ROHM’s Online Tool
ROHM LDO Finder
User's Guide
● Table of Contents
1. What is ROHM LDO Finder?
1.1
1.2
1.3
1.4
1.5
Outline
Default language
Applicable products
Notes
Questions/Comments
2. Access Method
2.1
From ROHM’s homepage (http://www.rohm.com)
3. Usage Instructions
3.1
Enter the user conditions at "Entrance"
3.2
Setting parameters (parametric search)
3.2.1
Select Channel, Grade and Functions
3.2.2
Enter more detail user conditions
3.2.3
Select products (up to 6 products)
3.2.4
Click "Agree Disclaimer & Show Graph" (after reading Disclaimer carefully)
3.2.5
Reset setting conditions
3.3
Checking the results
3.3.1
Radio button in "Graph"
3.3.2
Radio button in "Display"
3.3.3
Input box in "Axis"
3.3.4
Calculation of Junction temperature (Tj) and maximum power dissipation (Pd(max)) (based on θja)
3.3.5
Download PDF (screenshot)
www.rohm.com
© 2016 ROHM Co., Ltd. All rights reserved.
1/10
2016.02 - Rev.001
Design Support Document
ROHM LDO Finder User’s Guide
1. What is ROHM LDO Finder?
1.1 Outline
ROHM LDO Finder is an online tool that allow circuit designers searching for an IC of Linear regulator to easily find a
uitable Linear regulator.
ROHM LDO Finder can compare "IOUT vs. VOUT" graph (means OCP) and minimum dropout voltage (means Vdrop) to up to
six products simultaneously. In addition, it implements simple calculation to display Junction temperature(Tj) and Power
dissipation(Pd) on the required conditions.
VOUT
ROHM LDO Finder
Input
IOUT
VIN
Ta
Output
User
1/xxx
Pd
0.6
0.5
Vdrop (V)
0.4
6.000
5.000
4.000
0.3
0.2
12V -40℃
0.1
V out [ V]
12V 25℃
3.000
0
12V 125℃
0
Now(12V 75℃)
0.5
1
Iout(A)
1.5
2
2.000
Tj
Typical ref erence data
1.000
0.000
0.000
0.200
0.400
0.600
0.800
1.000
1.200
1.400
Iout [A]
OCP/Vdrop reference data
(at required temperature)
1.2
PKG
size
Default Language
The default language of ROHM LDO Finder is English. Only the MyROHM user registration and user authentication
screens can be displayed in other languages (i.e. Japanese).
1.3
Applicable Products
- Single-Output LDO Regulators
- Standard Voltage Regulators
- ROHM LDO Finder will continue adding new products and series
1.4
Notes
- The results provided by ROHM LDO Finder are based on experimental results using ROHM evaluation boards and cannot be
- guaranteed. In addition, the results by ROHM LDO Finder offers reference results, not guaranteed results.
- ROHM LDO Finder specifications are subject to change without notice.
1.5
Questions/Comments
For inquiries and/or comments, please contact us at: https://www.rohm.com/web/global/contactus
www.rohm.com
© 2016 ROHM Co., Ltd. All rights reserved.
2/10
2016.02 - Rev.001
Design Support Document
ROHM LDO Finder User’s Guide
2. Access Method
ROHM LDO Finder can be accessed using as follow:
- From ROHM’s homepage (http://www.rohm.com) (2.1)
2.1
From ROHM’s homepage (http://www.rohm.com)
■ Homepage
Power Management
■ ROHM LDO Finder's "Entrance"
(http://www.rohm.com/web/global/groups/-/group/groupname/Power%20Management)
enter conditions
LINEAR REGULATOR
www.rohm.com
© 2016 ROHM Co., Ltd. All rights reserved.
3/10
2016.02 - Rev.001
Design Support Document
ROHM LDO Finder User’s Guide
3. Usage Instructions
3.1
Enter the user conditions at "Entrance"
Start ROHM LDO Finder as described on page 3.
3.2
Setting parameters (parametric search)
The basic design flow is as follow (with some possible omissions of intervening steps)
ROHM
LDO Finder
STEP 0
STEP 1
STEP 2
input
parameters
(entrance)
fill out
parameters
and check
select
products
up to 6
Basic operation
STEP 3
Click "Agree
Disclaimer and
Show Graph"
STEP 4
STEP 5
Verify
results
Click
"Download
PDF"
As required
STEP 1
3.2.1
Select Channel, Grade and Functions
Check the boxes you required. After having checked it, parametric search works.
www.rohm.com
© 2016 ROHM Co., Ltd. All rights reserved.
