TPS54040ADGQ

Manufacturer Part NumberTPS54040ADGQ
Description
ManufacturerTI1 [Texas Instruments]
TPS54040ADGQ datasheet
 


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0.5 A, 42 V Step Down SWIFT™ DC/DC Converter with ECO-MODE™
FEATURES
1
• 3.5 V to 42 V Input Voltage Range
23
200-mΩ High-Side MOSFET
High Efficiency at Light Loads with a Pulse
Skipping Eco-Mode™
Tighter Enable Threshold than TPS54040
for More Accurate UVLO Voltage
Adjustable UVLO Voltage and Hysteresis
116 μA Operating Quiescent Current
1.3 μA Shutdown Current
100 kHz to 2.5 MHz Switching Frequency
Synchronizes to External Clock
Adjustable Slow Start/Sequencing
UV and OV Power Good Output
DESCRIPTION
The TPS54040A device is a 42 V, 0.5 A, step down regulator with an integrated high side MOSFET. Current
mode control provides simple external compensation and flexible component selection. A low ripple pulse skip
mode reduces the no load, regulated input supply current to 116 μA. Using the enable pin, shutdown supply
current is nominally 1.3 μA when the enable pin is low.
Under voltage lockout is internally set at 2.5 V, but can be increased using the enable pin. The output voltage
startup ramp is controlled by the slow start pin that can also be configured for sequencing or tracking. An open
drain power good signal indicates when the output is within 94% to 107% of its nominal voltage.
A wide switching frequency range allows efficiency and external component size to be optimized. Frequency fold
back and thermal shutdown protects the part during an overload condition.
SPACER
SIMPLIFIED SCHEMATIC
V
VIN
VIN
PWRGD
IN
TPS54040A
BOOT
EN
PH
SS /TR
RT /CLK
COMP
VSENSE
GND
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
Eco-Mode, SwitcherPro, SWIFT are trademarks of Texas Instruments.
2
WEBENCH is a registered trademark of Texas Instruments.
3
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Check for Samples:
TPS54040A
0.8-V Internal Voltage Reference
Available in MSOP-10 and VSON-10 Packages
Supported by WEBENCH
Software Tool
For SWIFT™ Documentation, See the TI
Website at
http://www.ti.com/swift
APPLICATIONS
12-V and 24-V Industrial and Commercial Low
Power Systems
Aftermarket Auto Accessories: Video, GPS,
Entertainment
100
90
80
V
OUT
70
60
50
40
30
20
10
0
0
0.1
TPS54040A
SLVSB58 – MARCH 2012
®
and SwitcherPro™
EFFICIENCY
vs
LOAD CURRENT
V = 12 V,
I
V = 5.0 V,
O
f
= 700 kHz
sw
0.2
0.3
0.4
0.5
Load Current - A
Copyright © 2012, Texas Instruments Incorporated

TPS54040ADGQ Summary of contents

  • Page 1

    Step Down SWIFT™ DC/DC Converter with ECO-MODE™ FEATURES 1 • 3 Input Voltage Range 23 • 200-mΩ High-Side MOSFET • High Efficiency at Light Loads with a Pulse Skipping Eco-Mode™ • ...

  • Page 2

    ... For the most current package and ordering information see the Package Option Addendum at the end of this document, or see the TI website at www.ti.com. (2) The DGQ package is also available taped and reeled. Add an R suffix to the device type (i.e., TPS54040ADGQR). (3) The DRC package is available in large or small reels. Add an R suffix for large reels, and a T suffix for small reels (i.e., TPS54040ADRCR) ...

  • Page 3

    THERMAL INFORMATION THERMAL METRIC θ Junction-to-ambient thermal resistance (standard board) JA θ Junction-to-case (top) thermal resistance JCtop θ Junction-to-board thermal resistance JB ψ Junction-to-top characterization parameter JT ψ Junction-to-board characterization parameter JB θ Junction-to-case (bottom) thermal resistance JCbot (1) ...

  • Page 4

    TPS54040A SLVSB58 – MARCH 2012 ELECTRICAL CHARACTERISTICS (continued –40°C to 150°C, VIN = 3.5 to 42V (unless otherwise noted) J PARAMETER TIMING RESISTOR AND EXTERNAL CLOCK (RT/CLK PIN) Switching Frequency Range using RT mode f Switching frequency SW ...

  • Page 5

    PIN CONFIGURATION VSON-10 (TOP VIEW) BOOT 1 VIN 2 Thermal 3 EN Pad (11) SS/TR 4 RT/CLK 5 PIN I/O NAME NO. A bootstrap capacitor is required between BOOT and PH. If the voltage on this capacitor is below ...

  • Page 6

    TPS54040A SLVSB58 – MARCH 2012 FUNCTIONAL BLOCK DIAGRAM Shutdown UV Logic OV Voltage Reference ERROR AMPLIFIER VSENSE 7 SS/TR 4 Shutdown COMP 8 Maximum Overload Recovery 6 Submit Documentation Feedback PWRGD Enable Comparator Shutdown Enable Threshold Minimum ...

