SLVSBM5B December   2012  – August 2015 TPS61176

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 Supply Voltage
      2. 7.3.2 Boost Converter
      3. 7.3.3 Current Sinks
      4. 7.3.4 IFBx Pin Unused
      5. 7.3.5 Enable and Start-up
      6. 7.3.6 Brightness Dimming Control
    4. 7.4 Device Functional Modes
      1. 7.4.1 Dimming Modes
        1. 7.4.1.1 Analog Dimming Mode
        2. 7.4.1.2 PWM Dimming
      2. 7.4.2 Overvoltage Protection
      3. 7.4.3 Current Sink Open Protection
      4. 7.4.4 Overcurrent and Short Circuit Protection
      5. 7.4.5 Thermal Protection
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Single-Cell Battery Input Application
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Inductor Selection
          2. 8.2.1.2.2 Output Capacitor Selection
          3. 8.2.1.2.3 Schottky Diode Selection
          4. 8.2.1.2.4 Isolation FET Selection
          5. 8.2.1.2.5 Audible Noise Reduction
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Multi-Cell Battery Input Application
      3. 8.2.3 Combined String Application
      4. 8.2.4 Separate PWM and EN Signals Application
  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 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
    2. 11.2 Community Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 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
Voltage range(2) VIN, PWM/EN, MODE/FAULT –0.3 7 V
SW –0.3 40 V
IFB1 to IFB6 –0.3 20 V
All other pins –0.3 3.6 V
Continuous power dissipation See Thermal Information
Operating junction temperature –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.

6.2 ESD Ratings

VALUE UNIT
V(ESD) Electrostatic discharge Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001(1) ±4000 V
Charged-device model (CDM), per JEDEC specification JESD22-C101(2) ±2000
Machine model ±200
(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 NOM MAX UNIT
VIN Bias voltage to device (see Figure 18) 2.7 6.5 V
Input voltage to inductor (see Figure 18) 2.7 24 V
VOUT Output voltage range VIN 38 V
L Inductor 4.7 6.8 10 µH
CI Input capacitor 1.0 2.2 µF
CO Output capacitor 2.2 4.7 10 µF
CCOMP COMP capacitor 0.47 1 µF
FPWM_I Input PWM signal frequency 0.1 22 kHz
TA Operating ambient temperature –40 85 °C
TJ Operating junction temperature –40 125 °C

6.4 Thermal Information

THERMAL METRIC(1) TPS61176 UNIT
RTE (WQFN)
16 PINS
RθJA Junction-to-ambient thermal resistance 43 °C/W
RθJC(top) Junction-to-case (top) thermal resistance 44.4 °C/W
RθJB Junction-to-board thermal resistance 14.4 °C/W
ψJT Junction-to-top characterization parameter 0.6 °C/W
ψJB Junction-to-board characterization parameter 14.3 °C/W
RθJC(bot) Junction-to-case (bottom) thermal resistance 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

VIN = 3.6 V, PWM/EN = high, IFB current = 20 mA, IFB voltage = 450 mV, TA = –40°C to +85°C, typical values are at TA = 25°C (unless otherwise noted).
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
POWER SUPPLY
VIN Input voltage range 2.7 6.5 V
VIN_UVLO VIN undervoltage lockout threshold VIN ramp down 2.4 2.5 V
VIN ramp up 2.65 2.7
VIN_HYS VIN undervoltage lockout hysteresis 250 mV
Iq_VIN Operating quiescent current into VIN Device enable, switching 1 MHz and no load 3 mA
ISD Shutdown current PWM/EN = low 1 4 µA
PWM/EN = low, TA = 25°C 1 2
VLDO VLDO pin output voltage VIN = 3.6 V 3 3.3 3.5 V
PWM/EN
VH PWM/EN logic high 1.2 V
VL PWM/EN logic Low 0.4 V
RPD PWM/EN pin internal pull-down resistor 400 800 1600 kΩ
tSD PWM/EN logic low width to shutdown PWM/EN from high to low 20 ms
CURRENT REGULATION
VISET ISET pin voltage PWM/EN logic high 1.02 1.04 1.06 V
KISET Current multiplier IISET = 20 μA 1024
IFBx Current accuracy IISET = 20 μA, 0°C to 70°C –2% 2%
IISET = 20 µA, –40°C to 85°C –2.3% 2.3%
Km (IMAX – IMIN) / (2 x IAVG) IISET = 20 μA 0.65%
IIFBx_leak IFBx pin leakage current VIFBx = 10 V, each pin 1.5 5 µA
VIFBx = 5 V, each pin 0.5 2
IIFBx_max Current sink max output current IISET = 35 μA, each pin 35 mA
TFBx_MINON Current sink minimum on time IISET = 20 μA, each pin 0.5 µs
fdim PWM dimming frequency Mode 1 / Mode 3, 0°C to 70°C 20 22 27 kHz
BOOST OUTPUT REGULATION
VIFBx_min IFBx regulation voltage Measured on VIFB(MIN), IISET = 20 μA 450 mV
POWER SWITCH
RDS(on) Switch MOSFET on-resistance VIN = 3.6 V 0.25 0.4 Ω
ILEAK_SW Switch MOSFET leakage current VSW = 40 V 2 µA
OSCILLATOR
fSW Oscillator frequency 0.8 1 1.2 MHz
Dmax Maximum boost switch duty cycle 93%
MODE/FAULT
VMODE MODE/FAULT pin voltage during mode detection period Tested as VIN – VMODE when mode resistor is connected between VIN pin and MODE/FAULT pin; Tested as VMODE when mode resistor is connected between MODE/FAULT pin and GND 0.6 0.9 V
IMODE_PD MODE/FAULT pin pulldown current after mode detection VMODE = 0.5 V, mode resistor is connected between VIN pin and MODE/FAULT pin 50 80 µA
OC, SC, OVP and SS
ILIM Switch MOSFET current limit 2 2.5 3 A
VOVP_clamp Output overvoltage clamp threshold 1.47 1.5 1.53 V
VOVP_sd Output overvoltage shutdown threshold OVP ramp up 1.568 1.6 1.632 V
OVP ramp down 1.519 1.55 1.581
VOVP_SC Output short to GND detection threshold OVP ramp up 90 mV
OVP ramp down 50 70
VOVP_IFB 1st level IFB overvoltage threshold IFBx current sink on 7 8.5 10 V
VOVP2_IFB 2nd level IFB overvoltage threshold IFBx current sink on or off 16 18 20 V
THERMAL SHUTDOWN
Tshutdown Thermal shutdown threshold 160 °C
Thys Thermal shutdown hysteresis 15 °C

