SLVS441D December   2002  – December  2014

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Typical Application
  5. 5 Revision History
  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 Boost Converter
      2. 8.3.2 Peak Current Control (Boost Converter)
      3. 8.3.3 Softstart
      4. 8.3.4 Control (CTRL)
      5. 8.3.5 Applying a PWM Signal to the CTRL Pin with an On-Time tp≤2.5µs
    4. 8.4 Device Functional Modes
      1. 8.4.1 Overvoltage Protection (OVP)
      2. 8.4.2 Undervoltage Lockout
      3. 8.4.3 Thermal Shutdown
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Efficiency
      2. 9.1.2 Setting The LED Current
      3. 9.1.3 PWM Control With Separate Enable
      4. 9.1.4 Example Schematics
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Inductor Selection, Maximum Load Current, and Switching Frequency
        2. 9.2.2.2 Output Capacitor Selection and Line Regulation
        3. 9.2.2.3 Input Capacitor Selection
        4. 9.2.2.4 Diode Selection
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
      1. 11.2.1 Thermal Considerations
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Trademarks
    4. 12.4 Electrostatic Discharge Caution
    5. 12.5 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

7 Specifications

7.1 Absolute Maximum Ratings

over operating free-air temperature range (unless otherwise noted) (1)
MIN MAX UNIT
V(VIN) Supply voltages (2) –0.3 7 V
V(Rs) , V(CTRL), V(FB) Voltages –0.3 Vin + 0.3 V
V(SW), V(LED) Voltages(2) 30 V
V(OVP) Voltage 30 V
Continuous power dissipation See Thermal Information Table
Operating junction temperature range –40 150 °C
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) All voltage values are with respect to network ground terminal.

7.2 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.

7.3 Recommended Operating Conditions

over operating free-air temperature range (unless otherwise noted)
MIN TYP MAX UNIT
VI Input voltage range 1.8 6 V
Vs Output voltage range VIN 27.5 V
VSW Switch voltage 30 V
I(LED) Maximum LED switch current 60 mA
L Inductor(1) 4.7 µH
f Switching frequency(1) 1 MHz
CI Input capacitor(1) 4.7 µF
CO Output capacitor(1) 100 nF
TA Operating ambient temperature –40 85 °C
TJ Operating junction temperature –40 125 °C
(1) See application section for further information.

7.4 Thermal Information

THERMAL METRIC(1) TPS61042 UNIT
DRB PACKAGE
8 PINS
RθJA Junction-to-ambient thermal resistance 48.6 °C/W
RθJC(top) Junction-to-case (top) thermal resistance 66.9
RθJB Junction-to-board thermal resistance 23.8
ψJT Junction-to-top characterization parameter 1.5
ψJB Junction-to-board characterization parameter 23.9
RθJC(bot) Junction-to-case (bottom) thermal resistance 5.2
(1) For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953.

7.5 Electrical Characteristics

VI = 3.6 V, CTRL= VI, TA = -40°C to + 85°C, typical values are at TA= 25°C (unless otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
SUPPLY CURRENT
VI Input voltage range 1.8 6.0 V
I(Q) Operating quiescent current into VIN IO = 0 mA, not switching 38 65 µA
IO(sd) Shutdown current CTRL = GND 0.1 1 µA
VUVLO Under-voltage lockout threshold VI falling 1.5 1.7 V
CTRL
VIH CTRL high level input voltage 1.3 V
VIL CTRL low level input voltage 0.3 V
IIkg CTRL input leakage current CTRL = GND or VIN 0.1 µA
ton Minimum CTRL pulse width to enable CTRL = low to high 50 µs
toff Minimum CTRL pulse width to disable CTRL = high to low 10 32 ms
f(CTRL) PWM switching frequency applied to CTRL 0.1 50 kHz
D(CTRL) PWM duty cycle applied to CTRL 1% 100%
POWER SWITCH AND CURRENT LIMIT (SW)
VS Maximum switch voltage 30 V
rds(ON) MOSFET on-resistance VI = 3.6 V; I(SW) = 200 mA 300 600 mΩ
Ilkg MOSFET leakage current V(SW) = 28 V 0.1 10 µA
ILIM MOFSET current limit 400 500 600 mA
LED SWITCH AND CURRENT LIMIT (LED)
VS Maximum switch voltage 30 V
rds(ON) MOSFET on-resistance VI = 3.6 V; IS = 20 mA 1 2 Ω
Ilkg MOSFET leakage current V(LED)= 28 V 0.1 10 µA
OUTPUT
VO Output voltage range VI 27.5 V
I(FB) Feedback input bias current(1) V(FB) = 0.252 V 100 nA
VFB Feedback trip point voltage 1.8 V ≤ VI≤ 6 V 244 252 260 mV
V(OVP) Output overvoltage protection VO rising 27.5 29 30 V
Vhys(OVP) Output overvoltage protection hysteresis 5 7 V
I(OVP) OVP input current VO = 15 V 9 12 µA
(1) The feedback input is high impedance MOSFET Gate input.

7.6 Typical Characteristics

Table 1. Table of Graphs

FIGURE
η Efficiency vs LED current Figure 1
vs Input voltage Figure 2
IQ Operating Quiescent Current into VIN vs Input voltage and Temperature Figure 3
V(FB) Feedback voltage vs Temperature Figure 4
I(FB) Feedback current vs Temperature Figure 5
rds(on) Main switch Q1 vs Temperature Figure 6
vs Input voltage Figure 7
LED switch Q2 vs Temperature Figure 8
vs Input voltage Figure 9
ILED Average LED current vs PWM duty cycle on CTRL pin Figure 10
Effvscurrent_lvs441.gif
Figure 1. Efficiency vs Output Current
Oqcvsinvolt_lvs441.gif
Figure 3. Operating Quiescent Current into VIN
vs Input Voltage and Temperature
Effvsinvolt_lvs441.gif
Figure 2. Efficiency vs Input Voltage
Fbvvstemp_lvs441.gif
Figure 4. Feedback Voltage vs Temperature
Fbcvstemp_lvs441.gif
Figure 5. Feedback Current vs Temperature
Rdsq1involt_lvs441.gif
Figure 7. rds(ON) Main Switch (Q1) vs Input Voltage
Rdsq2involt_lvs441.gif
Figure 9. rds(on) LED Switch (Q2) vs Input Voltage
Rdsq1temp_lvs441.gif
Figure 6. rds(on) Main Switch (Q1) vs Temperature
Rdsq2temp_lvs441.gif
Figure 8. rds(on) LED Switch (Q2) vs Temperature
Iledvspwm_lvs441.gif
Figure 10. Average LED Current vs PWM Duty Cycle on CTRL Pin