SNVS553C January   2008  – November 2016 LM3407

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 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Floating Buck Switching Converter
      2. 7.3.2 Pulse Level Modulation (PLM)
      3. 7.3.3 Internal VCC Regulator
      4. 7.3.4 Clock Generator
      5. 7.3.5 PWM Dimming of LED String
      6. 7.3.6 Input Under-Voltage Lock-Out (UVLO)
    4. 7.4 Device Functional Modes
      1. 7.4.1 Low-Power Shutdown Mode
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Switching Frequency Selection
      2. 8.1.2 LED Current Setting
      3. 8.1.3 Input and Output Capacitors
      4. 8.1.4 Selection of Inductor
      5. 8.1.5 Free-Wheeling Diode
    2. 8.2 Typical Applications
      1. 8.2.1 LM3407 Design Example
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Calculate RISNS
          2. 8.2.1.2.2 Calculate RFS
          3. 8.2.1.2.3 Choose L
          4. 8.2.1.2.4 Choose CIN and CVCC
        3. 8.2.1.3 Application Curve
      2. 8.2.2 Typical Application for Driving 6 LEDs
      3. 8.2.3 Typical Application for Driving 1 LED
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

6 Specifications

6.1 Absolute Maximum Ratings

over operating free-air temperature range (unless otherwise noted)(1)
MIN MAX UNIT
VIN to GND –0.3 36 V
VIN to GND (transient) 42 (500 ms) V
LX to GND –0.3 36 V
LX to GND (transient) –3 (2 ns) 42 (500 ms) V
FS, ISNS, DIM, EN to GND –0.3 7 V
Storage temperature, Tstg –65 125 °C
(1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

6.2 ESD Ratings

VALUE UNIT
V(ESD) Electrostatic discharge Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001(1) ±2000 V
Charged-device model (CDM), per JEDEC specification JESD22-C101(2) ±750
(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
(2) JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.

6.3 Recommended Operating Conditions

over operating free-air temperature range (unless otherwise noted)
MIN MAX UNIT
VIN 4.5 30 V
Junction temperature –40 125 °C

6.4 Thermal Information

THERMAL METRIC(1) LM3407 UNIT
DGN (MSOP)
8 PINS
RθJA Junction-to-ambient thermal resistance 55.6 °C/W
RθJC(top) Junction-to-case (top) thermal resistance 50.7 °C/W
RθJB Junction-to-board thermal resistance 28.8 °C/W
ψJT Junction-to-top characterization parameter 1.6 °C/W
ψJB Junction-to-board characterization parameter 28.6 °C/W
RθJC(bot) Junction-to-case (bottom) thermal resistance 4.9 °C/W
(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report.

6.5 Electrical Characteristics

MIN and MAX limits apply for TJ = –40°C to +125°C unless specified otherwise. VIN = 12 V unless otherwise indicated.
PARAMETER TEST CONDITIONS MIN(1) TYP(2) MAX(1) UNIT
SYSTEM PARAMETERS
IIN Operating input current 4.5 V ≤ VIN ≤ 30 V, LX = open,
VPWM = VEN = 5 V		 0.58 0.78 0.98 mA
IQ Quiescent Input current 4.5 V ≤ VIN ≤ 30 V,
VPWM = 0 V, VEN = 5 V		 0.2 0.27 0.39 mA
ISHUT Shutdown input current VEN = 0 V 36 48 60 µA
VUVLO Input undervoltage lockout threshold VIN Rising 3.6 4.5 V
VUVLO-HYS UVLO hysteresis VIN Falling 200 mV
VEN_H EN Pin HIGH threshold VEN Rising 1.9 2.4 V
VEN_L EN Pin LOW threshold VEN Falling 1.3 1.75 V
VDIM_H DIM Pin HIGH threshold VDIM Rising 1.9 2.4 V
VDIM_L DIM Pin LOW threshold VDIM Falling 1.3 1.75 V
fSW Switching frequency RT = 80 kΩ 500 kHz
RT = 40 kΩ 1000
tON-MIN Minimum on-time 200 ns
TSD Thermal shutdown threshold 165 °C
TSD-HYS Thermal shutdown hysteresis 25
INTERNAL VOLTAGE REGULATOR
VCC VCC regulator output voltage(3) VIN = 12 V 4.5 V
MAIN SWITCH
RDS(ON) Main switch ON resistance ISINK = 80 mA 0.77 1.45 Ω
CONTROL LOOP
AEA Error amp open loop gain 60 dB
(1) All limits specified at room temperature (TYP) and at temperature extremes (MIN/MAX). All room temperature limits are 100% production tested. All limits at temperature extremes are specified through correlation using standard Statistical Quality Control (SQC) methods. All limits are used to calculate Average Outgoing Quality Level (AOQL).
(2) Typical specification represent the most likely parametric norm at 25°C operation.
(3) VCC provides self bias for the internal gate drive and control circuits. Device thermal limitations limit external loading to the pin.

6.6 Typical Characteristics

All curves taken at VIN = 12 V with configuration in typical application for driving two power LEDs with ILED = 0.35 A shown in this data sheet and TA = 25°C, unless otherwise specified.
LM3407 30046603.png
TA = -40°C
Figure 1. Output Current vs Input Voltage
LM3407 30046633.png
TA = 125°C
Figure 3. Output Current vs Input Voltage
LM3407 30046605.png
TA = 25°C
Figure 5. Efficiency vs Input Voltage
LM3407 30046607.png
Figure 7. Switch On Time vs Input Voltage
LM3407 30046609.png
Figure 9. VCC Voltage vs Input Voltage
LM3407 30046611.png Figure 11. Switching Frequency vs RFS
LM3407 30046613.png
VIN = 12 V L = 33 µH fSW = 500 kHz
Figure 13. Continuous Mode Operation
LM3407 30046615.png
VIN = 24 V L = 33 µH fSW = 500 kHz
Figure 15. Continuous Mode Operation
LM3407 30046617.png
VIN = 12 V L = 33 µH fSW = 1 MHz
Figure 17. DIM Pin Disable Transient
LM3407 30046632.png
TA = 25°C
Figure 2. Output Current vs Input Voltage
LM3407 30046604.png
TA = -40°C
Figure 4. Efficiency vs Input Voltage
LM3407 30046606.png
TA = 125°C
Figure 6. Efficiency vs Input Voltage
LM3407 30046608.png
Figure 8. Operating Input Current vs Input Voltage
LM3407 30046610.png
Figure 10. Output Current vs RISNS
LM3407 30046612.png
VIN = 12 V L = 33 µH fSW = 1 MHz
Figure 12. Continuous Mode Operation
LM3407 30046614.png
VIN = 24 V L = 33 µH fSW = 1 MHz
Figure 14. Continuous Mode Operation
LM3407 30046616.png
VIN = 12 V L = 33 µH fSW = 1 MHz
Figure 16. DIM Pin Enable Transient