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Data Sheet Supplement
Differential Two-Wire Hall Effect Sensor IC
TLE4941-2 TLE4941-2C
For all parameters not specified in this document the TLE4941 data sheet is valid.
PSSO2-1
Type TLE4941-2 TLE4941-2C
Marking 4102E 41C2E
Ordering Code Q62705-K629 Q62705-K631
Package PSSO2-1 PSSO2-2
TLE4941-2, TLE4941-2C Supplement
1 Functional description
= peak detection offset= (max + min) / 2
d1
d1
d2 offset correction
initial settling time
d2
d2
1
2
3
4
5
6
7
PGA switching
phase shift change
uncalibrated mode
calibrated mode
Fig. 1: example for startup behaviour
Uncalibrated mode: Occasionally a short initial offset settling time td,input might delay the detection of the input signal. (The sensor is "blind"). The magnetic input signal is tracked by the speed ADC and monitored within the digital circuit. For detection the signal transient needs to exceed a threshold (digital noise constant d1). When the signal slope is identified as a rising edge (or falling edge), a trigger pulse is issued to a comparator. A second trigger pulse is issued as soon as a falling edge (or rising edge respectively) is detected (and vice versa). Depending on the initial state of the comparator the IC output is first triggerd on the first or second detected edge. Between the start-up of the magnetic input signal and the time when its second extreme is reached, the PGA (programmable gain amplifier) will switch to its appropriate position. This value is determined by the signal amplitude and initial offset value. The digital noise constant value is changing accordingly (d1 d2, related to the corresponding PGA states), leading to a change in phase shift between magnetic input signal and output signal. After that consecutive output edges should have a nominal delay of about 180. In rare cases one further switching of PGA can occur (see appendix B). During the uncalibrated mode the offset value is calculated by the peak detection algorithm as described in the TLE 4941 data sheet.
TLE4941-2 - TLE4941-2C Datasheet supplement
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February 2002
TLE4941-2, TLE4941-2C Supplement
Transition to calibrated mode: In the calibrated mode the output will switch at zero-crossing of the input signal. The phase shift between input and output signal is no longer determined by the ratio between digital noise constant and signal amplitude. Therefore a sudden change in the phase shift may occur during the transition from uncalibrated to calibrated mode.
Calibrated mode: See TLE4941 data sheet.
Additional notes: Unlike the TLE 4941 the first output edge might occur before the first zero-crossing of the magnetic input signal. Therefore the maximum number of edges until the calibrated mode is active is increased by one for TLE4941-2. However, referring to the input signal the delay between star-up of the signal and first calibrated output signal is identical with TLE4941. Typically the phase error due to PGA-transition (row 7 to 15) reduces the error caused by switching the mode from uncalibrated to calibrated. The summed up change in phase error from the first output edge issued to the output edges in calibrated mode will not exceed +/- 90.
