ROHM REFLED004-EVK-001 Backlight LED Driver User Guide

ROHM REFLED004-EVK-001 Backlight LED Driver

Product Information

The BD83A14EFV-M Evaluation Board (REFLED004-EVK-001) is a high voltage LED driver designed for automotive backlight applications such as CID, cluster panel, car navigation, HUD, or car audio system. It features a built-in current driver boost DC/DC converter and supports up to 4 channels of white LEDs. The evaluation board comes with default operating conditions for power supply voltage, LED configuration, output voltage, output current, DC/DC oscillation frequency, over voltage limit, and over current limit.

Default Operating Conditions

＜High Voltage Safety Precautions＞

• Read all safety precautions before use

Please note that this document covers only the BD83A14EFV-M evaluation board (REFLED004-EVK-001) and its functions. For additional information, please refer to the datasheet.  To ensure safe operation, please carefully read all precautions before handling the evaluation board  Depending on the configuration of the board and voltages used, Potentially lethal voltages may be generated. Therefore, please make sure to read and observe all safety precautions described in the red box below.

Product Usage Instructions

Before Use

1. Verify that the parts/components are not damaged or missing (i.e. due to drops).
2. Check that there are no conductive foreign objects on the board.
3. Be careful when performing soldering on the module and/or evaluation board to ensure that solder splash does not occur.
4. Check that there is no condensation or water droplets on the circuit board.

During Use

5. Be careful to not allow conductive objects to come into contact with the board.
6. Brief accidental contact or even bringing your hand close to the board may result in discharge and lead to severe injury or death. Therefore, DO NOT touch the board with your bare hands or bring them too close to the board. In addition, exercise extreme caution when using conductive tools such as tweezers and screwdrivers.
7. If used under conditions beyond its rated voltage, it may cause defects such as short-circuit or, depending on the circumstances, explosion or other permanent damages.
8. Be sure to wear insulated gloves when handling is required during operation.

After Use

9. The ROHM Evaluation Board contains circuits that store high voltage charges even after the connected power circuits are cut. Please discharge the electricity after using it and deal with it after confirming such electric discharge.
10. Protect against electric shocks by wearing insulated gloves when handling.

Note: This evaluation board is intended for use only in research and development facilities and should be handled only by qualified personnel familiar with all safety and operating procedures. We recommend carrying out operation in a safe environment that includes the use of high voltage signage at all entrances, safety interlocks, and protective glasses.

Introduction

This user’s guide will provide the necessary steps to operate the Evaluation Board of ROHM’s BD83A14EFV-M LED Driver. This document includes the external parts, operating procedures and application data.

Description

This Evaluation Board was developed for ROHM’s LED Driver BD83A14EFV-M. BD83A14EFV-M is a white LED driver for LCD backlight. It has 4ch Current Driver for LED Drive, and it is suitable for high illumination LED drive. It is suitable for middle size LCD panel drive because LED pin maximum voltage is 50 V.
The dimming is controlled by the PWM signal and can be set up to 20,000: 1@100 Hz.
It also supports analog dimming and can accommodate even higher brightness ranges by combining with PWM dimming. DC/DC converters can be controlled for boost applications, and the input operating voltage range is 4.5 V to 48V.

Application

Automotive backlight application for CID, cluster panel, car navigation, HUD, or car audio system.

Evaluation board operating condition (default setting)

1. This indicates the voltage near the VCC pin. Be careful of voltage drop by the impedance of power line.
2. Output voltage is determined by the Vf value of the connected LED and the numbers of series. Since this evaluation board has a boost-configuration, output voltage should be higher than input voltage. Also, output voltage should be lower than OVP voltage. *3 The default frequency is set to 400kHz so that it is higher than the EMC standard (LW: 150kHz to 300kHz) even if variations and SSCG functions are considered.

