ROHM BD14210G-LA Current Sense Amplifier User Guide

: June 10, 2024
: ROHM

Table of Contents

BD14210G-LA Current Sense Amplifier
Read User Manual Online (PDF format)
Download This Manual (PDF format)

BD14210G-LA Current Sense Amplifier
User Guide

BD14210G-LA Current Sense Amplifier

Error value when REF terminal voltage is applied by resistor voltage divider
This user’s guide explains the voltage value discrepancy when the voltage applied to the REF pin on the current sense amplifier evaluation board BD14210G-EVK-001 is applied by an external resistor voltage divider.
About BD14210G-EVK-001
BD14210G-EVK-001 is an evaluation board for the current sense amplifier BD14210G-LA. (Figure 1) For details, please refer to the user’s guide at URL below.
https://fscdn.rohm.com/en/products/databook/applinote/ic/sensor/current /bd14210g-evk-001_ug-e.pdf ROHM BD14210G-LA Current Sense
Amplifier Error in REF pin voltage
BD14210G-EVK-001 is designed to apply voltage to the REF pin by resistive voltage divider of R1 and R2 as shown in Figure 2.
When applying voltage to the REF pin by resistive voltage divider, it is necessary to consider the voltage deviation due to the internal resistance of the IC. ROHM BD14210G-LA Current Sense Amplifier - circuit
diagram

The equivalent circuit of the REF pin is shown in Figure 3, and the voltage shift is caused by the 1100kΩ resistance inside the IC. The equations are shown in Equations 1 and 2 below.
Vpullup-R1(I2+I3）＝ R2I2 …1
R2I2 ＝ R3I3+1/3*VDD …2
By calculating I2 from the above equation, it is possible to calculate the REF pin voltage value when applied by resistive voltage divider. ROHM BD14210G-LA
Current Sense Amplifier - circuit diagram 1 Calculation results for varying R1/R2 resistance values under the following conditions are posted below. Please use them as a reference for your design.
VDD=Vpullup=5.0V

R1,R2 (kΩ)	REF Voltage(V)
1000	2.24
500	2.346
100	2.464
10	2.496
1	2.5

The above results are calculated under Typical conditions and do not take into account variations.
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 specifications :
3. Although ROHM is continuously working to improve product reliability and quality, semiconductors can break down and malfunction due to various factors.
  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.
4. 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.
5. 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.
6. The Products specified in this document are not designed to be radiation tolerant.
7. 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.
8. Do not use our Products in applications requiring extremely high reliability, such as aerospace equipment, nuclear power control systems, and submarine repeaters.
9. ROHM shall have no responsibility for any damages or injury arising from non-compliance with the recommended usage conditions and specifications contained herein.
10. 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.
11. 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.
12. 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 Exchange and Foreign Trade Act.
13. This document, in part or in whole, may not be reprinted or reproduced without prior consent of ROHM.