TLE4998C8(D)

SPC Output

Data Sheet

16

Revision 1.1, 2017-01

The status nibble allows to check internal states and conditions of the sensor.

•

Depending on the selected SPC mode, the first two bits of the status nibble contain either the selected

magnetic range or the ID of the sensor and allow therefore an easy interpretation of the received data.

•

The third bit is set to 1 for the first transmission after the sensor returns from an overvoltage operation with

disabled open drain stage to regular operation (see Chapter 9).

•

The fourth bit is switched to 1 for the first data package transferred after a reset.

7.2

Unit Time Setup

The basic SPC protocol unit time granularity is defined as 3 μs. Every timing is a multiple of this basic time unit.

To achieve more flexibility, trimming of the unit time can be used to:

•

Allow a calibration trim within a timing error of less than 20% clock error (as given in SAE standard)

•

Allow a modification of the unit time for small speed adjustments

This enables a setup of different unit times. The output characteristic depends on the external load, the wiring, as

well on the pull-up resistor and the temperature. Furthermore, sufficient driving capability of the reciever is

required, in order to fulfill the master pulse requirements.

The nominal unit time is calculated by:

(7.1)

7.3

Master Pulse

An SPC transmission is initiated by a Master pulse from the ECU on the OUT pin. To detect a low-level on the

OUT pin, the voltage has to be below a threshold

V

soon as

V

well as the total trigger time

t

sections.

It is recommended to choose the typical master low time exactly between the minimum and the maximum possible

time:

t

low time exceeds the maximum low time, the sensor does not respond and is available for a next triggering 30μs

Table 7-2

Mapping of Temperature Value

Junction Temperature

Typ. Decimal Value from Sensor

Note

- 55 °C

0

1) Theoretical range of temperature values, not operating temperature range.

0°C

55

–

25 °C

80

–

200 °C

255

Theoretical upper limit1)

Table 7-3

Pre-divider Setting

Parameter

Symbol

Values

Unit

Note / Test Condition

Min.

Typ.

Max.

Unit time

t

UNIT

2.0

–

3.88

μs

Clk

1)2)

1) Default setting is 3 μs nominal SPC unit time.

2) Subject to RC oscillator frequency variation ± 20%.