Evaluation board

Evaluation board setup

Operating procedure

1. Connect panel or LEDs to evaluation board. (Anode to VOUT-pin. Cathode to LEDx-pin.)
2. Connect power supply to +B-pin and –B-pin of the evaluation board.
3. Connect power supply to EN-pin. It must be less than 7V.
4. Connect pulse generator to PWM-pin. It should be 100Hz to 25kHz and the minimum pulse width must be longer than 0.5μs.
5. Turn on the power supply for +B-pin.
6. Turn on the power supply for EN-pin.
7. Turn on the pulse generator for PWM-pin.

Operation mode settings

The table below describes the settings for SYNC terminals.

For unused channels, pull down the LED pin to GND with 10kΩ.

The ISET terminal voltage can be adjusted according to the voltage input to the ADIM_P terminal. The LED current can be calculated from the following equation.

1LED is the output current per 1ch (LED current)
(Recommended operating condition:20 mA to 120 mA) ????? is the LED current setting resistor
(Recommended operating condition:8.8kΩ to 53kΩ) ????? is the ADIM_P pin input OnDuty
(Recommended operating condition:18% to 100%)

Pin configuration

Evaluation board schematic

Parts list

Board layout

Evaluation board PCB information

The layout of BD83A14EFV-M is shown below.

Reference application data

(Ta=25°C, Output voltage=34V, Iout=120mA x 4ch)

Revision history

Notes

1. The information contained herein is subject to change without notice.
2. Before you use our Products, please contact our sales representative and verify the latest specifica-tions :
3. Although ROHM is continuously working to improve product reliability and quality, semicon-ductors can break down and malfunction due to various factors.
4. Therefore, in order to prevent personal injury or fire arising from failure, please take safety measures such as complying with the derating characteristics, implementing redundant and fire prevention designs, and utilizing backups and fail-safe procedures. ROHM shall have no responsibility for any damages arising out of the use of our Poducts beyond the rating specified by ROHM.
5. Examples of application circuits, circuit constants and any other information contained herein are provided only to illustrate the standard usage and operations of the Products. The peripheral conditions must be taken into account when designing circuits for mass production.
6. The technical information specified herein is intended only to show the typical functions of and examples of application circuits for the Products. ROHM does not grant you, explicitly or implicitly, any license to use or exercise intellectual property or other rights held by ROHM or any other parties. ROHM shall have no responsibility whatsoever for any dispute arising out of the use of such technical information.
7. The Products specified in this document are not designed to be radiation tolerant.
8. For use of our Products in applications requiring a high degree of reliability (as exemplified below), please contact and consult with a ROHM representative : transportation equipment (i.e. cars, ships, trains), primary communication equipment, traffic lights, fire/crime prevention, safety equipment, medical systems, servers, solar cells, and power transmission systems.
9. Do not use our Products in applications requiring extremely high reliability, such as aerospace equipment, nuclear power control systems, and submarine repeaters.
10. ROHM shall have no responsibility for any damages or injury arising from non-compliance with the recommended usage conditions and specifications contained herein.
11. ROHM has used reasonable care to ensure the accuracy of the information contained in this document. However, ROHM does not warrants that such information is error-free, and ROHM shall have no responsibility for any damages arising from any inaccuracy or misprint of such information.
12. Please use the Products in accordance with any applicable environmental laws and regulations, such as the RoHS Directive. For more details, including RoHS compatibility, please contact a ROHM sales office. ROHM shall have no responsibility for any damages or losses resulting non- compliance with any applicable laws or regulations.
13. When providing our Products and technologies contained in this document to other countries, you must abide by the procedures and provisions stipulated in all applicable export laws and regulations, including without limitation the US Export Administration Regulations and the Foreign
14. Exchange and Foreign Trade Act.
15. This document, in part or in whole, may not be reprinted or reproduced without prior consent of ROHM.

Thank you for your accessing to ROHM product informations. More detail product informations and catalogs are available, please contact us.

ROHM Customer Support System

http://www.rohm.com/contact/

www.rohm.com
© 2016 ROHM Co., Ltd. All rights reserved.

References

• ROHM Semiconductor - ROHM Co., Ltd.
• contactus

Read User Manual Online (PDF format)

Read User Manual Online (PDF format)  >>

Download This Manual (PDF format)

Download this manual  >>