  • Page 7

    ON RESISTANCE vs JUNCTION TEMPERATURE 500 375 BOOT- 250 BOOT- 125 0 -50 - Junction Temperature - °C J Figure 1. SWITCH ...

  • Page 8

    TPS54040A SLVSB58 – MARCH 2012 TYPICAL CHARACTERISTICS (continued) EA TRANSCONDUCTANCE DURING SLOW START vs JUNCTION TEMPERATURE -50 - Junction Temperature - °C J Figure 7. ...

  • Page 9

    TYPICAL CHARACTERISTICS (continued) SS/TR DISCHARGE CURRENT vs JUNCTION TEMPERATURE 120 115 110 105 100 -50 - Junction Temperature - °C J Figure 13. SHUTDOWN SUPPLY CURRENT vs JUNCTION ...

  • Page 10

    TPS54040A SLVSB58 – MARCH 2012 TYPICAL CHARACTERISTICS (continued) PWRGD ON RESISTANCE vs JUNCTION TEMPERATURE 100 - - Junction Temperature - °C J Figure 19. ...

  • Page 11

    The TPS54040A device is a 42-V, 0.5-A, step-down (buck) regulator with an integrated high side n-channel MOSFET. To improve performance during line and load transients the device implements a constant frequency, current mode control which reduces output capacitance and ...

  • Page 12

    TPS54040A SLVSB58 – MARCH 2012 Fixed Frequency PWM Control The TPS54040A uses an adjustable fixed frequency, peak current mode control. The output voltage is compared through external resistors on the VSENSE pin to an internal voltage reference by an error ...

  • Page 13

    DETAILED DESCRIPTION (continued) Low Dropout Operation and Bootstrap Voltage (BOOT) The TPS54040A has an integrated boot regulator, and requires a small ceramic capacitor between the BOOT and PH pins to provide the gate drive voltage for the high side ...

  • Page 14

    TPS54040A SLVSB58 – MARCH 2012 DETAILED DESCRIPTION (continued) voltage is greater than 2 which point the BOOT UVLO threshold is exceeded, and the device starts switching again until the desired output voltage is reached. This operating condition persists ...

  • Page 15

    DETAILED DESCRIPTION (continued) Enable and Adjusting Undervoltage Lockout The TPS54040A is disabled when the VIN pin voltage falls below 2 application requires a higher undervoltage lockout (UVLO), use the EN pin as shown in the two ...

  • Page 16

    TPS54040A SLVSB58 – MARCH 2012 DETAILED DESCRIPTION (continued) V ENA START ENA ENA Slow Start/Tracking Pin (SS/TR) The TPS54040A effectively uses the lower voltage of the internal voltage ...

  • Page 17

    DETAILED DESCRIPTION (continued) Sequencing Many of the common power supply sequencing methods can be implemented using the SS/TR, EN and PWRGD pins. The sequential method can be implemented using an open drain output of a power on reset pin ...

  • Page 18

    TPS54040A SLVSB58 – MARCH 2012 DETAILED DESCRIPTION (continued) Figure 35. Schematic for Ratiometric and Simultaneous Start-Up Sequence Ratio-metric and simultaneous power supply sequencing can be implemented by connecting the resistor network of R1 and R2 shown in Figure 35 reference ...

  • Page 19

    DETAILED DESCRIPTION (continued) R1 > 2800 Vout1 180 ´ - ´ spacer EN Figure 36. Ratio-metric Startup with Tracking Resistors Figure 38. Simultaneous Startup With Tracking Resistor Copyright © 2012, Texas Instruments Incorporated deltaV VOUT1 VOUT2 Figure 37. Ratiometric ...

  • Page 20

    TPS54040A SLVSB58 – MARCH 2012 DETAILED DESCRIPTION (continued) Constant Switching Frequency and Timing Resistor (RT/CLK Pin) The switching frequency of the TPS54040A is adjustable over a wide range from approximately 100kHz to 2500kHz by placing a resistor on the RT/CLK ...

  • Page 21

    DETAILED DESCRIPTION (continued) Selecting the Switching Frequency The switching frequency that is selected should be the lower value of the two equations, Equation 13. Equation 12 is the maximum switching frequency limitation set by the minimum controllable on time. ...

  • Page 22

    TPS54040A SLVSB58 – MARCH 2012 DETAILED DESCRIPTION (continued) How to Interface to RT/CLK Pin The RT/CLK pin can be used to synchronize the regulator to an external system clock. To implement the synchronization feature connect a square wave to the ...

  • Page 23

    DETAILED DESCRIPTION (continued) PH EXT IL Figure 43. Plot of Synchronizing in ccm PH EXT Copyright © 2012, Texas Instruments Incorporated PH EXT Figure 44. Plot of Synchronizing in dcm IL Figure 45. Plot of Synchronizing in PSM Product ...