4/10
2016.02 - Rev.001
Design Support Document
ROHM LDO Finder User’s Guide
3.2.2
Enter more detail required conditions
Enter the following parameters,
: narrowing by recommended operating input voltage range
VIN
("Typ" is used after the "Agree Disclaimer & Show Graph")
VOUT : narrowing by required output voltage
IOUT : narrowing by recommended maximum output current range
Ta
: narrowing by recommended operating temperature
(This is used on calculation of junction temperature (Tj) and maximum power dissipation (Pd(max))
based on θja)
After entering the above parameters, parametric search works.
STEP 2
3.2.3
Select products (up to 6 products)
After narrowing products by input parameters and select functions, please check the box of products you'd like to
compare to characteristic.
You can select up to 6 products. After selecting it, a button ,"Agree Disclaimer & Show Graph", will be enabled. When
you'd like to clear all checked box at products, click "Clear check" button. In addition, the check boxes grayed out is
disabled to check. You cannot select it.
"Clear check" button
up to 6 prducts
www.rohm.com
© 2016 ROHM Co., Ltd. All rights reserved.
5/10
2016.02 - Rev.001
Design Support Document
ROHM LDO Finder User’s Guide
STEP 3
3.2.4
Click "Agree Disclaimer & Show Graph" button (after reading Disclaimer carefully)
You can click "Agree Disclaimer & Show Graph" button after selecting products' check box.
After clicking "Agree Disclaimer & Show Graph" button, ROHM LDO Finder shows OCP & Vdrop graph at required
onditions. You can compare to those graph you selected before.
Caution : Read disclaimer carefully before clicking the "Agree Disclaimer & Show Graph" button.
3.2.5
Reset setting conditions
When you'd like to reset all conditions (parameters, checked box, shown graphs), please click the "Reset" button.
www.rohm.com
© 2016 ROHM Co., Ltd. All rights reserved.
6/10
2016.02 - Rev.001
Design Support Document
ROHM LDO Finder User’s Guide
STEP 4
3.3
Check the results
Here, it is described that how to use some functions and buttons.
You can check the following results using buttons.
- IOUT vs. VOUT characteristics (OCP)
- Minimum dropout voltage (Vdrop)
- Junction temperature and maximum power dissipation (based on θja)
3.3.1
Radio button in "Graph"
After clicking the "Agree Disclaimer and Show Graph", ROHM LDO Finder displays OCP graph at first. When you'd like
to check the minimum dropout voltage, you can switch displayed graph to "minimum Vdrop" by clicking radio button in
"Graph".
www.rohm.com
© 2016 ROHM Co., Ltd. All rights reserved.
7/10
2016.02 - Rev.001
Design Support Document
ROHM LDO Finder User’s Guide
3.3.2
Radio button in "Display"
After clicking button of the "Agree Disclaimer and Show Graph", you can switch 2 ways for checking graph.
1) Separated
This shows 4 graph lines in each graph block. It differs temperature at each lines and has 4 type as follow.
pink
- at user input temperature
light red
- at recommended highest operating temperature range
light green - at typical temperature (25°C mainly)
light blue
- at recommended lowest operating temperature range
2) Merged
This shows only user input temperature. And if you selected at least 2 products, it will be shown merged graph on the
same graph area.
www.rohm.com
© 2016 ROHM Co., Ltd. All rights reserved.
8/10
2016.02 - Rev.001
Design Support Document
ROHM LDO Finder User’s Guide
3.3.3
Input box in "Axis"
This input box can change axis for all graphs. Here, the "H" changes horizontal axis maximum range, and the "V"
changes vertical axis maximum range.
www.rohm.com
© 2016 ROHM Co., Ltd. All rights reserved.
9/10
2016.02 - Rev.001
Design Support Document
ROHM LDO Finder User’s Guide
3.3.4
Calculation of junction temperature (Tj) and maximum power dissipation (Pd(max))
(based on θja)
After clicking button of the "Agree Disclaimer and Show Graph", column of Tj [°C] and Pd(max)[W], that is in the
parametric search area, is calculated based on θja.
Here shows a result about data in case of existing θja on the parametric search.
These results are calculated by following expression.
Tj = Ta + θja * P
( P = (VIN - VOUT) * IOUT + (VIN * IIN) )
( Ta > 25°C )
Pd(max) = Pd(max)@25°C - (Ta - 25) / θja
If the column ΨJT has a value, you can calculate nearer actual junction temperature.
Please refer to following URL:
http://rohmfs.rohm.com/en/products/databook/applinote/ic/power/switching_regulator/thermal_resistance_appli-e.pdf
Caution: In ROHM LDO Finder, a shown θja is using one of value in the datasheet. In case you need other θja, please
refer datasheet of respective products.
