Texas Instruments | Simple Power Solution Using LDOs for the DM365 (Rev. A) | Application notes | Texas Instruments Simple Power Solution Using LDOs for the DM365 (Rev. A) Application notes

Texas Instruments Simple Power Solution Using LDOs for the DM365 (Rev. A) Application notes
Application Report
SLVA355A – August 2009 – Revised August 2009
Simple Power Solution Using LDOs for the DM365
Ambreesh Tripathi .......................................................................... PMP - DC/DC Low Power Converters
ABSTRACT
This reference design is intended for users designing with TMS320DM365 Processor.
This design is ideal for achieving the requirement of a input voltage of 5V, and uses
LDOs for a simple, small configuration.
1
2
3
4
5
Contents
Introduction ..........................................................................................
Power Requirements ...............................................................................
Features .............................................................................................
List of Material ......................................................................................
Test Result ..........................................................................................
1
2
2
4
5
List of Figures
1
2
PMP5048 Reference Design Schematic ........................................................ 3
Shows Sequencing in Start up Waveform ....................................................... 5
List of Tables
1
2
1
TMS320DM365 Power Specs .................................................................... 2
PMP5048 List of Materials ........................................................................ 4
Introduction
In dual voltage architectures, coordinated management of power supplies is necessary to avoid potential
problems and ensure reliable performance. Power supply designers must consider the timing and voltage
differences between core and I/O voltage supplies during power up and power down operations.
Sequencing refers to the order, timing and differential in which the two voltage rails are powered up and
down. A system designed without proper sequencing may be at risk for two types of failures. The first of
these represents a threat to the long term reliability of the dual voltage device, while the second is more
immediate, with the possibility of damaging interface circuits in the processor or system devices such as
memory, logic or data converter ICs.
Another potential problem with improper supply sequencing is bus contention. Bus contention is a
condition when the processor and another device both attempt to control a bi-directional bus during power
up. Bus contention may also affect I/O reliability. Power supply designers should check the requirements
regarding bus contention for individual devices.
SLVA355A – August 2009 – Revised August 2009
Submit Documentation Feedback
Simple Power Solution Using LDOs for the DM365
1
Power Requirements
2
www.ti.com
Power Requirements
The power specifications and sequencing requirements for TMS320DM365 Processor is shown in the
table below.
Table 1. TMS320DM365 Power Specs
Voltage
(V)
Imax
(mA)
Tolerance
Sequencing
Order
1.2 *
650
±5%
1
VDDS18, VDD18_PRTCSS, VDDMXI, VDD18_SLDO,
VDD18_DDR, VDDA18_PLL, VDDA18_USB, VDDA18_VC,
VDDA18_ADC, VDDA18_DAC
1.8
95
±5%
2
VDDS33, VDDA33_USB, VDDA33_VC
3.3
51
±5%
3
±5%
Ramp with
appropriate
voltage
Pin Name
Core
I/O
I/O
I/O
CVDD, VDD12_PRTCSS, VDDA12_DAC, VPP
VDD_AEMIF1_18_3 3, VDD_AEMIF2_18_3 3, VDD_ISIF18_33
1.8 / 3.3
65
Note:
• If running DM365 @ 300MHz, then CVDD, VDD12_PRTCSS, VDDA12_DAC and VPP = 1.35V and Imax = 800mA.
• If using PRTCSS, power-up sequencing changes to:
1.
2.
3.
4.
5.
3
Power on
Power on
Power on
Power on
Power on
PRTCSS core (1.2-V) while RESET is low
PRTCSS I/O (1.8-V)
Main core (1.2-V)
Main I/O (1.8-V)
Main/Analog I/O (3.3-V)
Features
The design uses the following LDSOs.
