SNVS602L March   2009  – June 2016 LM3409 , LM3409-Q1 , LM3409HV , LM3409HV-Q1

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Buck Current Regulators
      2. 8.3.2 Controlled Off-Time (COFT) Architecture
        1. 8.3.2.1 Adjustable Peak Current Control
        2. 8.3.2.2 Controlled Off-Time
      3. 8.3.3 Average LED Current
      4. 8.3.4 Inductor Current Ripple
      5. 8.3.5 Switching Frequency
      6. 8.3.6 PWM Dimming Using the EN Pin
      7. 8.3.7 High Voltage Negative BIAS Regulator
      8. 8.3.8 External Parallel FET PWM Dimming
    4. 8.4 Device Functional Modes
      1. 8.4.1 Low-Power Shutdown
      2. 8.4.2 Thermal Shutdown
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Input Undervoltage Lockout (UVLO)
      2. 9.1.2 Operation Near Dropout
      3. 9.1.3 LED Ripple Current
      4. 9.1.4 Buck Converters without Output Capacitors
      5. 9.1.5 Buck Converters With Output Capacitors
      6. 9.1.6 Output Overvoltage Protection
      7. 9.1.7 Input Capacitors
      8. 9.1.8 P-Channel MOSFET (PFET)
      9. 9.1.9 Re-Circulating Diode
    2. 9.2 Typical Applications
      1. 9.2.1 EN PIN PWM Dimming Application for 10 LEDs
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1  Nominal Switching Frequency
          2. 9.2.1.2.2  Inductor Ripple Current
          3. 9.2.1.2.3  Average LED Current
          4. 9.2.1.2.4  Output Capacitance
          5. 9.2.1.2.5  Input Capacitance
          6. 9.2.1.2.6  PFET
          7. 9.2.1.2.7  Diode
          8. 9.2.1.2.8  Input UVLO
          9. 9.2.1.2.9  IADJ Connection Method
          10. 9.2.1.2.10 PWM Dimming Method
        3. 9.2.1.3 Application Curve
      2. 9.2.2 Analog Dimming Application for 4 LEDs
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
          1. 9.2.2.2.1  Nominal Switching Frequency
          2. 9.2.2.2.2  Inductor Ripple Current
          3. 9.2.2.2.3  Average LED Current
          4. 9.2.2.2.4  Output Capacitance
          5. 9.2.2.2.5  Input Capacitance
          6. 9.2.2.2.6  PFET
          7. 9.2.2.2.7  Diode
          8. 9.2.2.2.8  Input UVLO
          9. 9.2.2.2.9  IADJ Connection Method
          10. 9.2.2.2.10 PWM Dimming Method
        3. 9.2.2.3 Application Curve
      3. 9.2.3 LM3409 Buck Converter Application
        1. 9.2.3.1 Design Requirements
        2. 9.2.3.2 Detailed Design Procedure
          1. 9.2.3.2.1  Nominal Switching Frequency
          2. 9.2.3.2.2  Inductor Ripple Current
          3. 9.2.3.2.3  Average LED Current
          4. 9.2.3.2.4  Output Capacitance
          5. 9.2.3.2.5  Input Capacitance
          6. 9.2.3.2.6  PFET
          7. 9.2.3.2.7  Diode
          8. 9.2.3.2.8  Input UVLO
          9. 9.2.3.2.9  IADJ Connection Method
          10. 9.2.3.2.10 PWM Dimming Method
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Related Links
    3. 12.3 Community Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

7 Specifications

7.1 Absolute Maximum Ratings

over operating free-air temperature range (unless otherwise noted)(1)(2)
MIN MAX UNIT
VIN, EN, UVLO to GND LM3409, LM3409-Q1 –0.3 45 V
LM3409HV, LM3409HV-Q1 –0.3 76
VIN to VCC, PGATE –0.3 7 V
VIN to PGATE for 100 ns –2.8 9.5 V
VIN to CSP, CSN –0.3 0.3 V
COFF to GND –0.3 4 V
COFF Current continuous ±1 mA
IADJ Current continuous ±5 mA
Junction temperature 150 °C
Soldering information Lead temperature (Soldering, 10 s) 260 °C
Infrared and convection reflow (15 s) 260 °C
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.
(2) If Military/Aerospace specified devices are required, contact the Texas Instruments Sales Office/Distributors for availability and specifications.