TLE4941-2 - TLE4941-2C Datasheet supplement
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February 2002
TLE4941-2, TLE4941-2C Supplement
1 2 3
1
180 (uncal) 38s ...180 (uncal) 38s ...180 (uncal) 38s ...180 (uncal) 38s ...180 (uncal) 135..300 (PGA, uncal) 135..300 (PGA, uncal) 135..300 (PGA, uncal) 135..300 (PGA, uncal) 135..300 (PGA, uncal) 38s ...180 (uncal) 38s ...180 (uncal) 38s ...180 (uncal) 38s ...180 (uncal)
2
90...270 180 (uncal) 180 (uncal) 180 (uncal) 180 (uncal) 180...220
3
4
5
6
7
8
180 (cal) 180 (cal)
9
10
150..200 150..200 150..200 180 (cal) 180 (cal) (cal/uncal) (cal/uncal) (cal/uncal) 90...270 150..200 150..200 150..200 180 (cal) (cal/uncal) (cal/uncal) (cal/uncal) 180 (uncal) 180 (uncal) 180 (uncal) 180 (uncal) 180...220 90...270
180 (cal) 180 (cal)
4
150..200 150..200 150..200 180 (cal) (cal/uncal) (cal/uncal) (cal/uncal) 90...270
180 (cal)
5
180 (uncal) 180 (uncal) 180 (uncal)
150..200 150..200 150..200 180 (cal) (cal/uncal) (cal/uncal) (cal/uncal) 90...270 150..200 150..200 180 (cal) (cal/uncal) (cal/uncal) 180 (cal) 180 (cal)
6
180 (uncal)
7
150..200 150..200 180 (cal) (cal/uncal) (cal/uncal)
8
180 (uncal) 180 (uncal) 180 (uncal) 180 (uncal) 180...260 (PGA, uncal) 180...260 (PGA, uncal) 180...260 (PGA, uncal) 180...260 (PGA, uncal)
150..200 150..200 150..200 150..200 180 (cal) (cal/uncal) (cal/uncal) (cal/uncal) (cal/uncal) 90...270
180 (cal)
9
180 (uncal) 180 (uncal) 180 (uncal) 180...220
150..200 150..200 150..200 150..200 180 (cal) (cal/uncal) (cal/uncal) (cal/uncal) (cal/uncal) 90...270 150..200 150..200 150..200 180 (cal) (cal/uncal) (cal/uncal) (cal/uncal) 90...270 150..200 150..200 180 (cal) (cal/uncal) (cal/uncal) 180 (cal) 180 (cal)
10
180 (uncal) 180 (uncal) 180 (uncal) 180...220
11
180 (uncal)
12
150..200 150..200 180 (cal) (cal/uncal) (cal/uncal)
13
180 (uncal) 180 (uncal) 180 (uncal)
150..200 150..200 150..200 180 (cal) (cal/uncal) (cal/uncal) (cal/uncal) 90...270
180 (cal)
14
180 (uncal) 180 (uncal)
150..200 150..200 150..200 180 (cal) (cal/uncal) (cal/uncal) (cal/uncal) 90...270 150..200 150..200 180 (cal) (cal/uncal) (cal/uncal)
15
180 (uncal)
Table1: overview of the start-up behaviour. In the first row the edge number is given. The following rows show different possibilities for the nominal delays between the edges. Numbers are calculated for sinusoidal input signals. Additionally the specified tolerances have to be taken into account (e.g. Jitter) Rows 2..6: behaviour at small input amplitudes (B< approx. 3.5mT) Rows 7..11: behaviour at initial phases of -90 .. 0 Rows 12..15: behaviour at initial phases of 0.. 90 Remark: the additional PGA switching can only occur once per row. Therefore also the additional phase shift marked "150..200 (cal/uncal)" will only occur once per row. (see example)
TLE4941-2 - TLE4941-2C Datasheet supplement
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February 2002
TLE4941-2, TLE4941-2C Supplement
Example: B = 10mT sin (t + ). = 30
Typical startup-behaviour at a sinusoidal input signal of 10mT amplitude, initial phase= 30.
1 2 3 333,2 4 513,2 5 693,2 6 900
180 (cal)
7 1080
180 (cal)
8 1260
180 (cal)
9 1440
10 ...
180 (cal)
43,6 133,9
90,3 (PGA, uncal)
199,3 (PGA, uncal)
180 (uncal)
180 (uncal)
206,8 (Offsetcorrection)
This corresponds to row 14 in the table, behaviour similar to Fig. 1
As a special (and rare) case instead of an offset correction after edge number 5, a further (extra) PGA switching could occur before edge number 5. PGA switching inhibits an immediate offset update. It can happen if one of the signal peaks is exactly at a PGA switching threshold (speed-ADC overflow). In this case the offset update (switching from uncalibrated mode to calibrated mode) would be delayed by two to three further edges. The referring phase shifts of the example would then be as follows:
1 2 3 333,2 4 513,2 5 727,5 6 907,5 7 1087,5 8 1260
180 (cal)
9 1440
10 ...
180 (cal)
43,6 133,9
90,3 (PGA, uncal)
199,3 (PGA, uncal)
180 (uncal)
214,3 (extra PGA)
180 (uncal)
180 (uncal)
172,5 (Offsetcorrection)
This corresponds to row 13 of the table.
