Texas Instruments TIDA-00642 User Manual

TIDA-00642 Foot controller Using Analog Hall Sensor

Design Overview

TIDA-00642 uses analog Hall Sensor DRV5053
and OpAmp LMV612 to achieve a foot controller
circuit with approximate linear response and
adjustable quiescent offset and the full scale
output range.

Design Resources

 0 to 5V full scale output ability
 Adjustable quiescent offset voltage at

zero magnet field

 Adjustable wide range system sensitivity
 Low power RRIO amplifier stage
 Cost effective

Featured Applications

TIDA-00642 Design Folder
DRV5053 Product Folder
LMV612 Product Folder
OpAmp Application Guide

Design Features

 Approximate linear response of the

position to output voltage

 Adapt with wide magnet types and range

of flux density

 Foot controller
 Industrial control stick
 Industrial foot pedal
 Key stroke monitor
 General position or angular sensing

1. Introduction

Analog Hall sensor can be used as position or angular sensing with the benefits of no contact and
wearing, high stability and repeat positioning accuracy and wide sensibility range. There are normally
two major methods of the configuration of the magnet and the Hall senor, non-linear and linear way.
This design gives introduction of the two methods and focuses on the linear configuration, and gives
OpAmp circuit design to achieve wide adaption to different applications.

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TIDA-00642 Foot controller Using Analog Hall Sensor

2. Magnet Configuration

The following figures show the two configurations of the magnet and Hall sensor. In non-linear way, the
magnet is approaching the Hall sensor with one of its pole. The output is non-linear to the approaching
distance. In linear configuration, the Hall sensor is placed at the mid position of the magnet as the
quiescent position, no perpendicular flux through the Hall sensor. When the magnet departs from the
quiescent position, the output can change two-way up or down depending on the moving direction.
With the help of OpAmp stage, both the two configurations can output 0 to 5V continual analog signal.
Please refer to Figure 1 and Figure 2 for the two configurations.

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Figure 1. Non-linear magnet configuration

TIDA-00642 Foot controller Using Analog Hall Sensor

Figure 2. Linear magnet configuration

3. OpAmp Circuit

The output of DRV5053 is about 0.2V to 1.8V with the quiescent 1V at zero field or no perpendicular
flux to the sensing surface. In non-linear configuration, the output range is limited either from 0.2V to
1V or from 1V to 1.8V. An OpAmp stage is introduced in this design. It deals with the raw Hall sensor
output signal with adjustable offset and scaling range, shown in Figure 3.

Figure 3. OpAmp stage

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