6.6 Typical Characteristics

Table 1. Table Of Graphs

TITLE DESCRIPTION FIGURE
Dimming Efficiency VBAT = 3 V, 3.6 V, 4.2 V, 5 V; VO = 18 V, 6s6p, 20 mA/string; PWM Freq = 200 Hz; Mode 1;
L = 6.8 µH		 Figure 1
Dimming Efficiency VBAT = 3 V, 3.6 V, 4.2 V, 5 V; VO = 21 V, 7s6p, 20 mA/string; PWM Freq = 200 Hz; Mode 1;
L = 6.8µH		 Figure 2
Dimming Efficiency VBAT = 3 V, 3.6 V, 4.2 V, 5 V; VO = 24 V, 8s5p, 20 mA/string; PWM Freq = 200 Hz; Mode 1;
L = 6.8 µH		 Figure 3
Dimming Efficiency VBAT = 3 V, 3.6 V, 4.2 V, 5 V; VO = 27 V, 9s4p, 20 mA/string; PWM Freq = 20 0Hz; Mode 1;
L = 6.8µH		 Figure 4
Dimming Efficiency VIN = 5 V; VBAT = 3 V, 3.6 V, 4.2 V, 5 V, 7.2 V, 9 V, 12 V, 15 V; VO = 18 V, 6s6p, 20 mA/string; PWM Freq = 200 Hz;
Mode 1; L = 6.8 µH (refer to Figure 18)		 Figure 5
Dimming Linearity VBAT = 3 V, 3.6 V, 4.2 V, 5 V; VO = 21 V, 7s6p; RISET = 53 kΩ ; PWM Freq = 200 Hz;
Mode 1		 Figure 6
Current Limit vs Input Voltage VO = 30 V; TA = 25°C Figure 7
Switching Waveform VBAT = 3.6 V; VO = 18 V, 6s6p; RISET = 53 kΩ; Duty = 100%; L = 6.8 µH Figure 11
Switching Waveform VBAT = 3.6 V; VO = 18 V, 6s6p; RISET = 53 kΩ; PWM Freq = 200 Hz; Duty = 50%; L = 6.8 µH;
Mode 1		 Figure 12
Switching Waveform VBAT = 3.6 V; VO = 18 V, 6s6p; RISET = 53 kΩ; PWM Freq = 200 Hz; Duty = 10%; L = 6.8 µH;
Mode 1		 Figure 13
Switching Waveform VBAT = 3.6 V; VO = 18 V, 6s6p; RISET = 53 kΩ; PWM Freq = 200 Hz; Duty = 50%; L = 6.8 µH;
Mode 2		 Figure 14
Switching Waveform VBAT = 3.6 V; VO = 18 V, 6s6p; RISET = 53 kΩ; PWM Freq = 200Hz; Duty = 10%; L = 6.8 µH;
Mode 2		 Figure 15
Start-up Waveform VBAT = 3.6 V; VO = 18 V, 6s6p; RISET = 53 kΩ; Duty = 100%; L = 6.8 µH Figure 16
Start-up Waveform VBAT = 3.6 V; VO = 18 V, 6s6p; RISET = 53 kΩ; PWM Freq = 200 Hz; Duty = 10%; L = 6.8 µH;
Mode 1		 Figure 17
TPS61176 C001_SLVSBM5.png
Figure 1. Efficiency vs Dimming Duty Cycle
TPS61176 C002_SLVSBM5.png
Figure 2. Efficiency vs Dimming Duty Cycle
TPS61176 C003_SLVSBM5.png
Figure 3. Efficiency vs Dimming Duty Cycle
TPS61176 C005_SLVSBM5.png
Figure 5. Efficiency vs Dimming Duty Cycle
TPS61176 C007_SLVSBM5.png
Figure 7. Switch Current Limit vs Input Voltage
TPS61176 C004_SLVSBM5.png
Figure 4. Efficiency vs Dimming Duty Cycle
TPS61176 C006_SLVSBM5.png
Figure 6. Dimming Linearity