Texas Instruments TPS79301EVM User manual

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June 2002 Power Management Products Low Power
User’s Guide
SLVU060A

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
ordersandshouldverifythatsuchinformationiscurrentandcomplete.AllproductsaresoldsubjecttoTI’sterms
and conditions of sale supplied at the time of order acknowledgment.
TI warrants performance of its hardware products to the specifications applicable at the time of sale in
accordance with TI’s standard warranty. Testing and other quality control techniques are used to the extent TI
deems necessary to support this warranty. Except where mandated by government requirements, testing of all
parameters of each product is not necessarily performed.
TI assumes no liability for applications assistance or customer product design. Customers are responsible for
their products and applications using TI components. To minimize the risks associated with customer products
and applications, customers should provide adequate design and operating safeguards.
TIdoesnotwarrantorrepresentthatanylicense, eitherexpress orimplied, isgranted underanyTIpatentright,
copyright,maskworkright,orotherTIintellectualpropertyrightrelatingtoanycombination,machine,orprocess
inwhichTIproductsorservicesareused.InformationpublishedbyTIregardingthird–partyproductsorservices
does not constitute a license from TI to use such products or services or a warranty or endorsement thereof.
Use of such information may require a license from a third party under the patents or other intellectual property
of the third party, or a license from TI under the patents or other intellectual property of TI.
Reproduction of information in TI data books or data sheets is permissible only if reproduction is without
alteration and is accompanied by all associated warranties, conditions, limitations, and notices. Reproduction
of this information with alteration is an unfair and deceptive business practice. TI is not responsible or liable for
such altered documentation.
Resale of TI products or services with statements different from or beyond the parameters stated by TI for that
product or service voids all express and any implied warranties for the associated TI product or service and
is an unfair and deceptive business practice. TI is not responsible or liable for any such statements.
Mailing Address:
Texas Instruments
Post Office Box 655303
Dallas, Texas 75265
Copyright 2002, Texas Instruments Incorporated

EVM IMPORTANT NOTICE
Texas Instruments (TI) provides the enclosed product(s) under the following conditions:
Thisevaluationkit being soldbyTI is intendedforuse 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.
ShouldthisevaluationkitnotmeetthespecificationsindicatedintheEVMUser’sGuide,thekitmaybe 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,ORSTATUTORY,INCLUDINGANYWARRANTY OF MERCHANTABILITY ORFITNESSFORANY
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
receivedmaynotberegulatorycompliant oragency certified (FCC,UL, CE,etc.). Dueto theopen construction
oftheproduct,itistheuser’sresponsibilitytotakeanyandallappropriateprecautionswithregardtoelectrostatic
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’sGuidepriortohandlingtheproduct.Thisnoticecontainsimportantsafetyinformationabouttemperatures
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 2002, Texas Instruments Incorporated

DYNAMIC WARNINGS AND RESTRICTIONS
It is important to operate this EVM within the input voltage range of 2.7–5.5 V and the output
current range of 0 mA to 200 mA.
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.
Applyingloadsoutsideofthespecifiedoutputrangemayresultinunintendedoperationand/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.
Duringnormaloperation,somecircuitcomponentsmayhavecasetemperaturesgreaterthan
85°C.TheEVM isdesignedto operateproperlywith certaincomponentsabove 85°C aslong
astheinputandoutput rangesare maintained.Thesecomponentsincludebut arenot limited
tolinearregulators,switchingtransistors,passtransistors,andcurrentsenseresistors.These
typesof devicescanbeidentifiedusingtheEVM schematiclocated intheEVMUser’sGuide.
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 2002, Texas Instruments Incorporated

