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User's Guide

SLUU420–MAY 2010

Using the TPS51217EVM-533, High-Performance,

Single-Synchronous Step-Down Controller for Notebook

Power Supply

The TPS51217EVM-533 evaluation module (EVM) uses the TPS51217, a small-size single buck controller

with adaptive on-time D-CAP™ providing dynamically selectable 0.9-V to 1.2-V output at up to 20 A from

input voltages ranging from 8 V to 20 V.

Contents

1 Description ................................................................................................................... 3

2 Electrical Performance Specifications .................................................................................... 3

3 Schematic .................................................................................................................... 4

4 Test Setup ................................................................................................................... 5

5 Test Procedure .............................................................................................................. 8

6 Performance and Typical Characteristic Curves ........................................................................ 9

7 EVM Assembly Drawing and PCB Layouts ............................................................................ 14

8 List of Materials ............................................................................................................ 16

9 References ................................................................................................................. 16

List of Figures

1 TPS51217EVM-533 Schematic .......................................................................................... 4

2 Tip and Barrel Measurement for Output Voltage Ripple............................................................... 5

3 Recommended Test Set Up ............................................................................................... 6

4 Efficiency at 0.9-V Output.................................................................................................. 9

5 Efficiency at 1.2-V Output.................................................................................................. 9

6 Load Regulation at 0.9-V Output.......................................................................................... 9

7 Load Regulation at 1.2-V Output.......................................................................................... 9

8 Line Regulation at 0.9-V Output ......................................................................................... 10

9 Line Regulation at 1.2-V Output ......................................................................................... 10

10 Load Transient 0.9-V Output............................................................................................. 10

11 Output Ripple at 0.9-V Output ........................................................................................... 11

12 Output Ripple at 1.2-V Output ........................................................................................... 11

13 Switching Node Waveform ............................................................................................... 11

14 Enable Turn-On Waveform at 0.9-V Output ........................................................................... 12

15 Enable Turn-Off Waveform at 0.9-V Output ........................................................................... 12

16 Pre-Bias Turn-On Waveform at 0.9-V Output ......................................................................... 12

17 Output Voltage Step-Down............................................................................................... 13

18 Output Voltage Step-Up .................................................................................................. 13

19 Top Layer Assembly Drawing (Top View).............................................................................. 14

20 Bottom Assembly Drawing (Bottom View) ............................................................................. 14

21 Top Copper (Top View)................................................................................................... 14

22 Internal Layer 1 (Top View) .............................................................................................. 14

23 Internal Layer 2 (Top View) .............................................................................................. 14

24 Bottom Copper (Top View)............................................................................................... 14

SLUU420–MAY 2010 Using the TPS51217EVM-533, High-Performance, Single-Synchronous

Step-Down Controller for Notebook Power Supply

Summary of content (19 pages)

