Texas Instruments TPS54980EVM-022 User manual

 
E
! "
September 2003 PMP Systems Power
User’s Guide
SLVU090

IMPORTANT NOTICE
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Mailing Address: Texas Instruments
Post Office Box 655303 Dallas, Texas 75265
Copyright 2003, Texas Instruments Incorporated

EVM IMPORTANT NOTICE
Texas Instruments (TI) provides the enclosed product(s) under the following conditions:
This evaluation kit being sold by TI is intended for use for ENGINEERING DEVELOPMENT OR EVALUATION
PURPOSES ONLY and is not considered by TI to be fit for commercial use. As such, the goods being provided
may not be complete in terms of required design-, marketing-, and/or manufacturing-related protective
considerations, including product safety measures typically found in the end product incorporating the goods.
As a prototype, this product does not fall within the scope of the European Union directive on electromagnetic
compatibility and therefore may not meet the technical requirements of the directive.
Should this evaluation kit not meet the specifications indicated in the EVM User’s Guide, the kit may be returned
within 30 days from the date of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE
WARRANTY MADE BY SELLER TO BUYER AND IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED,
IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR ANY
PARTICULAR PURPOSE.
The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user
indemnifies TI from all claims arising from the handling or use of the goods. Please be aware that the products
received may not be regulatory compliant or agency certified (FCC, UL, CE, etc.). Due to the open construction
of the product, it is the user’s responsibility to take any and all appropriate precautions with regard to electrostatic
discharge.
EXCEPT TO THE EXTENT OF THE INDEMNITY SET FORTH ABOVE, NEITHER PARTY SHALL BE LIABLE
TO THE OTHER FOR ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES.
TI currently deals with a variety of customers for products, and therefore our arrangement with the user is not
exclusive.
TI assumes no liability for applications assistance, customer product design, software performance, or
infringement of patents or services described herein.
Please read the EVM User’s Guide and, specifically, the EVM Warnings and Restrictions notice in the EVM
User’s Guide prior to handling the product. This notice contains important safety information about temperatures
and voltages. For further safety concerns, please contact the TI application engineer.
Persons handling the product must have electronics training and observe good laboratory practice standards.
No license is granted under any patent right or other intellectual property right of TI covering or relating to any
machine, process, or combination in which such TI products or services might be or are used.
Mailing Address:
Texas Instruments
Post Office Box 655303
Dallas, Texas 75265
Copyright 2003, Texas Instruments Incorporated

EVM WARNINGS AND RESTRICTIONS
It is important to operate this EVM within the input and output voltage ranges specified in the
EVM User’s Guide.
Exceeding the specified input range may cause unexpected operation and/or irreversible
damage to the EVM. If there are questions concerning the input range, please contact a TI
field representative prior to connecting the input power.
Applying loads outside of the specified output range may result in unintended operation and/or
possible permanent damage to the EVM. Please consult the EVM User’s Guide prior to
connecting any load to the EVM output. If there is uncertainty as to the load specification,
please contact a TI field representative.
During normal operation, some circuit components may have case temperatures greater than
55°C. The EVM is designed to operate properly with certain components above 60°C as long
as the input and output ranges are maintained. These components include but are not limited
to linear regulators, switching transistors, pass transistors, and current sense resistors. These
types of devices can be identified using the EVM schematic located in the EVM User’s Guide.
When placing measurement probes near these devices during operation, please be aware
that these devices may be very warm to the touch.
Mailing Address:
Texas Instruments
Post Office Box 655303
Dallas, Texas 75265
Copyright 2003, Texas Instruments Incorporated

-1
Contents
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1 Introduction 1-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.1 Background 1-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.2 Performance Specification Summary 1-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.3 Modifications 1-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.3.1 Changing Output Voltage 1-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.3.2 Switching Frequency 1-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.3.3 Power Sequencing 1-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 Test Setup and Results 2-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.1 Input/Output Connections 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.2 Efficiency 2-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.3 Power Dissipation 2-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.4 Output Voltage Regulation 2-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.5 Load Transients 2-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.6 Loop Characteristics 2-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.7 Output Voltage Ripple 2-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.8 Input Voltage Ripple 2-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.9 Power Up and Down 2-9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3 Board Layout 3-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.1 Layout 3-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4 Schematic and Bill of Materials 4-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.1 Schematic 4-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.2 Bill of Materials 4-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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
1−1 Frequency Trimming Resistor Selection Graph 1-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2−1 Connection Diagram 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2−2 Measured Efficiency, TPS54980 2-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2−3 Measured Circuit Losses 2-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2−4 Load Regulation 2-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2−5 Line Regulation 2-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2−6 Load Transient Response, TPS54980 2-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2−7 Measured Loop Response, TPS54980, VI= 3 V 2-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2−8 Measured Loop Response, TPS54980, VI= 4 V 2-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2−9 Measured Output Voltage Ripple, TPS54980 2-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2−10 Input Voltage Ripple, TPS54980 2-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2−11 Power Up with Tracking 2-9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2−12 Power Down With Tracking 2-10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2−13 Power Up With Ratiometric Sequencing 2-10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2−14 Power Down With Ratiometric Sequencing 2-11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2−15 Power Up With Core Voltage Rising First 2-11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2−16 Power Up With Core Voltage Falling Second 2-12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3−1 Top-Side Layout 3-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3−2 Internal Layer 2 3-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3−3 Internal Layer 3 3-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3−4 Bottom Side Layout (looking from top side) 3-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3−5 Top Side Assembly 3-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4−1 TPS54980EVM-022 Schematic 4-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1−1 Input Voltage and Output Current Summary 1-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−2 TPS54980EVM-022 Performance Specification Summary 1-3. . . . . . . . . . . . . . . . . . . . . . . . . .
1−3 Output Voltage Programming 1-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4−1 TPS54980EVM-022 Bill of Materials 4-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Read This First
Preface