v
Read This First
Preface
About This Manual
This user’s guide describes the TPS793xxEVM LDO regulator evaluation
module (SLVP191). Each EVM package contains one SLVP191 test board,
with either a TPS79301DBV linear regulator or a TPS79328DBV linear
regulator,aswellassupportingpassivecomponents.TheSLVP191testboard
providesaconvenientmethodofevaluatingtheperformanceoftheTPS793xx
linear regulator family as well as other SOT–23 packaged linear regulators
with the same pinout.
How to Use This Manual
-Chapter 1—Introduction
-Chapter 2—EVM Test Setup
-Chapter 3—Test Results
Related Documentation From Texas Instruments
-TPS793xx data sheet (literature number SLVS348)

vi

Running Title—Attribute Reference
vii
Contents
Contents
1 Introduction 1-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.1 TPS793xx Family of LDO Regulators 1-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.2 EVM Design Strategy 1-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.3 Schematic 1-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.4 Bill of Materials 1-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.5 Board Layout 1-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 EVM Test Setup 2-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3 Test Results 3-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figures
1–1 TPS79301 Board Schematic 1-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1–2 TPS79328 Board Schematic 1-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1–3 Top Layer 1-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1–4 Bottom Layer 1-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1–5 Assembly Drawing—Top 1-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–1 Recommended TPS793xxEVM Test Setup 2-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3–1 Line Transient Response 3-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3–2 Ripple Rejection 3-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tables
1–1 SLVP191 Bill of Materials 1-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

viii

1-1
Introduction
This user’s guide describes the TPS793xxEVM LDO regulator evaluation
module (SLVP191). Each EVM package contains one SLVP191 test board,
with either a TPS79301DBV linear regulator or a TPS79328DBV linear
regulator, as well as supporting passive components.
Topic Page
1.1 TPS793xx Family of LDO Regulators 1–2. . . . . . . . . . . . . . . . . . . . . . . . . . .
1.2 EVM Design Strategy 1–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.3 Schematic 1–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.4 Bill of Materials 1–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.5 Board Layout 1–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 1

TPS793xx Family of LDO Regulators
1-2 Introduction
1.1 TPS793xx Family of LDO Regulators
Like all LDO linear regulators, the TPS793xx family of LDO regulators use a
series pass element and feedback network, including an error amplifier and
voltagereference, to providea regulated outputvoltage from aslightly higher,
possibly varying input voltage. However, these regulators have been
optimized to reduce ripple and noise on the output. For example, advanced
feedbackcompensationtechniqueswereusedtoincreasethebandwidthand
open loop gain of the feedback network while maintaining stability with any
2.2-µFceramiccapacitor.SincePSRRisdirectlyproportionaltothefrequency
response of the loop of the error amplifier, these regulators’higher loop gain
and larger bandwidth result in better PSRR over a wider range of frequencies
than standard regulators. In addition to circuit design optimization to reduce
circuitnoise,theprimarycontributortothenoiseofany regulator,thebandgap
reference, has been pinned out to allow further noise reduction through the
use of a filtering capacitor. Capabilities of this regulator include:
-200-mA load current
-TPS793xx family is available in 1.8-V, 2.5 V, 2.8 V, 2.85 V, 3.0 V, 3.3-V,
4.75-V, and adjustable with positive ENABLE.
-PSRR of 75 dB at 10 kHz
-Approximately 30-µV output noise
-Start-up in approximately 60 µs
-Excellent line and load transient responses
-Very low dropout voltage
-5-Pin SOT23 (DBV) package to minimize board space consumption
1.2 EVM Design Strategy
The purpose of this EVM is to facilitate evaluation of the TPS793xx family of
LDO regulators. Each EVM package contains one SLVP191 test board, with
either a TPS79301DBV linear regulator or a TPS79328DBV linear regulator,
as well as supporting passive components. The TPS79301DBV adjustable
device has been configured to provide 1.5-V output, and the TPS79328DBV
provides a 2.8-V output. The board’s small size and side clips facilitate
attaching it to other PCBs as a power module.
The board has additional passive components that can be configured to test
other SOT–23 packaged regulators with the same pin-out.