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User's Guide

SLVU444–March 2011

TPS54429EEVM-608, 4.5-A, SWIFT™ Regulator

Evaluation Module

This user’s guide contains background information for the TPS54429E as well as support documentation

for the TPS54429EEVM-608 evaluation module. Also included are the performance specifications,

schematic and the bill of materials for the TPS54429EEVM-608.

Contents

1 Introduction .................................................................................................................. 3

2 Performance Specification Summary ..................................................................................... 3

3 Modifications ................................................................................................................. 3

3.1 Output Voltage Setpoint ........................................................................................... 3

4 Test Setup and Results .................................................................................................... 4

4.1 Input / Output Connections ....................................................................................... 4

4.2 Start-Up Procedure ................................................................................................ 4

4.3 Efficiency ............................................................................................................ 5

4.4 Light Load Efficiency .............................................................................................. 5

4.5 Load Regulation .................................................................................................... 6

4.6 Line Regulation ..................................................................................................... 6

4.7 Load Transient Response ........................................................................................ 7

4.8 Output Voltage Ripple ............................................................................................. 7

4.9 Input Voltage Ripple ............................................................................................... 8

4.10 Start-Up ............................................................................................................. 8

4.11 Eco-mode™ Operation ............................................................................................ 9

5 Test Setup and Results .................................................................................................... 9

6 Board Layout ............................................................................................................... 11

6.1 Layout .............................................................................................................. 11

7 Schematic, Bill of Materials, and Reference ........................................................................... 15

7.1 Schematic ......................................................................................................... 15

7.2 Bill of Materials .................................................................................................... 15

7.3 Reference .......................................................................................................... 15

List of Figures

1 TPS54429EEVM-608 Efficiency .......................................................................................... 5

2 TPS54429EEVM-608 Light Load Efficiency............................................................................. 5

3 TPS54429EEVM-608 Load Regulation .................................................................................. 6

4 TPS54429EEVM-608 Line Regulation ................................................................................... 6

5 TPS54429EEVM-608 Load Transient Response....................................................................... 7

6 TPS54429EEVM-608 Output Voltage Ripple ........................................................................... 7

7 TPS54429EEVM-608 Input Voltage Ripple ............................................................................. 8

8 TPS54429EEVM-608 Start-Up............................................................................................ 8

9 TPS54429EEVM-608 Start-Up Relative to Enable ..................................................................... 9

10 TPS54329EEVM-608 Normal Switching................................................................................. 9

11 TPS54429EEVM-608 Entering Eco-mode™ Operation.............................................................. 10

12 TPS54429EEVM-608 Fully in Eco-mode™ Operation ............................................................... 10

SWIFT, Eco-mode, D-CAP2 are trademarks of Texas Instruments.

SLVU444–March 2011 TPS54429EEVM-608, 4.5-A, SWIFT™ Regulator— Evaluation Module

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Summary of content (17 pages)

