tle4998 Infineon Technologies Corporation, tle4998 Datasheet - Page 5

• Manufacturer Part Number: tle4998
• Description: Programmable Linear Hall Sensor
• Manufacturer: Infineon Technologies Corporation

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This document is a supplement to the TLE4998 datasheet.
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1.1
The concept is based on shifting as much of the on-chip sensor processing as possible to the digital domain. This
can be achieved by directly converting the output of the Hall probe into a digital value, without additional, purely
analog pre-processing. The magnetic range setup is also done directly in the first stage of the sigma-delta analog-
to-digital converter (Hall ADC) used in the TLE4998. We call this principle magnetic-to-digital conversion (MDC).
By doing that, and of course by using a Hall ADC with outstanding performance, the compensation requirements
are mainly reduced to the magnetic circuit of the application and the Hall probe itself. All other parts do no longer
have any significant temperature depedency. This principle requires an accurate junction temperature value in
digital form for calculation of compensation polynomials. Accordingly, an accurate temperature ADC is included in
the sensor as well.
compensation concept.
Figure 1
1.2
Figure 2
be programmed in EEPROM. A detailed description on how to access and write those values is given in the
TLE4998 user programming guide.
As illustrated, the processing of the Hall-ADC update occurs with typically 16k SPS (samples per second). The
DSP data processing has to be performed according to the selected Interface mode. For SENT, the processing of
a new output value takes place during the synchronisation frame, for PWM the processing is done before the next
following frame.
User’s Manual
Temperature Coefficient Setup Guide
It is valid for all TLE4998 products and derivatives
It is intended as add-on to the currently available TLE4998 target and/or data sheets
It is recommended to read the programming description of this device before
It gives an overview and detailed description of the temperature compensation concept of the TLE4998
shows the signal flow diagram including important internal data values. The values in green boxes can
Introduction
Concept of the TLE4998 Temperature Compensation
Simplified Block Diagram of the TLE4998
Signal Processing
MAGNETIC
CIRCUIT
(B-Field)
Figure 1
shows a simplified block diagram of the TLE4998 to demonstrate its temperature
Hall probe
fixed biasing
Figure 3
shows the main data processing steps of the TLE4998 digital part.
A
range
setup
D
T
j
5
EEPROM
A
DSP
D
Temperature Coefficient Setup Guide
Generation
Protocol
Digital
OUT Value
Rev 1.1, 2008-10-30
Introduction
TLE4998