3.3.5
Download PDF (screenshot)
After optimizing the graph setting (refer to 3.3.1 - 3.3.3), you can download 4 graphs' (Graph 2 patterns x Display 2
patterns) screenshot by clicking the button "Download".
www.rohm.com
© 2016 ROHM Co., Ltd. All rights reserved.
10/10
2016.02 - Rev.001
Disclaimer
1.
ROHM’s site terms and conditions of use on our website shall apply to you and your utilization of this technical
information.
2.
This technical information attempt to support users who develop products and/or components incorporating
ROHM’s products, but any information contained in technical information, including, but not limited to, reference
circuit, simulation result and bill of materials is solely for the purpose of reference, not for the purpose of
exemplification or recommendation.
ROHM does not warrant that any Information will meet your input-output specifications, will be suitable for your
application, or will operate as shown in the simulation in a real equipment used for particular purposes.
ROHM ASSUMES NO LIABILITY FOR ANY DAMAGES WHATSOEVER ARISING OUT OF THE INFORMATION
CONTAINED IN THIS DOCUMENT.
You are solely responsible for all respects of design, development and production for your own products, including
but not limited to: designing a final products or components; verifying and testing such final products or
components under actual operating conditions and applicable circumstances; determining the appropriateness of
the use of Information in such final products or components; evaluating and determining the applicability of any
Information.
3.
This technical Information is provided for use AS-IS basis.
ROHM SHALL NOT, EXPRESSLY OR IMPLIEDLY, MAKE ANY WARANNTY OF ANY KIND INCLUDING BUT
NOT LIMITED TO WARRANTIES OF AVAILABILITY, FUNCTIONALITY, CORRECTNESS, MERCHANTABILITY,
FITNESS FOR PARTICULAR PURPOSE.
4.
This technical information is made using public information and specifications, the Information may not be current
at the time of downloading.
ROHM does not warrant the nowness, accuracy and completeness of the Information.
5.
All Information is for reference only. ROHM does not warrant that the Information will not infringe any intellectual
property rights or any other rights of any third party.
ROHM SHALL NOT BE IN ANY WAY RESPONSIBLE OR LIABLE FOR INFRINGEMENT OF ANT
INTELLECTUAL PROPERTY RIGHTS OR OTHER DAMAGES ARISING FROM USE OF SUCH INFORMATION.
No license, expressly or implied, is granted hereby under any intellectual property rights or other rights of ROHM
or any third parties with respect to the Information.
6.
Except for specific applications as expressly stated in ROHM’s data sheet, ROHM’s products described in this
technical information is designed and manufactured for application in ordinary electronic equipment (such as AV
equipment, OA equipment, telecommunication equipment, home electronic appliances, amusement equipment,
etc.).
If you intend to use ROHM’s products in devices requiring extremely high reliability (such as medical
(Note 1)
equipment
, transport equipment, traffic equipment, aircraft/spacecraft, nuclear power controllers, fuel
controllers, car equipment including car accessories, safety devices, etc.) and whose malfunction or failure may
cause loss of human life, bodily injury or serious damage to property (“Specific Applications”), please consult with
ROHM sales representative in advance.
UNLESS OTHERWISE AGREED IN WRITING BY ROHM IN ADVANCE, ROHM SHALL NOT BE IN ANY WAY
RESPONSIBLE OR LIABLE FOR ANY DAMAGES， EXPENSES OR LOSSES INCURRED BY YOU OR THIRD
PARTIES ARISING FROM THE USE OF ANY ROHM’S PRODUCTS OR INFORMATION FOR SPECIFIC
APPLICATIONS.
(Note1) Medical Equipment Classification of the Specific Applications
JAPAN
USA
EU
CHINA
CLASSⅢ
CLASSⅡb
CLASSⅢ
CLASSⅢ
CLASSⅣ
CLASSⅢ
7.
Any system embedding electronic devices can fail or malfunction at a certain rate.
Please be sure to implement, at your own responsibilities, adequate safety measures including but not limited to
fail-safe design against the physical injury, damage to any property, to or for your products, components and
applications.
8.
In no event shall you use in any way whatsoever the products described in this technical information and the
information for any military purposes, including but not limited to, the development of mass-destruction weapons.
9.
ROHM reserves the right to modify, improve or otherwise change its products and/or Information in this technical
information, or to cease or terminate this web simulation services without prior written notice.
Before purchasing or using ROHM’s products, you must refer to and comply with the latest version of all related
technical information for products.
www.rohm.com
© 2016 ROHM Co., Ltd. All rights reserved.
2016.01.12 - Rev.001