SLVSB58B March   2012  – January  2016 TPS54040A

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  Fixed Frequency PWM Control
      2. 7.3.2  Slope Compensation Output Current
      3. 7.3.3  Bootstrap Voltage (BOOT)
      4. 7.3.4  Low Dropout Operation
      5. 7.3.5  Error Amplifier
      6. 7.3.6  Voltage Reference
      7. 7.3.7  Adjusting the Output Voltage
      8. 7.3.8  Enable and Adjusting Undervoltage Lockout
      9. 7.3.9  Slow Start/Tracking Pin (SS/TR)
      10. 7.3.10 Overload Recovery Circuit
      11. 7.3.11 Sequencing
      12. 7.3.12 Constant Switching Frequency and Timing Resistor (RT/CLK Pin)
      13. 7.3.13 Overcurrent Protection and Frequency Shift
      14. 7.3.14 Selecting the Switching Frequency
      15. 7.3.15 How to Interface to RT/CLK Pin
      16. 7.3.16 Power Good (PWRGD Pin)
      17. 7.3.17 Overvoltage Transient Protection
      18. 7.3.18 Thermal Shutdown
      19. 7.3.19 Small Signal Model for Loop Response
      20. 7.3.20 Simple Small Signal Model for Peak Current Mode Control
      21. 7.3.21 Small Signal Model for Frequency Compensation
    4. 7.4 Device Functional Modes
      1. 7.4.1 Pulse-Skip Eco-Mode
      2. 7.4.2 Normal Operation
      3. 7.4.3 Standby Operation
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1  Selecting the Switching Frequency
        2. 8.2.2.2  Output Inductor Selection (LO)
        3. 8.2.2.3  Output Capacitor
        4. 8.2.2.4  Catch Diode
        5. 8.2.2.5  Input Capacitor
        6. 8.2.2.6  Slow Start Capacitor
        7. 8.2.2.7  Bootstrap Capacitor Selection
        8. 8.2.2.8  Under Voltage Lock Out Set Point
        9. 8.2.2.9  Output Voltage and Feedback Resistors Selection
        10. 8.2.2.10 Compensation
        11. 8.2.2.11 Power Dissipation Estimate
      3. 8.2.3 Application Curves
    3. 8.3 System Examples
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 Estimated Circuit Area
  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(1)

over operating temperature range (unless otherwise noted).
MIN MAX UNIT
Input voltage VIN –0.3 47 V
EN –0.3 5
BOOT 55
VSENSE –0.3 3
COMP –0.3 3
PWRGD –0.3 6
SS/TR –0.3 3
RT/CLK –0.3 3.6
Output voltage BOOT-PH 8 V
PH –0.6 47
PH, 10-ns Transient –2 47
Voltage Difference PAD to GND ±200 mV
Source current EN 100 μA
BOOT 100 mA
VSENSE 10 μA
PH Current Limit A
RT/CLK 100 μA
Sink current VIN Current Limit A
COMP 100 μA
PWRGD 10 mA
SS/TR 200 μA
Electrostatic Discharge (HBM) QSS 009-105 (JESD22-A114A) 2 kV
Electrostatic Discharge (CDM) QSS 009-147 (JESD22-C101B.01) 500 V
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.

6.2 ESD Ratings

VALUE UNIT
V(ESD) Electrostatic discharge Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001(1) ±1000 V
Charged-device model (CDM), per JEDEC specification JESD22-C101(2) ±500
(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 supply voltage 3.5 42 V
Output current capability 0.5 A
Output voltage range for adjustable voltage 0.8 VIN V
Effective input capacitance 3 µF
Operating junction temperature, TJ –40 150 °C

6.4 Thermal Information

THERMAL METRIC(1) TPS54040A UNIT
DGQ (MSOP-PowerPAD) DRC (VSON)
10 PINS 10 PINS
θJA Junction-to-ambient thermal resistance (standard board) 62.5 40 °C/W
θJCtop Junction-to-case (top) thermal resistance 83 65 °C/W
θJB Junction-to-board thermal resistance 28 8 °C/W
ψJT Junction-to-top characterization parameter 1.7 0.6 °C/W
ψJB Junction-to-board characterization parameter 20.1 7.5 °C/W
θJCbot Junction-to-case (bottom) thermal resistance 21 7.8 °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