Devices:
TPS74701(3.3V),TPS74801(1.2V),TPS74701(1.8V)
Power supply specs:
Vin
5 V ± 10%
Vout1
1.2 V ± 5% at 800 mA
Vout2
1.8 V ± 5% at 200 mA
Vout3
3.3 V ± 5% at 200 mA
Sequencing
1) Vout1
2) Vout2
3) Vout3
TPS74801 and TPS74701
• VOUT Range: 0.8V to 3.6V
• 2% Accuracy Over Line/Load/Temperature
• Programmable Soft-Start Provides Linear Voltage Startup
• Stable with Any Output Capacitor ≥ 2.2µF
• Available in a Small 3mm × 3mm × 1mm SON-10 and 5 × 5 QFN-20 Packages
More information on the Devices can be found from the datasheets.
TPS74801 –SBVS074F
TPS74701 –SBVS099D
2
Simple Power Solution Using LDOs for the DM365
SLVA355A – August 2009 – Revised August 2009
Submit Documentation Feedback
Features
www.ti.com
Figure 1. PMP5048 Reference Design Schematic
Proper sequencing is achieved in the design with the use of enable pins. The Core 1.2V at 800mA
(TPS74801) comes first, PG output of the device then enable the TPS74701 (1.8V) device which in turn
enable second TPS74701 (3.3V) device thus, follwoing the required sequence.
SLVA355A – August 2009 – Revised August 2009
Submit Documentation Feedback
Simple Power Solution Using LDOs for the DM365
3
List of Material
4
www.ti.com
List of Material
Table 2. PMP5048 List of Materials
Count
RefDes
Value
Description
Size
Part Number
MFR
Area
1
C1
1.0 µF
Capacitor, Ceramic, 25V, X5R, 10%
0603
C1608X5R1E105K
TDK
5650
1
C2
4.7 µF
Capacitor, Ceramic, 6.3V, X5R, 10%
0603
C1608X5R0J106M
TDK
5650
1
C3
4.7 µF
Capacitor, Ceramic, 6.3V, X5R, 10%
0603
C1608X5R0J475K
TDK
5650
6
C4
4.7 µF
Capacitor, Ceramic,4.7 µF, 6.3V, X5R
0603
C1608X5R0J475M
TDK
5650
2
C5
1 µF
Capacitor, Ceramic,1 µF, 16V, X5R
0603
C1608X5R1C105K
TDK
5650
C6
4.7 µF
Capacitor, Ceramic,4.7 µF, 6.3V, X5R
0603
C1608X5R0J475M
TDK
5650
C7
4.7 µF
Capacitor, Ceramic,4.7 µF, 6.3V, X5R
0603
C1608X5R0J475M
TDK
5650
C8
1 nF
Capacitor, Ceramic, 1000 pF, 50V, X7R, 10%
0603
C1608X7R1H102K
TDK
5650
C9
4.7 µF
Capacitor, Ceramic,4.7 µF, 6.3V, X5R
0603
C1608X5R0J475M
TDK
5650
C10
1 µF
Capacitor, Ceramic,1 µF, 16V, X5R
0603
C1608X5R1C105K
TDK
5650
C11
4.7 µF
Capacitor, Ceramic,4.7 µF, 6.3V, X5R
0603
C1608X5R0J475M
TDK
5650
C12
4.7 µF
Capacitor, Ceramic,4.7 µF, 6.3V, X5R
0603
C1608X5R0J475M
TDK
5650
C13
1 nF
Capacitor, Ceramic, 1000 pF, 50V, X7R, 10%
0603
C1608X7R1H102K
TDK
5650
2
1
J1
PEC36SAAN
Header, Male 4-pin, 100mil spacing, (36-pin strip)
0.100 inch x 4
PEC36SAAN
Sullins
50000
1
R1
2.49k
Resistor, Chip, 1/16W, 1%
0603
Std
Std
5650
1
R2
4.99k
Resistor, Chip, 1/16W, 1%
0603
Std
Std
5650
1
R3
10.0k
Resistor, Chip, 1/16W, 1%
0603
Std
Std
5650
2
R4
10k
Resistor, Chip, 10kΩ 1/16W, 5%
0603
Std
Std
5,650
1
R5
4.99k
Resistor, Chip, 2k49Ω, 1/16W, 5%
0603
Std
Std
5,650
1
R6
4.02k
Resistor, Chip, 4k99Ω, 1/16W, 5%
0603
Std
Std
5,650
R7
10k
Resistor, Chip, 10kΩ 1/16W, 5%
0603
Std
Std
5,650
1
R8
15.6k
Resistor, Chip, 2k49Ω, 1/16W, 5%
0603
Std
Std
5,650
1
R9
4.99k
Resistor, Chip, 4k99Ω, 1/16W, 5%
0603
Std
Std
5,650
1
U1
TPS74801DRC
IC, 1.5A LDO Regulator with Soft-Start
SON-10
TPS74801DRC
TI
30400
2
U2
TPS74701DRC
IC, 1.5A LDO Regulator with Soft-Start
SON-10
TPS74701DRC
TI
30400
U3
TPS74701DRC
IC, 1.5A LDO Regulator with Soft-Start
SON-10
TPS74701DRC
TI
30400
Notes: 1. These assemblies are ESD sensitive, ESD precautions shall be observed.
