SNVS616H April   2009  – July 2015 LM3429 , LM3429-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 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  Current Regulators
      2. 7.3.2  Predictive Off-Time (PRO) Control
      3. 7.3.3  Switching Frequency
      4. 7.3.4  Average LED Current
      5. 7.3.5  Analog Dimming
      6. 7.3.6  Current Sense and Current Limit
      7. 7.3.7  Control Loop Compensation
      8. 7.3.8  Output Overvoltage Lockout (OVLO)
      9. 7.3.9  Input Undervoltage Lockout (UVLO)
      10. 7.3.10 PWM Dimming
      11. 7.3.11 Startup Regulator (VCC LDO)
      12. 7.3.12 Thermal Shutdown
    4. 7.4 Device Functional Modes
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Inductor
      2. 8.1.2 LED Dynamic Resistance (rD)
      3. 8.1.3 Output Capacitor
      4. 8.1.4 Input Capacitors
      5. 8.1.5 N-Channel MosFET (NFET)
      6. 8.1.6 Re-Circulating Diode
    2. 8.2 Typical Applications
      1. 8.2.1 Basic Topology Schematics
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1  Operating Point
          2. 8.2.1.2.2  Switching Frequency
          3. 8.2.1.2.3  Average LED Current
          4. 8.2.1.2.4  Inductor Ripple Current
          5. 8.2.1.2.5  LED Ripple Current
          6. 8.2.1.2.6  Peak Current Limit
          7. 8.2.1.2.7  Loop Compensation
          8. 8.2.1.2.8  Input Capacitance
          9. 8.2.1.2.9  NFET
          10. 8.2.1.2.10 Diode
          11. 8.2.1.2.11 Output OVLO
          12. 8.2.1.2.12 Input UVLO
          13. 8.2.1.2.13 PWM Dimming Method
          14. 8.2.1.2.14 Analog Dimming Method
      2. 8.2.2 Buck-Boost Application - 6 LEDs at 1 A
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
          1. 8.2.2.2.1  Operating Point
          2. 8.2.2.2.2  Switching Frequency
          3. 8.2.2.2.3  Average LED Current
          4. 8.2.2.2.4  Inductor Ripple Current
          5. 8.2.2.2.5  Output Capacitance
          6. 8.2.2.2.6  Peak Current Limit
          7. 8.2.2.2.7  Loop Compensation
          8. 8.2.2.2.8  Input Capacitance
          9. 8.2.2.2.9  NFET
          10. 8.2.2.2.10 Diode
          11. 8.2.2.2.11 Input UVLO
          12. 8.2.2.2.12 Output OVLO
        3. 8.2.2.3 Application Curve
      3. 8.2.3 Boost PWM Dimming Application - 9 LEDs at 1 A
        1. 8.2.3.1 Detailed Design Procedure
      4. 8.2.4 Buck-Boost Analog Dimming Application - 4 LEDs at 2A
        1. 8.2.4.1 Detailed Design Procedure
      5. 8.2.5 Boost Analog Dimming Application - 12 LEDs at 700 mA
        1. 8.2.5.1 Detailed Design Procedure
      6. 8.2.6 Buck-Boost PWM Dimming Application - 6 LEDs at 500 mA
        1. 8.2.6.1 Detailed Design Procedure
      7. 8.2.7 Buck Application - 3 LEDS at 1.25 A
        1. 8.2.7.1 Detailed Design Procedure
      8. 8.2.8 Buck-Boost Thermal Foldback Application - 8 LEDs at 2.5 A
        1. 8.2.8.1 Detailed Design Procedure
      9. 8.2.9 SEPIC Application - 5 LEDs at 750 mA
        1. 8.2.9.1 Detailed Design Procedure
  9. 9 Power Supply Recommendations
    1. 9.1 Input Supply Current Limit
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Related Links
    4. 11.4 Community Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

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6 Specifications

6.1 Absolute Maximum Ratings

over operating free-air temperature range (unless otherwise noted)(1)(2)
MIN MAX UNIT
Voltage VIN, nDIM –0.3 76 V
OVP, HSP, HSN –0.3 76
RCT –0.3 3
IS –0.3 76
–2 for 100 ns
VCC –0.3 8
COMP, CSH –0.3 6
GATE –0.3 VCC
–2.5 for 100 ns VCC+2.5 for 100 ns
PGND –0.3 0.3
–2.5 2.5 for 100 ns
Continuous Current VIN, nDIM –1 mA
OVP, HSP, HSN –100 µA
RCT –1 5 mA
IS –1
COMP, CSH –200 200 µA
GATE –1 1 mA
Maximum Junction Temperature Internally Limited
Maximum Lead Temperature (Reflow and Solder) (3) 260 °C
Continuous Power Dissipation Internally Limited
Storage Temperature, Tstg –65 150 °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.
(3) Refer to http://www.ti.com/packaging for more detailed information and mounting techniques.

6.2 ESD Ratings

VALUE UNIT
LM3429 IN PWP PACKAGE
V(ESD) Electrostatic discharge Human body model (HBM), per ANSI/ESDA/JEDEC JS-001, all pins(1) ±2000 V
Charged device model (CDM), per JEDEC specification JESD22-C101, all pins(2) ±1000
LM3429-Q1 IN PWP PACKAGE
V(ESD) Electrostatic discharge Human body model (HBM), per AEC Q100-002(3) ±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.