PAGE 1
User's Guide SLVU444 – March 2011 TPS54429EEVM-608, 4.5-A, SWIFT™ Regulator Evaluation Module This user’s guide contains background information for the TPS54429E as well as support documentation for the TPS54429EEVM-608 evaluation module. Also included are the performance specifications, schematic and the bill of materials for the TPS54429EEVM-608. 1 2 3 4 5 6 7 Contents Introduction ..................................................................................................................
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www.ti.com 13 Top Assembly .............................................................................................................. 11 14 Top Layer ................................................................................................................... 12 15 Internal Layer 1 ............................................................................................................ 12 16 Internal Layer 2 ...............................................................................
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Introduction www.ti.com 1 Introduction The TPS54429E is a single, adaptive on-time D-CAP2™ mode synchronous buck converter requiring a very low external component count. The D-CAP2™ control circuit is optimized for low-ESR output capacitors such as POSCAP, SP-CAP or ceramic types and features fast transient response with no external compensation. The switching frequency is internally set at a nominal 700 kHz.
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Test Setup and Results www.ti.com Table 3 lists the R1 value for some common output voltages. For higher output voltages of 1.8 V or above, a feedforward capacitor (C2) may be required to improve phase margin and is recommended for auto skip Eco-mode™ stability. Pads for this component (C2) are provided on the printed-circuit board. Note that the values given in Table 3 are standard values and not the exact value calculated using Table 3. Table 3.
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Test Setup and Results www.ti.com 4.3 Efficiency Figure 1 shows the efficiency for the TPS54429EEVM-608 at an ambient temperature of 25°C. The input voltage is 12 V. 100 90 80 Efficiecny - % 70 60 50 40 30 20 10 0 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 Output Current - A Figure 1. TPS54429EEVM-608 Efficiency 4.4 Light Load Efficiency Figure 2 shows the efficiency at light loads for the TPS54429EEVM-608 at an ambient temperature of 25°C. The input voltage is 12 V.
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Test Setup and Results 4.5 www.ti.com Load Regulation The load regulation for the TPS54429EEVM-608 is shown Figure 3. The input voltage is 12 V. 2 1.5 Output Voltage Deviation - % 1 0.5 0 -0.5 -1 -1.5 -2 0 0.5 1 1.5 2 2.5 Output Current - A 3 3.5 4 4.5 Figure 3. TPS54429EEVM-608 Load Regulation 4.6 Line Regulation The line regulation for the TPS54429EEVM-608 is shown Figure 4. the load current is 2.25 A. 0.5 0.4 Output Voltage Deviation - % 0.3 0.2 0.1 0 -0.1 -0.2 -0.3 -0.
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Test Setup and Results www.ti.com 4.7 Load Transient Response The TPS54429EEVM-608 response to load transient is shown in Figure 5. The current step is from 1.25 A to 3.25 A. Total peak-to-peak output voltage variation is as shown. VOUT = 20 mV / div (dc coupled, -1.013 V offset) IOUT = 2 A / div Load step = 1.25 to 3.25 A Slew rate = 100 mA / µsec Time = 100 µsec / div Figure 5. TPS54429EEVM-608 Load Transient Response 4.
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Test Setup and Results 4.9 www.ti.com Input Voltage Ripple The TPS54429EEVM-608 input voltage ripple is shown in Figure 7. The output current is the rated full load of 4.5 A. VIN = 100 mV / div (ac coupled) PH = 5 V / div Time = 500 nsec / div Figure 7. TPS54429EEVM-608 Input Voltage Ripple 4.10 Start-Up The TPS54429EEVM-608 start-up waveform relative to VIN is shown in Figure 8. VIN = 5 V / div VOUT = 500 mV / div Time = 2 msec / div Figure 8. TPS54429EEVM-608 Start-Up 8 TPS54429EEVM-608, 4.
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Test Setup and Results www.ti.com The TPS54429EEVM-608 start-up waveform relative to enable (EN) is shown in Figure 9. 4.11 Eco-mode™ Operation The waveforms Figure 10, Figure 11 and Figure 12in show the Eco-mode™ operation of the TPS54429E. In Figure 10, the circuit is switching normally with the inductor current always positive. 5 Test Setup and Results VIN = 5 V / div EN = 10 V / div VOUT = 1 V / div Time = 2 msec / div Figure 9.
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Test Setup and Results www.ti.com When the inductor current falls to zero, Eco-mode™ operation begins. The TPS54329E enters a power-saving skip mode. Switching resumes when the fedback voltage at VFB falls below an internally set threshold. Figure 11 shows the switching activity as the circuit is just entering Eco-mode™ operation. The effective switching period increases slightly as the pulse-skipping time is short. In Figure 12, the load current is reduced further, and the skip time is longer.
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Board Layout www.ti.com 6 Board Layout This section provides description of the TPS54429EEVM-608, board layout, and layer illustrations. 6.1 Layout The board layout for the TPS54429EEVM-608 and is shown in Figure 13 through Figure 18. The top layer contains the main power traces for VIN, VO, and ground. Also on the top layer are connections for the pins of the TPS54429E and a large area filled with ground. Most of the signal traces are also located on the top side.
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Board Layout www.ti.com Figure 14. Top Layer Figure 15. Internal Layer 1 12 TPS54429EEVM-608, 4.
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Board Layout www.ti.com Figure 16. Internal Layer 2 Figure 17. Bottom Layer as Seen From Back Side SLVU444 – March 2011 Submit Documentation Feedback TPS54429EEVM-608, 4.
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Board Layout www.ti.com Figure 18. Bottom Assembly as Seen From Back Side 14 TPS54429EEVM-608, 4.
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Schematic, Bill of Materials, and Reference www.ti.com 7 Schematic, Bill of Materials, and Reference This section presents the TPS54429EEVM-608 schematic, bill of materials, and reference. 7.1 Schematic Figure 19 is the schematic for the TPS54429EEVM. Figure 19. TPS54429EEVM-608 Schematic Diagram 7.2 Bill of Materials Table 5.
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Evaluation Board/Kit Important Notice Texas Instruments (TI) provides the enclosed product(s) under the following conditions: This evaluation board/kit is intended for use for ENGINEERING DEVELOPMENT, DEMONSTRATION, OR EVALUATION PURPOSES ONLY and is not considered by TI to be a finished end-product fit for general consumer use. Persons handling the product(s) must have electronics training and observe good engineering practice standards.
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IMPORTANT NOTICE 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 latest relevant information before placing orders and should verify that such information is current and complete.