7.2 ESD Ratings

VALUE UNIT
LM3409 IN DGQ AND NFF PACKAGES
V(ESD) Electrostatic discharge Human body model (HBM), per ANSI/ESDA/JEDEC JS-001, all pins(1) ±1000 V
Charged device model (CDM), per JEDEC specification JESD22-C101, all pins(2) ±1000
LM3409-Q1 IN DGQ AND NFF PACKAGES
V(ESD) Electrostatic discharge Human body model (HBM), per AEC Q100-002(3)(4) ±2000 V
Charged device model (CDM), per AEC Q100-011 ±1000
(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.
(3) AEC Q100-002 indicates HBM stressing is done in accordance with the ANSI/ESDA/JEDEC JS-001 specification.
(4) The human body model is a 100 pF capacitor discharged through a 1.5-kΩ resistor into each pin.

7.3 Recommended Operating Conditions

over operating free-air temperature range (unless otherwise noted)
MIN MAX UNIT
VIN LM3409, LM3409-Q1 6 42 V
LM3409HV, LM3409HV-Q1 6 75
Junction temperature range, TJ −40 125 °C

7.4 Thermal Information

THERMAL METRIC(1) LM3409,
LM3409-Q1,
LM3409HV,
LM3409HV-Q1		 LM3409 UNIT
DGQ
(HVSSOP)		 NFF
(PDIP)
10 PINS 14 PINS
RθJA Junction-to-ambient thermal resistance 54.4 49 °C/W
RθJC(top) Junction-to-case (top) thermal resistance 53.7 36.3 °C/W
RθJB Junction-to-board thermal resistance 33.8 28.9 °C/W
ψJT Junction-to-top characterization parameter 3.9 21.1 °C/W
ψJB Junction-to-board characterization parameter 33.5 28.7 °C/W
RθJC(bot) Junction-to-case (bottom) thermal resistance 3.5 N/A °C/W
(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report, SPRA953.

7.5 Electrical Characteristics

VIN = 24 V unless otherwise indicated. Typicals and limits appearing in plain type apply for TA = TJ = 25°C (2). Data sheet minimum and maximum specification limits are specified by design, test, or statistical analysis.
PARAMETER TEST CONDITIONS MIN(1) TYP(2) MAX(1) UNIT
PEAK CURRENT COMPARATOR
VCST VCSP – VCSN average peak current threshold(3) VADJ = 1 V 188 198 208 mV
VADJ = VADJ-OC 231 246 261
AADJ VADJ to VCSP – VCSN threshold gain 0.1 < VADJ < 1.2 V
VADJ = VADJ-OC		 0.2 V/V
VADJ-OC IADJ pin open circuit voltage 1.189 1.243 1.297 V
IADJ IADJ pin current 3.8 5 6.4 µA
tDEL CSN pin falling delay CSN fall - PGATE rise 38 ns
SYSTEM CURRENTS
IIN Operating input current Not switching 2 mA
ISD Shutdown input current EN = 0 V 110 µA
PFET DRIVER
RPGATE Driver output resistance Sourcing 50 mA 2 Ω
Sinking 50 mA 2
VCC REGULATOR
VCC VIN pin voltage - VCC pin voltage VIN > 9 V
0 < ICC < 20 mA		 5.5 6 6.5 V
VCC-UVLO VCC undervoltage lockout threshold VCC increasing 3.73 V
VCC-HYS VCC UVLO hysteresis VCC decreasing 283 mV
ICC-LIM VCC regulator current limit 30 45 mA
OFF-TIMER AND ON-TIMER
VOFT Off-time threshold 1.122 1.243 1.364 V
tD-OFF COFF threshold to PGATE falling delay 25 ns
tON-MIN Minimum ON-time 115 211 ns
tOFF-MAX Maximum OFF-time 300 µs
UNDERVOLTAGE LOCKOUT
IUVLO UVLO pin current VUVLO = 1 V 10 nA
VUVLO-R Rising UVLO threshold 1.175 1.243 1.311 V
IUVLO-HYS UVLO hysteresis current 22 µA
ENABLE
IEN EN pin current 10 nA
VEN-TH EN pin threshold VEN rising 1.74 V
VEN falling .5
VEN-HYS EN pin hysteresis 420 mV
tEN-R EN pin rising delay EN rise - PGATE fall 42 ns
tEN-F EN pin falling delay EN fall - PGATE rise 21 ns
(1) Minimum and maximum limits are 100% production tested at 25°C. Limits over the operating temperature range are specified through correlation using Statistical Quality Control (SQC) methods. Limits are used to calculate Texas Instrument's Average Outgoing Quality Level (AOQL).
(2) Typical values represent most likely parametric norms at the conditions specified and are not ensured.
(3) The current sense threshold limits are calculated by averaging the results from the two polarities of the high-side differential amplifier.

