Texas Instruments TPS2151 User manual

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March 2002 PMP Portable Power
User’s Guide
SLVU067

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. All products are sold subject to TI’s terms
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.
TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right,
copyright, mask work right, or other TI intellectual property right relating to any combination, machine, or process
in which TI products or services are used. Information published by TI regarding third–party products or services
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
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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:
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 2002, Texas Instruments Incorporated

EVM WARNINGS AND RESTRICTIONS
It is important to operate this EVM within the specified input and output ranges described 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
60°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 2002, Texas Instruments Incorporated

How to Use This Manual
v
Preface
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About This Manual
The TPS2151 is one of the four devices in the USB peripheral power
management family TPS2140/41/50/51, which integrates both an adjustable
linear low-drop voltage regulator (LDO) and a dual-current-limited power
switch. The dual-current-limit power switch is designed to eliminate inrush
current during power on.
The evaluation module (EVM) can help designers to evaluate the device with
several different configurations by manipulating only a couple of onboard
mechanical slide switches and a few jumpers.
Users need at least one dc voltage supply and a multimeter or oscilloscope to
evaluate the operation of the EVM.
How to Use This Manual
This document contains the following chapters:
-Chapter 1—Introduction
-Chapter 2—Schematic, Bill of Materials, Layout, and Setup
-Chapter 3—Changeable Components and Test Points

Information About Cautions and Warnings
vi
Information About Cautions and Warnings
This book may contain cautions and warnings.
This is an example of a caution statement.
A caution statement describes a situation that could potentially
damage your software or equipment.
This is an example of a warning statement.
A warning statement describes a situation that could potentially
cause harm to you.
The information in a caution or a warning is provided for your protection.
Please read each caution and warning carefully.

Contents
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1 Introduction 1-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 Schematic, Bill of Materials, Layout, and Setup 2-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.1 Schematic of the EVM 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.2 Bill of Materials 2-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.3 Layout of the EVM 2-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.4 Setup of the EVM 2-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3 Changeable Components and Test Points 3-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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2–1 Schematic of the TPS2151 Evaluation Module (EVM) 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–2 Top Layer of the EVM and Placement of the Components 2-5. . . . . . . . . . . . . . . . . . . . . . . . . .
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2–1 Bill of Materials of the TPS2151 EVM (SLVP202) 2-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3–1 Test Points and Test Signals 3-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-1
Introduction
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Each device in TPS2140/41/50/51 family integrates a dual-current-limiting
power switch and an adjustable low dropout regulator (LDO). Both the switch
and LDO limit inrush current by controlling the turnon slew rate and are
compatible with USB 1.0 and 2.0 Specifications.
The power switch has a unique dual-current-limiting function that limits the
current delivered to its load to less than 100 mA during power on. This feature
allows the load to utilize high-value capacitance at the output of the switch,
while keeping the inrush current low. When the output voltage from the switch
reaches about 93% of the input voltage, the switch power good output goes
high, and the switch current limit increases to 800 mA (minimum), at which
point higher current loads can be turned on. Therefore the load, other than
capacitance, on the switch output must not exceed the lower current limit (50
mA minimum) before the power good output rises to high.
Designers may activate the load by using either the power good signal or
another logic signal. The higher current limit provides short circuit protection
while allowing the load to draw maximum current from the source.
The switch and LDO function independently provides flexibility in many
applications requiring separate core and I/O voltages.
TPS2151 has a 5-V switch and an active high /SW_EN that distinguishes itself
from the other three parts (TPS2140, TPS2141, and TPS2150). For a detailed
description of functions and characteristics of the TPS2140/41/50/51, refer to
the data sheet (literature number SLVS399). You may check the data sheet
and ordering information on the Web site:
http://focus.ti.com/docs/prod/productfolder.jhtml?genericPartNumber=
TPS2151
To assist designers in the evaluation of the device, an evaluation module
(SLVP202) is offered based on TPS2151. The EVM requires 5-V supplies for
both the power switch and the LDO. The LDO output voltage is set to 3.3 V by
an external resistor divider. Two slide switches and few jumpers on the EVM
are provided to change the connections between the LDO and the power
switch, so several different application configurations can be evaluated.
The required external parts for the EVM are two input capacitors (on SW_IN
and LDO_IN), three output capacitors (on SW_OUT and LDO_OUT), and a
resistor divider (two resistors). All of these components are placed inside a
white-rectangle box on the EVM.
Chapter 1

2-1
Schematic, Bill of Materials, Layout, and Setup
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This chapter contains schematics, bill of materials, board layout, and setup of
EVM.
Topic Page
2.1 Schematic of the EVM 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.2 Bill of Materials 2-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.3 Layout of the EVM 2-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.4 Setup of the EVM 2-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 2

Schematic of the EVM
2-2
2.1 Schematic of the EVM
Figure 2–1 shows the schematic of the EVM.
Figure 2–1.Schematic of the TPS2151 Evaluation Module (EVM)
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