6.3 Recommended Operating Conditions

MIN MAX UNIT
Operating Junction Temperature Range –40 125 °C
Input Voltage VIN 4.5 75 V

6.4 Thermal Information

THERMAL METRIC(1) LM3429-Q1 LM3429 UNIT
PWP (HTSSOP) PWP (HTSSOP)
14 PINS 14 PINS
RθJA Junction-to-ambient thermal resistance 47.8 47.8 °C/W
RθJC(top) Junction-to-case (top) thermal resistance 26.5 26.5 °C/W
RθJB Junction-to-board thermal resistance 22.3 22.3 °C/W
ψJT Junction-to-top characterization parameter 0.7 0.7 °C/W
ψJB Junction-to-board characterization parameter 22.1 22.1 °C/W
RθJC(bot) Junction-to-case (bottom) thermal resistance 3.3 3.3 °C/W
(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report, SPRA953.

6.5 Electrical Characteristics

MIN and MAX limits apply TJ = (−40°C to 125°C) unless specified otherwise. Unless otherwise stated the following condition applies: VIN = 14 V.
PARAMETER TEST CONDITIONS MIN(1) TYP(2) MAX(1) UNIT
STARTUP REGULATOR (VCC)
VCC-REG VCC Regulation ICC = 0 mA 6.3 6.9 7.35 V
ICC-LIM VCC Current Limit VCC = 0V 20 27 mA
IQ Quiescent Current Static 1.6 3
VCC-UVLO VCC UVLO Threshold VCC Increasing 4.17 4.5 V
VCC Decreasing 3.7 4.08
VCC-HYS VCC UVLO Hysteresis 0.1
OVERVOLTAGE PROTECTION (OVP)
VTH-OVP OVP OVLO Threshold OVP Increasing 1.18 1.24 1.28 V
IHYS-OVP OVP Hysteresis Source Current OVP Active (high) 10 20 30 µA
ERROR AMPLIFIER
VCSH CSH Reference Voltage With Respect to AGND 1.21 1.235 1.26 V
Error Amplifier Input Bias Current MIN, MAX: TJ = 25°C –0.6 0 0.6 µA
COMP Sink / Source Current 10 26 40
Transconductance 100 µA/V
Linear Input Range  (3) ±125 mV
Transconductance Bandwidth -6dB Unloaded Response(3), MIN: TJ = 25°C 0.5 1 MHz
OFF TIMER (RCT)
tOFF-MIN Minimum Off-time RCT = 1V through 1 kΩ 35 75 ns
RRCT RCT Reset Pulldown Resistance 36 120 Ω
VRCT VIN/25 Reference Voltage VIN = 14V 540 565 585 mV
PWM COMPARATOR
COMP to PWM Offset 700 800 900 mV
CURRENT LIMIT (IS)
VLIM Current Limit Threshold 215 245 275 mV
VLIM Delay to Output 35 75 ns
tON-MIN Leading Edge Blanking Time 75 250 450
HIGH SIDE TRANSCONDUCTANCE AMPLIFIER
Input Bias Current 10 µA
Transconductance 20 119 mA/V
Input Offset Current –1.5 0 1.5 µA
Input Offset Voltage –7 0 7 mV
Transconductance Bandwidth ICSH = 100 µA(3), MIN: TJ = 25°C 250 500 kHz
GATE DRIVER (GATE)
RSRC(GATE) GATE Sourcing Resistance GATE = High 2 6 Ω
RSNK(GATE) GATE Sinking Resistance GATE = Low 1.3 4.5
UNDERVOLTAGE LOCKOUT and DIM INPUT (nDIM)
VTH-nDIM nDIM / UVLO Threshold 1.18 1.24 1.28 V
IHYS-nDIM nDIM Hysteresis Current 10 20 30 µA
THERMAL SHUTDOWN
TSD Thermal Shutdown Threshold  (3) 165 °C
THYS Thermal Shutdown Hysteresis  (3) 25
(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 numbers are at 25°C and represent the most likely norm.
(3) These electrical parameters are specified by design, and are not verified by test.

6.6 Typical Characteristics

TA= 25°C and VIN = 14 V unless otherwise specified. The measurements for Figure 1 and Figure 3 were made using the standard boost evaluation board from AN-1986 (SNVA404). The measurements for Figure 2, Figure 4, and Figure 5, Figure 6 were made using the standard buck-boost evaluation board from AN-1985 (SNVA403).
LM3429 LM3429-Q1 300944b6.gif
Figure 1. Boost Efficiency vs Input Voltage
VO = 32 V (9 LEDs)
LM3429 LM3429-Q1 300944b8.gif
Figure 3. Boost LED Current vs Input Voltage
VO = 32 V (9 LEDs)
LM3429 LM3429-Q1 300944b9.gif
Figure 5. Analog Dimming
VO = 20 V (6 LEDs)
LM3429 LM3429-Q1 300944b0.gif
Figure 7. VCSH vs. Junction Temperature
LM3429 LM3429-Q1 300944b2.gif
Figure 9. VRCT vs. Junction Temperature
LM3429 LM3429-Q1 300944b4.gif
Figure 11. tON-MIN vs. Junction Temperature
LM3429 LM3429-Q1 300944b5.gif
Figure 2. Buck-Boost Efficiency vs Input Voltage
VO = 20 V (6 LEDs)
LM3429 LM3429-Q1 300944b7.gif
Figure 4. Buck-boost LED Current vs Input Voltage
VO = 20 V (6 LEDs)
LM3429 LM3429-Q1 300944c0.gif
Figure 6. PWM Dimming
VO = 20V (6 LEDs)
LM3429 LM3429-Q1 300944b1.gif
Figure 8. VCC vs. Junction Temperature
LM3429 LM3429-Q1 300944b3.gif
Figure 10. VLIM vs. Junction Temperature