2. These assemblies must be clean and free from flux and all contaminants.
Use of no clean flux is not acceptable.
3. These assemblies must comply with workmanship standards IPC-A-610 Class 2.
4. Ref designators marked with an asterisk ('**') cannot be substituted.
All other components can be substituted with equivalent MFG's components.
4
Simple Power Solution Using LDOs for the DM365
SLVA355A – August 2009 – Revised August 2009
Submit Documentation Feedback
Test Result
www.ti.com
5
Test Result
The startup waveform, shown in Figure 2 , demonstrates that the required sequencing order is followed.
Figure 2. Shows Sequencing in Start up Waveform
SLVA355A – August 2009 – Revised August 2009
Submit Documentation Feedback
Simple Power Solution Using LDOs for the DM365
5
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 TI 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. Information of third parties may be subject to additional
restrictions.
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.
TI products are not authorized for use in safety-critical applications (such as life support) where a failure of the TI product would reasonably
be expected to cause severe personal injury or death, unless officers of the parties have executed an agreement specifically governing
such use. Buyers represent that they have all necessary expertise in the safety and regulatory ramifications of their applications, and
acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning their products
and any use of TI products in such safety-critical applications, notwithstanding any applications-related information or support that may be
provided by TI. Further, Buyers must fully indemnify TI and its representatives against any damages arising out of the use of TI products in
such safety-critical applications.
TI products are neither designed nor intended for use in military/aerospace applications or environments unless the TI products are
specifically designated by TI as military-grade or "enhanced plastic." Only products designated by TI as military-grade meet military
specifications. Buyers acknowledge and agree that any such use of TI products which TI has not designated as military-grade is solely at
the Buyer's risk, and that they are solely responsible for compliance with all legal and regulatory requirements in connection with such use.
TI products are neither designed nor intended for use in automotive applications or environments unless the specific TI products are
designated by TI as compliant with ISO/TS 16949 requirements. Buyers acknowledge and agree that, if they use any non-designated
products in automotive applications, TI will not be responsible for any failure to meet such requirements.
Following are URLs where you can obtain information on other Texas Instruments products and application solutions:
Products
Amplifiers
Data Converters
DLP® Products
DSP
Clocks and Timers
Interface
Logic
Power Mgmt
Microcontrollers
RFID
RF/IF and ZigBee® Solutions
amplifier.ti.com
dataconverter.ti.com
www.dlp.com
dsp.ti.com
www.ti.com/clocks
interface.ti.com
logic.ti.com
power.ti.com
microcontroller.ti.com
www.ti-rfid.com
www.ti.com/lprf
Applications
Audio
Automotive
Broadband
Digital Control
Medical
Military
Optical Networking
Security
Telephony
Video & Imaging
Wireless
www.ti.com/audio
www.ti.com/automotive
www.ti.com/broadband
www.ti.com/digitalcontrol
www.ti.com/medical
www.ti.com/military
www.ti.com/opticalnetwork
www.ti.com/security
www.ti.com/telephony
www.ti.com/video
www.ti.com/wireless
Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265
Copyright © 2009, Texas Instruments Incorporated
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Related manuals

Download PDF

advertising