SLVSFH8B
September 2021 – March 2022
LM74720-Q1
PRODUCTION DATA
1
Features
2
Applications
3
Description
4
Revision History
5
Pin Configuration and Functions
6
Specifications
6.1
Absolute Maximum Ratings
6.2
ESD Ratings
6.3
Recommended Operating Conditions
6.4
Thermal Information
6.5
Electrical Characteristics
6.6
Switching Characteristics
6.7
Typical Characteristics
7
Parameter Measurement Information
8
Detailed Description
8.1
Overview
8.2
Functional Block Diagram
8.3
Feature Description
8.3.1
Dual Gate Control (GATE, PD)
8.3.1.1
Reverse Battery Protection (A, C, GATE)
8.3.1.2
Load Disconnect Switch Control (PD)
8.3.2
Overvoltage Protection and Battery Voltage Sensing (VSNS, SW, OV)
8.3.3
Boost Regulator
8.4
Device Functional Mode (Shutdown Mode)
9
Application and Implementation
9.1
Application Information
9.2
Typical 12-V Reverse Battery Protection Application
9.2.1
Design Requirements for 12-V Battery Protection
9.2.2
Automotive Reverse Battery Protection
9.2.2.1
Input Transient Protection: ISO 7637-2 Pulse 1
9.2.2.2
AC Super Imposed Input Rectification: ISO 16750-2 and LV124 E-06
9.2.2.3
Input Micro-Short Protection: LV124 E-10
9.2.3
Detailed Design Procedure
9.2.3.1
Design Considerations
9.2.3.2
Boost Converter Components (C2, C3, L1)
9.2.3.3
Input and Output Capacitance
9.2.3.4
Hold-Up Capacitance
9.2.3.5
Overvoltage Protection and Battery Monitor
9.2.3.6
MOSFET Selection: Blocking MOSFET Q1
9.2.3.7
MOSFET Selection: Load Disconnect MOSFET Q2
9.2.3.8
TVS Selection
9.2.4
Application Curves
9.3
Do's and Don'ts
10
Power Supply Recommendations
10.1
Transient Protection
10.2
TVS Selection for 12-V Battery Systems
10.3
TVS Selection for 24-V Battery Systems
11
Layout
11.1
Layout Guidelines
11.2
Layout Example
12
Device and Documentation Support
12.1
Third-Party Products Disclaimer
12.2
Receiving Notification of Documentation Updates
12.3
Support Resources
12.4
Trademarks
12.5
Electrostatic Discharge Caution
12.6
Glossary
13
Mechanical, Packaging, and Orderable Information
Package Options
Mechanical Data (Package|Pins)
DRR|12
MPSS085A
Thermal pad, mechanical data (Package|Pins)
DRR|12
PPTD367
Orderable Information
slvsfh8b_oa
slvsfh8b_pm
9.2.4
Application Curves
Figure 9-7
Start-up 12 V with EN Pulled to VIN
Figure 9-9
Reverse Input Voltage –14 V for 60 s
Figure 9-11
Inrush Current with 60-Ω Load
Figure 9-13
Output Turn-on with Enable
Figure 9-15
PD Turn-on with Enable
Figure 9-17
Overvoltage Recovery
Figure 9-19
Turn-off Delay – GATE
Figure 9-8
Start-up 12 V Showing Boost Output (V
CAP
) and Switching (V
LX
)
Figure 9-10
Inrush Current with No Load at Output
Figure 9-12
Hot-Plug into 12 V
Figure 9-14
GATE Turn-on with Enable
Figure 9-16
Overvoltage Protection
Figure 9-18
Turn-on Delay – PD
Figure 9-20
Turn-off Delay – PD