SLVS859B June   2008  – December 2014 TPS61085

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Simplified Schematic
  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 Soft-Start
      2. 8.3.2 Frequency Select Pin (FREQ)
      3. 8.3.3 Undervoltage Lockout (UVLO)
      4. 8.3.4 Thermal Shutdown
      5. 8.3.5 Overvoltage Prevention
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Design Procedure
        2. 9.2.2.2 Inductor Selection
        3. 9.2.2.3 Rectifier Diode Selection
        4. 9.2.2.4 Setting the Output Voltage
        5. 9.2.2.5 Compensation (COMP)
        6. 9.2.2.6 Input Capacitor Selection
        7. 9.2.2.7 Output Capacitor Selection
      3. 9.2.3 Application Curves
    3. 9.3 System Examples
      1. 9.3.1 General Boost Application Circuits
      2. 9.3.2 TFT LCD Application Circuit
      3. 9.3.3 WHITE LED Application Circuits
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Trademarks
    2. 12.2 Electrostatic Discharge Caution
    3. 12.3 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
Input voltage range IN –0.3 7 V
Voltage range on pins EN, FB, SS, FREQ, COMP –0.3 7 V
Voltage on pin SW -0.3 20 V
Continuous power dissipation See Thermal Information
Operating junction temperature –40 150 °C
Storage temperature –65 150 °C
(1) Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under recommended operating conditions is not implied. 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) ±500
Machine model (MM) ±200
(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process. Manufacturing with less than 500-V HBM is possible with the necessary precautions. Pins listed as ±XXX V may actually have higher performance.
(2) JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process. Manufacturing with less than 250-V CDM is possible with the necessary precautions. Pins listed as ±YYY V may actually have higher performance.

7.3 Recommended Operating Conditions

MIN TYP MAX UNIT
VIN Input voltage range 2.3 6 V
VS Boost output voltage range VIN + 0.5 18.5 V
TA Operating free-air temperature –40 85 °C
TJ Operating junction temperature –40 125 °C

7.4 Thermal Information

THERMAL METRIC(1) TPS61085 UNIT
DGK PW
8 PINS 8 PINS
RθJA Junction-to-ambient thermal resistance 189.3 183.3 °C/W
RθJC(top) Junction-to-case (top) thermal resistance 57.1 66.7
RθJB Junction-to-board thermal resistance 109.9 112.0
ψJT Junction-to-top characterization parameter 3.5 8.3
ψJB Junction-to-board characterization parameter 108.3 110.3
(1) For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953.

7.5 Electrical Characteristics

VIN = 3.3 V, EN = VIN, VS = 12 V, TA = –40°C to 85°C, typical values are at TA = 25°C (unless otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
SUPPLY
VIN Input voltage range 2.3 6 V
IQ Operating quiescent current into IN Device not switching, VFB = 1.3 V 70 100 μA
ISDVIN Shutdown current into IN EN = GND 1 μA
UVLO Undervoltage lockout threshold VIN falling 2.2 V
VIN rising 2.3 V
TSD Thermal shutdown Temperature rising 150 °C
TSD(HYS) Thermal shutdown hysteresis 14 °C
LOGIC SIGNALS EN, FREQ
VIH High level input voltage VIN = 2.3 V to 6 V 2 V
VIL Low level input voltage VIN = 2.3 V to 6 V 0.5 V
Ilkg Input leakage current EN = FREQ = GND 0.1 μA
BOOST CONVERTER
VS Boost output voltage VIN + 0.5 18.5 V
VFB Feedback regulation voltage 1.230 1.238 1.246 V
gm Transconductance error amplifier 107 μA/V
IFB Feedback input bias current VFB = 1.238 V 0.1 μA
rDS(on) N-channel MOSFET on-resistance VIN = VGS = 5 V, ISW = current limit 0.13 0.20 Ω
VIN = VGS = 3.3V, ISW = current limit 0.15 0.24
Ilkg SW leakage current EN = GND, VSW = 6V TBD 10 µA
ILIM N-Channel MOSFET current limit 2.0 2.6 3.2 A
ISS Soft-start current VSS = 1.238 V 7 10 13 μA
fS Oscillator frequency FREQ = VIN 0.9 1.2 1.5 MHz
FREQ = GND 480 650 820 kHz
Line regulation VIN = 2.3 V to 6 V, IOUT = 10 mA 0.0002 %/V
Load regulation VIN = 3.3 V, IOUT = 1 mA to 400 mA 0.11 %/A

7.6 Typical Characteristics

The typical characteristics are measured with the inductors 7447789003 3.3 µH (high frequency) or B82464G4 6.8 µH (low frequency) from Epcos and the rectifier diode SL22.

Table 1. Table Of Graphs

FIGURE
IOUT(max) Maximum load current vs Input voltage at high frequency (1.2 MHz) Figure 1
vs Input voltage at low frequency (650 kHz) Figure 2
η Efficiency vs Load current, VS = 12 V, VIN = 3.3 V Figure 3
vs Load current, VS = 9 V, VIN = 3.3 V Figure 4
Supply current vs Supply voltage Figure 5
Frequency vs Load current Figure 6
Frequency vs Supply voltage Figure 7
61085HFmaxI.pngFigure 1. Maximum Load Current vs Input Voltage
61085LFmaxI.pngFigure 2. Maximum Load Current vs Input Voltage
eff_io_lvs859.gifFigure 3. Efficiency vs Load Current
icc_vcc_lvs859.gifFigure 5. Supply Current vs Supply Voltage
f_vi_lvs859.gifFigure 7. Frequency vs Supply Voltage
eff2_io_lvs859.gifFigure 4. Efficiency vs Load Current
f_io_lvs859.gifFigure 6. Frequency vs Load Current