TJ = –40°C to 150°C, VIN = 3.5 to 42V (unless otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
SUPPLY VOLTAGE (VIN PIN)
Operating input voltage 3.5 42 V
Internal undervoltage lockout threshold No voltage hysteresis, rising and falling 2.5 V
Shutdown supply current EN = 0 V, 25°C, 3.5 V ≤ VIN ≤ 42 V 1.3 4 μA
Operating : nonswitching supply current VSENSE = 0.83 V, VIN = 12 V, 25°C 116 136
ENABLE AND UVLO (EN PIN)
Enable threshold voltage No voltage hysteresis, rising and falling 1.11 1.25 1.36 V
Input current Enable threshold +50 mV –3.8 μA
Enable threshold –50 mV –0.9
Hysteresis current 1.91 2.95 3.99 μA
VOLTAGE REFERENCE
Voltage reference TJ = 25°C 0.792 0.8 0.808 V
0.784 0.8 0.816
HIGH-SIDE MOSFET
On-resistance VIN = 3.5 V, BOOT-PH = 3 V 300 mΩ
VIN = 12 V, BOOT-PH = 6 V 200 410
ERROR AMPLIFIER
Input current 50 nA
Error amplifier transconductance (gM) –2 μA < ICOMP < 2 μA, VCOMP = 1 V 97 μMhos
Error amplifier transconductance (gM) during slow start –2 μA < ICOMP < 2 μA, VCOMP = 1 V,
VVSENSE = 0.4 V		 26 μMhos
Error amplifier dc gain VVSENSE = 0.8 V 10,000 V/V
Error amplifier bandwidth 2700 kHz
Error amplifier source/sink V(COMP) = 1 V, 100 mV overdrive ±7 μA
COMP to switch current transconductance 1.9 A/V
CURRENT LIMIT
Current limit threshold VIN = 12 V, TJ = 25°C 0.6 0.94 A
THERMAL SHUTDOWN
Thermal shutdown 182 °C
TIMING RESISTOR AND EXTERNAL CLOCK (RT/CLK PIN)
Switching Frequency Range using RT mode 100 2500 kHz
fSW Switching frequency RT = 200 kΩ 450 581 720 kHz
Switching Frequency Range using CLK mode 300 2200 kHz
Minimum CLK input pulse width 40 ns
RT/CLK high threshold 1.9 2.2 V
RT/CLK low threshold 0.45 0.7 V
RT/CLK falling edge to PH rising edge delay Measured at 500 kHz with RT resistor in series 60 ns
PLL lock in time Measured at 500 kHz 100 μs
SLOW START AND TRACKING (SS/TR)
Charge current V(SS/TR) = 0.4 V 2 μA
SS/TR-to-VSENSE matching V(SS/TR) = 0.4 V 45 mV
SS/TR-to-reference crossover 98% nominal 1.0 V
SS/TR discharge current (overload) VSENSE = 0 V, V(SS/TR) = 0.4 V 112 μA
SS/TR discharge voltage VSENSE = 0 V 54 mV
POWER GOOD (PWRGD PIN)
VVSENSE VSENSE threshold VSENSE falling 92%
VSENSE rising 94%
VSENSE rising 109%
VSENSE falling 107%
Hysteresis VSENSE falling 2%
Output high leakage VSENSE = VREF, V(PWRGD) = 5.5 V, 25°C 10 nA
On resistance I(PWRGD) = 3 mA, VSENSE < 0.79 V 50 Ω
Minimum VIN for defined output V(PWRGD) < 0.5 V, I(PWRGD) = 100 μA 0.95 1.5 V

6.6 Typical Characteristics

TPS54040A rdson_tj_lvs795.gif Figure 1. ON Resistance vs Junction Temperature
TPS54040A imax_tj_lvs919.gif Figure 3. Switch Current Limit vs Junction Temperature
TPS54040A fs_rt_clk_lvs795.gif Figure 5. Switching Frequency vs RT/CLK Resistance High Frequency Range
TPS54040A ea_tj_lvs795.gif Figure 7. EA Transconductance During Slow Start vs Junction Temperature
TPS54040A en_tj_lvs795.gif Figure 9. EN Pin Voltage vs Junction Temperature
TPS54040A ic2_tj_lvs795.gif Figure 11. EN Pin Current vs Junction Temperature
TPS54040A ss_tr2_tj_lvs795.gif Figure 13. SS/TR Discharge Current vs Junction Temperature
TPS54040A icc_tj_lvs795.gif Figure 15. Shutdown Supply Current vs Junction Temperature
TPS54040A icc2_tj_lvs795.gif Figure 17. VIN Supply Current vs Junction Temperature
TPS54040A rdson2_tj_lvs795.gif Figure 19. PWRGD ON Resistance vs Junction Temperature
TPS54040A boot_tj_lvsb58.gif Figure 21. BOOT-PH UVLO vs Junction Temperature
TPS54040A offset_vs_lvs795.gif Figure 23. SS/TR to VSENSE Offset vs VSENSE
TPS54040A vref_tj_lvs795.gif Figure 2. Voltage Reference vs Junction Temperature
TPS54040A fs_tj_lvs795.gif Figure 4. Switching Frequency vs Junction Temperature
TPS54040A fs_rt_clk2_lvs919.gif Figure 6. Switching Frequency vs RT/CLK Resistance Low Frequency Range
TPS54040A ea2_tj_lvs795.gif Figure 8. EA Transconductance vs Junction Temperature
TPS54040A ic_tj_lvs795.gif Figure 10. EN Pin Current vs Junction Temperature
TPS54040A ss_tr_tj_lvs795.gif Figure 12. SS/TR Charge Current vs Junction Temperature
TPS54040A fs_vsense_lvs795.gif Figure 14. Switching Frequency vs VSENSE
TPS54040A icc_vi_lvs918.gif Figure 16. Shutdown Supply Current vs Input Voltage (Vin)
TPS54040A icc_vi2_lvs918.gif Figure 18. VIN Supply Current vs Input Voltage
TPS54040A pwrgd_tj_lvs795.gif Figure 20. PWRGD Threshold vs Junction Temperature
TPS54040A uvlo_tj_lvs795.gif Figure 22. Input Voltage (UVLO) vs Junction Temperature
TPS54040A offset_tj_lvs795.gif Figure 24. SS/TR to VSENSE OFFSET vs Temperature