SNOSDC2B September   2021  – July 2022 LM74721-Q1

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Switching Characteristics
    7. 6.7 Typical Characteristics
  7. 7 Parameter Measurement Information
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Reverse Battery Protection (A, C, GATE)
        1. 8.3.1.1 Input TVS Less Operation: VDS Clamp
      2. 8.3.2 Load Disconnect Switch Control (PD)
      3. 8.3.3 Overvoltage Protection and Battery Voltage Sensing (VSNS, SW, OV)
      4. 8.3.4 Boost Regulator
    4. 8.4 Shutdown Mode
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical 12-V Reverse Battery Protection Application
      1. 9.2.1 Design Requirements for 12-V Battery Protection
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Boost Converter Components (C2, C3, L1)
        2. 9.2.2.2 Input and Output Capacitance
        3. 9.2.2.3 Hold-Up Capacitance
        4. 9.2.2.4 MOSFET Selection: Q1
      3. 9.2.3 Application Curves
    3. 9.3 What to Do and What Not to Do
  10. 10Power Supply Recommendations
    1. 10.1 Transient Protection
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Receiving Notification of Documentation Updates
    2. 12.2 Support Resources
    3. 12.3 Trademarks
    4. 12.4 Electrostatic Discharge Caution
    5. 12.5 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

6.5 Electrical Characteristics

TJ = –40°C to +125°C; typical values at TJ = 25°C, V(A) = V(VS) = 12 V, C(CAP) = 1 µF, V(EN) = 2 V, over operating free-air temperature range (unless otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
VA, V(VS) SUPPLY VOLTAGE
VCLAMP V(C–A) clamp voltage 34.5 43 V
V(A POR) VA POR Rising threshold 3.1 3.4 3.85
VA POR Falling threshold 2.2 2.6 2.9
V(VS)
Minimum Voltage at VS

3 V
VS POR Rising 2.58 2.8 2.95
VS POR Falling  2.35 2.6 2.85
I(SHDN) Shutdown Supply Current V(EN) = 0 V 2 3.3 µA
I(Q) Total System Quiescent Current V(EN) = 2 V, Active Rectifier Controller In Regulation, –40°C ≤ TJ ≤ +85°C 27 32
V(EN) = 2 V, Active Rectifier Controller In Regulation, –40°C ≤ TJ ≤ +125°C 27 35
ENABLE INPUT
V(EN_IH) Enable input high threshold 2 V
V(EN_IL) Enable input low threshold 0.5 0.85 1.2
V(EN_Hys) Enable Hysteresis 485 mV
I(EN) Enable sink current V(EN) = 12 V 55 155 nA
VANODE to VCATHODE
V(AC_REG) Regulated Forward V(AC) Threshold 9 16.4 22.7 mV
V(AC_FWD) V(AC) threshold from RCB to Forward conduction 75 105 140
V(AC_REV) V(AC) threshold for reverse current blocking –12 –5.65 –1.3
GATE DRIVE
V(GATE) - V(A) 3V < V(VS) < 65V 9.5 13 V
I(GATE_Pull down) Peak Pulldown current V(A) – V(C) = –20 mV, 
V(GATE) – V(A) = 100 mV		 2.5 A
I(GATE) Regulation max sink current V(A) – V(C) = 0 V, V(GATE) – V(A) = 5 V  14 26 39 µA
RGATE GATE pulldown resistance V(A) – V(C) = –20 mV, 
V(GATE) – V(A) = 100 mV		 1.2 Ω
BOOST REGULATOR CHARGE PUMP
V(CAP) –  V(c) Boost output rising threshold 13 15.5 V
Hysteresis 1.1
I(CAP) Boost load capacity V(CAP) – V(VS)  = 7.5 V 29 mA
I(LX) Peak inductor current limit threshold V(VS) = 12 V 110 140 170 mA
V(VS) = 3 V 210
R(LX) Low side switch On-Resistance 1.3 2.7 5.1 Ω
BATTERY SENSING (VSNS, SW) AND OVER VOLTAGE DETECTION (OVP, PD)
R(SW) Battery sensing disconnect switch resistance 104 226 430 Ω
V(OVR) Overvoltage threshold input, rising 1.13 1.231 1.33 V
V(OVF) Overvoltage threshold input, falling 1.03 1.125 1.215
V(OV_Hys) OV Hysteresis 110 mV
I(OV) OV Input leakage current 0 V < V(OV) < 5 V 50 110 nA
I(PD_SRC) Pullup current 3V < VS < 65V 43 50 60 µA
I(PD_SINK) Peak Pulldown current V(OV) > V(OVR) 55 88 117 mA
DC Pulldown current 7 10 14
CATHODE
I(C) CATHODE sink current V(A) = 12 V, V(A) – V(C) = –100 mV 9.4 15 µA
V(A) = –14 V, V(C) = 14 V 10.6 18