Circuit Description See TLE4941 data sheet
TLE4941-2 - TLE4941-2C Datasheet supplement
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February 2002
TLE4941-2, TLE4941-2C Supplement
2 Additions/Changes for TLE4941-2 versus TLE 4941
(All values are valid for constant amplitude and offset of input signal, f<2500Hz) Parameter Signal behaviour after undervoltage or standstill>tStop Symbol min. typ. max. Unit Conditions Magnetic edge amplitude according to B
Limit, early startup
nDZ-Start
Edges that occur before nDZ-Start can be suppressed 2 3 edges edges 1Hz f 2000Hz f > 2000Hz td,input has to be taken into account Shortest time delay between input signal edge 1 and 2 td,input has to be taken into account Systematical phase error of "uncal" edge; nth vs. n+1th edge (does not include random phase error) nd after the 2 edge
Systematic phase error of output edges during startup and uncalibrated mode
38
s
-88
+88
Phase shift change during PGA switching Phase shift change during transition switch from uncalibrated to calibrated mode Number of edges in uncalibrated nDZ-Startup mode in rare cases (see appendix B) nDZ-Startup
0
80
-90
+90
6
edges
8
edges
TLE4941-2 - TLE4941-2C Datasheet supplement
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February 2002
TLE4941-2, TLE4941-2C Supplement
Parameter Jitter during uncalibrated mode
Symbol SJitClose (1-value) SJitFar (1-value) SJitAC (1-value)
min.
typ.
max. 3 4 5 7 3
Unit % % % % %
Conditions -40C Tamb 150C 150C Tamb 170C -40C Tamb 150C 150CTamb 170C see TLE 4941 data sheet These magnetic field changes are necessary for startup with the second edge
Magnetic field amplitude change necessary for early startup of the -2 Versions B
Limit, early startup
> 2 * ? B Limit + X% (X=10)
Permitted time for edges to
BLimit,
early startup
0.7
1.6 3.0 +10% +10% 1.76 3.3
mT
0.7
mT necessary for startup with the second edge f < 1s
exceed BLimit,
early startup
t Limit, slow
early startup
590
ms
Behaviour at magnetic input signals slower than Tstop (self-calibration time period):
Unlike the TLE4941 magnetic changes exceeding BLimit, early startup can cause output switching
of the TLE4941-2, even at f significantly lower than 1Hz. Depending on their amplitude edges slower than t Limit, slow early startup might be detected. If the digital noise constant ( BLimit,early startup ) is not exceeded before a new initial self-calibration is started, the output of the corresponding edge will be inhibited. This depends on signal amplitude and initial phase.
3
Additional remarks
All additional parameters for TLE4941-2 are guaranteed by design, based on lab characterizations. For series production additional to the parameters of TLE4941 (standard type) only nDZ-start is tested.
TLE4941-2 - TLE4941-2C Datasheet supplement
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February 2002
TLE4941-2, TLE4941-2C Supplement
Appendix B Release 1.0 1. Occurrence of initial calibration delay time td,input Identical to TLE4941, TLE4941C appendix B.
2. Magnetic input signal extremely close to a PGA switching threshold during signal start-up: After signal start-up normally all PGA switching into the appropriate gain state happens within less than one signal period. This is included in the calculation for nDZ-Startup. For the very rare case that the signal amplitude is extremely close to a switching threshold of the PGA and the full range of the following speed ADC respectively, a slight change of the signal amplitude can cause one further PGA switching. It can be caused by non-perfect magnetic signal (amplitude modulation due to tolerances of polewheel, tooth wheel or air gap variation). This additional PGA switching can result in a further delay of the output signal (nDZStartup)
up to three magnetic edges leading to a worst case of nDZ-Start=9 and nDR-Startup=11.
However, the speed signal start-up, comprised of nDR-Startup and td,input is not affected by this behaviour for TLE4941-2.
TLE4941-2 - TLE4941-2C Datasheet supplement
8
February 2002

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