PAGE 1
User's Guide SLUU420 – MAY 2010 Using the TPS51217EVM-533, High-Performance, Single-Synchronous Step-Down Controller for Notebook Power Supply The TPS51217EVM-533 evaluation module (EVM) uses the TPS51217, a small-size single buck controller with adaptive on-time D-CAP™ providing dynamically selectable 0.9-V to 1.2-V output at up to 20 A from input voltages ranging from 8 V to 20 V. 1 2 3 4 5 6 7 8 9 Contents Description ....................................................................................
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www.ti.com List of Tables 1 2 3 2 ................................................................ Test Point Functions ........................................................................................................ List of Materials ...........................................................................................................
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Description www.ti.com 1 Description The TPS51217EVM is designed to use a regulated voltage between 8 V and 20 V to produce dynamically selectable 0.9 V to 1.2 V output at up to 20 A of load current. The TPS51217EVM is designed to demonstrate the TPS51217 in a typical low-voltage application while providing a number of test points to evaluate the performance of the TPS51217. 1.1 Typical Applications • • • 1.
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Schematic Schematic + + + + 3 www.ti.com Figure 1.
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Test Setup www.ti.com 4 Test Setup 4.1 Test Equipment Connect test equipment and TPS51125AEVM board as shown in Section 4.2. 4.1.1 Voltage Source The input voltage source VIN should be a variable DC source between 0 V and 20 V capable of supplying 10 Adc. Connect VIN to J3 as shown in Figure 3. The input voltage source V5IN should be variable DC source between 0 V and 5.5 V capable of supplying 1 Adc. Connect V5IN to J1 and J2 as shown in Figure 3. 4.1.
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Test Setup 4.1.7 www.ti.com Recommended Wire Gauge For VIN to J3 (between 8 V and 20 V input) the recommended wire size is 1x AWG #14 per input connection, with the total length of wire less than 4 feet (2 feet input, 2 feet return). For J4 and J5 to LOAD the minimum recommended wire size is 2x AWG #14, with the total length of wire less than 4 feet (2 feet output, 2 feet return). 4.
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Test Setup www.ti.com 4.2.1 Input Connections 1. Prior to connecting the DC input source VIN and V5IN, it is advisable to limit the source current from VIN to 10 A and from V5IN to1A maximum. Make sure VIN and V5IN are initially set to 0 V and connected as shown in Figure 3. 2. Connect a voltmeter V1 at TP5 (VIN) and TP6 (VIN_GND) to measure the input voltage. 3. Connect a current meter A1 to measure the input current. 4.
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Test Procedure www.ti.com 5 Test Procedure 5.1 Line/Load Regulation and Efficiency Measurement Procedure 1. Ensure that the load is set to constant resistance mode and to sink 0 Adc. 2. Ensure that the SW1 switch on the EVM is at OFF position before VIN and V5IN are applied. 3. Increase VIN from 0 V to 8 V, using V1 to measure input voltage. 4. Increase V5IN from 0 V to 5, using V2 to measure input voltage. 5. Turn the SW1 switch to the ON position to enable the controller. 6. Input 0 V or 3.
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Performance and Typical Characteristic Curves www.ti.com 6 Performance and Typical Characteristic Curves Figure 4 through Figure 18 present typical performance curves for TPS51217EVM-533. 6.1 Efficiency 100 100 Auto-Skip VOUT = 0.9 V 90 90 80 80 VIN = 8 V VIN = 8 V 70 70 VIN = 12 V h - Efficiency - % h - Efficiency - % Auto-Skip VOUT = 1.2 V 60 VIN = 20 V 50 40 VIN = 12 V 60 50 40 30 30 20 20 10 10 0 0.001 0.01 0.1 1 10 IOUT - Output Current - A VIN = 20 V 0 0.
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Performance and Typical Characteristic Curves 6.3 www.ti.com Line Regulation 1.25 0.95 VOUT = 0.9 V 0.94 VOUT = 1.2 V 1.24 1.23 0.92 VOUT – Output Voltage – V VOUT – Output Voltage – V 0.93 IOUT = 20 A 1.22 IOUT = 20 A 1.21 0.91 1.20 0.90 1.19 0.89 0.88 1.18 IOUT = 0 A IOUT = 0 A 0.87 1.17 0.86 1.16 1.15 0.85 6 8 10 12 14 16 18 20 6 22 8 12 14 16 18 20 22 VIN – Input Voltage – V VIN – Input Voltage – V Figure 8. Line Regulation at 0.9-V Output 6.
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Performance and Typical Characteristic Curves www.ti.com 6.5 Output Ripple V IN = 12 V V OUT = 1.2 V IOUT = 20 A VIN = 12 V VOUT = 0.9 V IOUT = 20 A Figure 11. Output Ripple at 0.9-V Output 6.6 Figure 12. Output Ripple at 1.2-V Output Switch-Node Voltage VIN = 20 V VOUT = 0.9 V IOUT = 20 A Figure 13.
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Performance and Typical Characteristic Curves 6.7 www.ti.com Start and Stop Auto-Skip VIN = 12 V IOUT = 20 A EN (5 V/div) EN (5 V/div) Auto-Skip VIN = 12 V, IOUT = 0 A VOUT (0.5 V/div) VOUT (0.5 V/div) PGOOD (5 V/div) PGOOD (5 V/div) DRVL (5 V/div) t – Time – 500 ms/div t - Time - 10 ms/div Figure 14. Enable Turn-On Waveform at 0.9-V Output Figure 15. Enable Turn-Off Waveform at 0.9-V Output Auto-Skip VIN = 12 V, IOUT = 0 A EN (5 V/div) 0.5 V pre-biased VOUT (0.
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Performance and Typical Characteristic Curves www.ti.com 6.8 Dymamic Output Voltage Transitions VID1 (5 V/div) VID1 (5 V/div) VID0 (5 V/div) VID0 (5 V/div) VOUT (0.1 V/div) 1.2 V 1.2 V VOUT (0.1 V/div) 0.9 V 5V Auto-Skip VIN = 12 V IOUT = 0 A 0.9 V 5V PGOOD (5 V/div) Auto-Skip VIN = 12 V IOUT = 0 A t - Time - 1 ms/div t - Time - 1 ms/div Figure 17. Output Voltage Step-Down SLUU420 – MAY 2010 PGOOD (5 V/div) Figure 18.
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EVM Assembly Drawing and PCB Layouts 7 www.ti.com EVM Assembly Drawing and PCB Layouts Figure 19 through Figure 24 show the design of the TPS51217EVM-533 printed circuit board. The EVM has been designed using four layers, of 2-oz. copper circuit board. 14 Figure 19. Top Layer Assembly Drawing (Top View) Figure 20. Bottom Assembly Drawing (Bottom View) Figure 21. Top Copper (Top View) Figure 22.
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EVM Assembly Drawing and PCB Layouts www.ti.com Figure 23. Internal Layer 2 (Top View) SLUU420 – MAY 2010 Figure 24.
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List of Materials 8 www.ti.com List of Materials List of materials for the TPS51217EVM. Table 3. List of Materials REFDES QTY DESCRIPTION MFR PART NUMBER C1 1 Capacitor, ceramic, 4.7 nF, 50 V, X7R, 5%, 0603 STD STD C2, C8 2 Capacitor, ceramic, 0.
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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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EVALUATION BOARD/KIT/MODULE (EVM) WARNINGS, RESTRICTIONS AND DISCLAIMER (continued) Agreement to Defend, Indemnify and Hold Harmless. You agree to defend, indemnify and hold TI, its licensors and their representatives harmless from and against any and all claims, damages, losses, expenses, costs and liabilities (collectively, “Claims”) arising out of or in connection with any use of the EVM that is not in accordance with the terms of this agreement.
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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.