7.6 Typical Characteristics

TA = 25 °C, VIN = 24 V, and characteristics are identical for LM3409 and LM3409HV unless otherwise specified.
LM3409 LM3409-Q1 LM3409HV LM3409HV-Q1 300856b5.gif Figure 1. VCST vs Junction Temperature
LM3409 LM3409-Q1 LM3409HV LM3409HV-Q1 300856b8.gif Figure 3. VADJ vs Junction Temperature
LM3409 LM3409-Q1 LM3409HV LM3409HV-Q1 300856b9.gif Figure 5. VOFT vs Junction Temperature
LM3409 LM3409-Q1 LM3409HV LM3409HV-Q1 300856f0.gif Figure 7. LM3409 Efficiency vs Input Voltage VO = 17 V (5 LEDs); ILED = 2 A
LM3409 LM3409-Q1 LM3409HV LM3409HV-Q1 300856f1.gif Figure 9. LM3409 LED Current vs Input Voltage VO = 17 V (5 LEDs)
LM3409 LM3409-Q1 LM3409HV LM3409HV-Q1 300856c1.gif Figure 11. Normalized Switching Frequency vs Input Voltage
LM3409 LM3409-Q1 LM3409HV LM3409HV-Q1 300856b0.gif Figure 13. Internal EN Pin PWM Dimming VO = 17 V (5 LEDs); VIN = 24 V
LM3409 LM3409-Q1 LM3409HV LM3409HV-Q1 300856f5.gif
NOTE: The waveforms were acquired using the standard evaluation board from AN-1953 (SNVA390).
Figure 15. 20 kHz 50% EN Pin PWM Dimming VO = 42 V (12 LEDs); VIN = 48 V
LM3409 LM3409-Q1 LM3409HV LM3409HV-Q1 300856f7.gif
NOTE: The waveforms were acquired using the standard evaluation board from AN-1953 (SNVA390).
Figure 17. 20 kHz 50% EN Pin PWM Dimming (Rising Edge) VO = 42 V (12 LEDs); VIN = 48 V
LM3409 LM3409-Q1 LM3409HV LM3409HV-Q1 300856b6.gif Figure 2. VCC vs Junction Temperature
LM3409 LM3409-Q1 LM3409HV LM3409HV-Q1 300856b7.gif Figure 4. IADJ vs Junction Temperature
LM3409 LM3409-Q1 LM3409HV LM3409HV-Q1 300856c0.gif Figure 6. tON-MIN vs Junction Temperature
LM3409 LM3409-Q1 LM3409HV LM3409HV-Q1 300856b3.gif Figure 8. LM3409HV Efficiency vs Input Voltage VO = 17 V (5 LEDs); ILED = 2 A
LM3409 LM3409-Q1 LM3409HV LM3409HV-Q1 300856b4.gif Figure 10. LM3409HV LED Current vs Input Voltage VO = 17 V (5 LEDs)
LM3409 LM3409-Q1 LM3409HV LM3409HV-Q1 300856b2.gif Figure 12. Amplitude Dimming Using IADJ Pin VO = 17 V (5 LEDs); VIN = 24 V
LM3409 LM3409-Q1 LM3409HV LM3409HV-Q1 300856b1.gif Figure 14. External Parallel FET PWM Dimming VO = 17 V (5 LEDs); VIN = 24 V
LM3409 LM3409-Q1 LM3409HV LM3409HV-Q1 300856f6.gif
NOTE: The waveforms were acquired using the standard evaluation board from AN-1953 (SNVA390).
Figure 16. 100 kHz 50% External FET PWM Dimming VO = 42 V (12 LEDs); VIN = 48 V
LM3409 LM3409-Q1 LM3409HV LM3409HV-Q1 300856f8.gif
The waveforms were acquired using the standard evaluation board from AN-1953 (SNVA390).
Figure 18. 100 kHz 50% External FET PWM Dimming (Rising Edge) VO = 42 V (12 LEDs); VIN = 48 V