About This Manual
This user’s guide describes the characteristics, operation, and the use of the
TPS54980EVM-022 evaluation module. It covers all pertinent areas involved
to properly use this EVM board along with the devices that it supports. The
physical PCB layout, schematic diagram, and circuit descriptions are included.
How to Use This Manual
This document contains the following chapters:
-Chapter 1—Introduction
-Chapter 2—Test Setup and Results
-Chapter 3—Board Layout
-Chapter 4—Schematic and Bill of Materials
FCC Warning
This equipment is intended for use in a laboratory test environment only. It gen-
erates, uses, and can radiate radio frequency energy and has not been tested
for compliance with the limits of computing devices pursuant to subpart J of
part 15 of FCC rules, which are designed to provide reasonable protection
against radio frequency interference. Operation of this equipment in other en-
vironments may cause interference with radio communications, in which case
the user at his own expense will be required to take whatever measures may
be required to correct this interference.
Trademarks
-SWIFT and PowerPAD are trademarks of Texas Instruments.

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1-1
Introduction

This chapter contains background information for the TPS54980 as well as
support documentation for the TPS54980EVM-022 evaluation module
(HPA022). The TPS54980EVM-022 performance specifications are given, as
well as modifications.
Topic Page
1.1 Background 1-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.2 Performance Specification Summary 1-3. . . . . . . . . . . . . . . . . . . . . . . . . . .
1.3 Modifications 1-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 1

Background
1-2
1.1 Background
The TPS54980 tracking dc/dc converter is designed to provide accurate
power sequencing in applications where two or more voltages are required for
a load. These types of applications include core and I/O power supplies for
microprosessors, DSPs, and FPGAs. Typically, some specific relation
between the core and I/O supply voltages has to be provided during the power
up and power down sequences. The TPS54980 tracking dc/dc converter is
capable of direct tracking, ratiometric tracking, and voltage sequencing with
a second power source.
The TPS54980EVM−022 is a two-channel EVM demonstrating the flexibility
inherent in the TPS54980 design for tracking and sequencing core and I/O
voltages. The TPS54980 is used to generate the core voltage and is nominally
set at 1.8 V. The nominal 3.3-V I/O voltage is provided by a TPS2013
distribution switch. Rated input voltage and output current range are listed in
Table 1−1.
Table 1−1.Input Voltage and Output Current Summary
EVM Input Voltage Range Output Current Range
TPS54980EVM−022
3.0 V to 4.0 V
Core, −9 A to 9 A
TPS54980EVM−022
3.0 V to 4.0 V
I/O, 0 to 1.5 A
This evaluation module is designed to demonstrate the small PCB areas that
may be achieved when designing with the TPS54980 regulator. The switching
frequency is set at a nominal 700 kHz, allowing the use of a small footprint
0.65-µH output inductor.
The MOSFETs of the TPS54980 are incorporated inside the TPS54980
package. This eliminates the need for external MOSFETs and their associated
drivers. The low drain-to-source on resistance of the MOSFETs provides the
TPS54980 high efficiency and helps to keep the junction temperature low at
high output currents.The compensation components are provided external to
the IC and allow for an adjustable output voltage and a customizable loop
response.
The TPS54980 device uses the TRACKIN pin to access the tracking and
sequencing capabilities. An internal multiplexer circuit compares the voltage
at this pin with the internal reference voltage and uses the lesser of the two as
the reference for the output voltage regulation. When the output of another
power supply or distribution switch is connected to the TRACKIN pin of the
TPS54980, the output of the TPS54980 tracks the output of this other channel
during power up or power down, until the voltage at the TRACKIN pin becomes
higher than the internal reference voltage. By applying the other power supply
output to the TRACKIN pin through an appropriate resistor divider network,
any required power up and power down relation between the two output
voltages of the regulators can be set by changing the ratio of the divider
network.