TLE4998S8D Datasheet, PDF (19/23 Pages) Infineon Technologies AG – High Performance Programmable Dual Linear Hall Sensor

TLE4998S8D Grade1
SENT Output Definition (SAE J2716)
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SENT Output Definition (SAE J2716)
The sensor supports a basic version of the Single Edge Nibble Transmission (SENT) protocol defined by SAE.
The main difference between the standard version and its implementation in the TLE4998 is the usage of an open
drain instead of a push-pull output.
9.1
Basic SENT Protocol Definition
• The single edge is defined by a 9-μs low pulse on the output, followed by the high time defined in the protocol
(nominal values, may vary by tolerance of internal RC oscillator and the programming, see Chapter 9.2). All
values are multiples of a 3-μs unit time frame concept. A transfer consists of the following parts:A
synchronization period of 168 μs (in parallel, a new sample is calculated)
• A synchronization period of 56 UT (in parallel, a new sample is calculated)
• A status nibble of 38-81 μs
• Three data nibbles of 36-81 μs (data packet 1 with a length of 103-243 μs)
• Three data nibbles of 36-81 μs (data packet 2 with a length of 103-243 μs)
• A CRC nibble of 38-81 μs
Sensor processing
sensor
idle
compensate the
sample
check
lowtime,
process
transfer compensated sample
sensor
idle
Output pin (physical)
falling edge/ low time of
master requires sensor
response
Transferred data (logical)
sync. period
Status
nibble
Data
nibble 1
high
Data
nibble 2
low
CRC zero
nibble nibble
Figure 9-1 SENT Frame
The CRC checksum calculation includes the status nibble and the data nibbles. This leads to a minimum transfer
time of 456 μs, and a maximum transfer time of 816 μs per sample.
It is important to know that the sampling time (when values are taken for temperature compensation) here is
always defined as the beginning of the synchronization period; during this period, the resulting data is always
calculated from scratch.
As only one Hall value needs to be transferred within one sequence, the second data package is divided into two
parts (see Figure 9-2).
• First, the remaining 4 LSBs of the Hall signals are transferred in the first data nibble. This means the receiver
may use the whole 16-bit data available in the sensor when reading and using all 4 nibbles transferred.
• Second, the temperature is transferred as an 8-bit value. The value is transferred in unsigned integer format
and corresponds to -55°C to 200°C. For example, transferring the value 55 corresponds to 0°C. The
temperature is additional information and although it is not calibrated, may be used for a plausibility check, for
example.
Technical Product Description
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Revision 1.0, 2013-02-22