurrent Protection

In automotive load driving applications, N-Channel MOSFET based high side switch is very commonly used to disconnect the loads from supply line in case of faults such as overvoltage, overcurrent event . LM749x0-Q1 can be used to drive external MOSFET to realize simple high side switch with fault protection. Figure 4-1 shows a typical application circuit where LM749x0-Q1 is used to drive external MOSFET Q2 as a main power path connect and disconnect switch. The pin configuration to set threshold for overvoltage (OV), overcurrent with circuit breaker (ILIM, TMR), Short-circuit (ISCP) and undervoltage is described in detail in device feature description.

GUID-20230523-SS0I-ZFZL-SVMJ-FTHVBWQLCD29-low.svgFigure 4-1 Typical Application Circuit for LM749x0-Q1 as High Side Driver

LM749x0-Q1 when used to drive only high side FET, DGATE needs to be left floating while A, C can be shorted together.

When used as high side switch controller to drive external MOSFET, device is capable of operating in SLEEP mode (SLEEP = 0, EN = 1) ensuring ultra-low power consumption (5-μA typical) while providing load current to always on loads through internal bypass switch with on resistance of 10Ω. In SLEEP mode device is capable of providing overcurrent (250-mA typical) and overvoltage (21-V typical threshold) protection.

GUID-20230523-SS0I-XTNC-BFKQ-VL1B9M46M9HN-low.svgFigure 4-2 LM749x0-Q1 SLEEP Mode