  • Page 24

    TPS54040A SLVSB58 – MARCH 2012 DETAILED DESCRIPTION (continued) Power Good (PWRGD Pin) The PWRGD pin is an open drain output. Once the VSENSE pin is between 94% and 107% of the internal voltage reference the PWRGD pin is de-asserted and ...

  • Page 25

    DETAILED DESCRIPTION (continued) COMP Figure 46. Small Signal Model for Loop Response Simple Small Signal Model for Peak Current Mode Control Figure 47 describes a simple small signal model that can be used to understand ...

  • Page 26

    TPS54040A SLVSB58 – MARCH 2012 DETAILED DESCRIPTION (continued) æ ö ç ÷ ´ è ø Z OUT = Adc ´ V æ ö ç ÷ ´ ...

  • Page 27

    DETAILED DESCRIPTION (continued) Aol A0 A1 Figure 49. Frequency Response of the Type 2A and Type 2B Frequency Compensation Aol(V/ (Hz) p ´ æ ç ...

  • Page 28

    TPS54040A SLVSB58 – MARCH 2012 Design Guide — Step-By-Step Design Procedure This example details the design of a high frequency switching regulator design using ceramic output capacitors. A few parameters must be known in order to start the design process. ...

  • Page 29

    Output Inductor Selection ( calculate the minimum value of the output inductor, use coefficient that represents the amount of inductor ripple current relative to the maximum output current. IND The inductor ripple current will ...

  • Page 30

    TPS54040A SLVSB58 – MARCH 2012 to see the change in load current and output voltage and adjust the duty cycle to react to the change. The output capacitor must be sized to supply the extra current to the load until ...

  • Page 31

    Catch Diode The TPS54040A requires an external catch diode between the PH pin and GND. The selected diode must have a reverse voltage rating equal to or greater than Vin max. The peak current rating of the diode must ...

  • Page 32

    TPS54040A SLVSB58 – MARCH 2012 VENDOR VALUE (μF) 1.0 to 2.2 1.0 to 4.7 Murata 1.0 1.0 to 2.2 1.0 10 1.8 1.0 to 1.2 Vishay 1.0 to 3.9 1.0 to 1.8 1.0 to 2.2 1.5 to 6.8 TDK 1.0. ...

  • Page 33

    The programmable UVLO and enable voltages are set using a resistor divider between Vin and ground to the EN pin. Equation 2 through Equation 3 application, a 332 kΩ between Vin and EN and a 56.2kΩ between EN and ...

  • Page 34

    TPS54040A SLVSB58 – MARCH 2012 Discontinuous Mode and Eco Mode Boundary With an input voltage the power supply enters discontinuous mode when the output current is less than 50mA. The power supply enters EcoMode when the output ...

  • Page 35

    Figure 57. Input Ripple DCM 100 Vin = 24 V Vin = Vin = 0.02 0.04 0. Output Current - A O ...

  • Page 36

    TPS54040A SLVSB58 – MARCH 2012 Power Dissipation Estimate The following formulas show how to estimate the IC power dissipation under continuous conduction mode (CCM) operation. These equations should not be used if the device is working in discontinuous conduction mode ...

  • Page 37

    Layout Layout is a critical portion of good power supply design. There are several signals paths that conduct fast changing currents or voltages that can interact with stray inductance or parasitic capacitance to generate noise or degrade the power ...

  • Page 38

    TPS54040A SLVSB58 – MARCH 2012 VIN VIN Cd GND EN SS/TR Css Figure 64. +24V to –12V Inverting Power Supply from SLVA317 Application Note 38 Submit Documentation Feedback + Cboot BOOT VSENSE COMP Rcomp ...

  • Page 39

    ... PACKAGING INFORMATION Orderable Device (1) Package Type Package Status TPS54040ADGQ ACTIVE MSOP- PowerPAD TPS54040ADGQR ACTIVE MSOP- PowerPAD TPS54040ADRCR ACTIVE SON TPS54040ADRCT ACTIVE SON (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. ...

  • Page 40

    ... TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Type Drawing TPS54040ADGQR MSOP- DGQ Power PAD TPS54040ADRCR SON DRC TPS54040ADRCT SON DRC PACKAGE MATERIALS INFORMATION Pins SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) 10 2500 330.0 12.4 5.3 10 3000 330.0 12 ...

  • Page 41

    ... Device Package Type TPS54040ADGQR MSOP-PowerPAD TPS54040ADRCR SON TPS54040ADRCT SON PACKAGE MATERIALS INFORMATION Package Drawing Pins SPQ Length (mm) DGQ 10 2500 DRC 10 3000 DRC 10 250 Pack Materials-Page 2 29-Mar-2012 Width (mm) Height (mm) 346.0 346.0 35.0 346.0 346.0 35.0 203.0 203.0 35.0 ...

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    Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the ...