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 Marking Ordering Code Package
TLE4941-2 4102E Q62705-K629 PSSO2-1
TLE4941-2C 41C2E Q62705-K631 PSSO2-2
TLE4941-2, TLE4941-2C Supplement
TLE4941-2 - TLE4941-2C February 2002
Datasheet supplement 2
1 Functional description
offset correction
= peak detection
offset= (max + min) / 2
uncalibrated mode calibrated mode
d1
initial
settling
time
d1 d2
PGA
switching
1 2 3 456 7
d2 d2
phase shift change
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 Supplement
TLE4941-2 - TLE4941-2C February 2002
Datasheet supplement 3
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 Supplement
TLE4941-2 - TLE4941-2C February 2002
Datasheet supplement 4
112345678910
2180°
(uncal) 90...270° 150°..200°
(cal/uncal) 150°..200°
(cal/uncal) 150°..200°
(cal/uncal) 180° (cal) 180° (cal) 180° (cal) 180° (cal)
338µs
...180°
(uncal)
180°
(uncal) 90...270° 150°..200°
(cal/uncal) 150°..200°
(cal/uncal) 150°..200°
(cal/uncal) 180° (cal) 180° (cal) 180° (cal)
438µs
...180°
(uncal)
180°
(uncal) 180°
(uncal) 90...270° 150°..200°
(cal/uncal) 150°..200°
(cal/uncal) 150°..200°
(cal/uncal) 180° (cal) 180° (cal)
538µs
...180°
(uncal)
180°
(uncal) 180°
(uncal) 180°
(uncal) 90...270° 150°..200°
(cal/uncal) 150°..200°
(cal/uncal) 150°..200°
(cal/uncal) 180° (cal)
638µs
...180°
(uncal)
180°
(uncal) 180°
(uncal) 180°
(uncal) 180°
(uncal) 90...270° 150°..200°
(cal/uncal) 150°..200°
(cal/uncal) 180° (cal)
7135°..300°
(PGA,
uncal)
180...220° 180°
(uncal) 180°
(uncal) 150°..200°
(cal/uncal) 150°..200°
(cal/uncal) 180° (cal) 180° (cal) 180° (cal)
8135°..300°
(PGA,
uncal)
180°
(uncal) 180...220° 150°..200°
(cal/uncal) 150°..200°
(cal/uncal) 150°..200°
(cal/uncal) 150°..200°
(cal/uncal) 180° (cal) 180° (cal)
9135°..300°
(PGA,
uncal)
180°
(uncal) 180°
(uncal) 90...270° 150°..200°
(cal/uncal) 150°..200°
(cal/uncal) 150°..200°
(cal/uncal) 150°..200°
(cal/uncal) 180° (cal)
10 135°..300°
(PGA,
uncal)
180°
(uncal) 180°
(uncal) 180°
(uncal) 90...270° 150°..200°
(cal/uncal) 150°..200°
(cal/uncal) 150°..200°
(cal/uncal) 180° (cal)
11 135°..300°
(PGA,
uncal)
180°
(uncal) 180°
(uncal) 180°
(uncal) 180°
(uncal) 90...270° 150°..200°
(cal/uncal) 150°..200°
(cal/uncal) 180° (cal)
12 38µs
...180°
(uncal)
180°...260°
(PGA,
uncal)
180...220° 180°
(uncal) 150°..200°
(cal/uncal) 150°..200°
(cal/uncal) 180° (cal) 180° (cal) 180° (cal)
13 38µs
...180°
(uncal)
180°...260°
(PGA,
uncal)
180°
(uncal) 180...220° 150°..200°
(cal/uncal) 150°..200°
(cal/uncal) 150°..200°
(cal/uncal) 180° (cal) 180° (cal)
14 38µs
...180°
(uncal)
180°...260°
(PGA,
uncal)
180°
(uncal) 180°
(uncal) 90...270° 150°..200°
(cal/uncal) 150°..200°
(cal/uncal) 150°..200°
(cal/uncal) 180° (cal)
15 38µs
...180°
(uncal)
180°...260°
(PGA,
uncal)
180°
(uncal) 180°
(uncal) 180°
(uncal) 90...270° 150°..200°
(cal/uncal) 150°..200°
(cal/uncal) 180° (cal)
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 Supplement
TLE4941-2 - TLE4941-2C February 2002
Datasheet supplement 5
Example: ∆B = 10mT sin (ωt + ϕ). ϕ = 30°
Typical startup-behaviour at a sinusoidal input signal of 10mT amplitude, initial phase= 30°.
ϕ1
43,6°
2
133,9°
3
333,2°
4
513,2°
5
693,2°
6
900°
7
1080°
8
1260°
9
1440°
10
...
∆ϕ90,3°
(PGA,
uncal)
199,3°
(PGA,
uncal)
180°
(uncal) 180°
(uncal) 206,8°
(Offset-
correction)
180°
(cal) 180°
(cal) 180°
(cal) 180°
(cal)
→ 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:
ϕ1
43,6°
2
133,9°
3
333,2°
4
513,2°
5
727,5°
6
907,5°
7
1087,5°
8
1260°
9
1440°
10
...
∆ϕ90,3°
(PGA,
uncal)
199,3°
(PGA,
uncal)
180°
(uncal) 214,3°
(extra PGA) 180°
(uncal) 180°
(uncal) 172,5°
(Offset-
correction)
180°
(cal) 180°
(cal)
→ This corresponds to row 13 of the table.
Circuit Description
See TLE4941 data sheet
TLE4941-2, TLE4941-2C Supplement
TLE4941-2 - TLE4941-2C February 2002
Datasheet supplement 6
2 Additions/Changes for TLE4941–2 versus TLE 4941
(All values are valid for constant amplitude and offset of input signal, f<2500Hz)
Parameter Symbol min. typ. max. Unit Conditions
Signal behaviour
after undervoltage
or standstill>tStop nDZ-Start
2
3
edges
edges
Magnetic edge
amplitude according
to
startupearly Limit,
B
ˆ
∆
Edges that occur
before nDZ-Start
can be suppressed
1Hz ≤ f ≤ 2000Hz
f > 2000Hz
td,input has to be taken
into account
38 µs Shortest time delay
between input signal
edge 1 and 2
td,input has to be taken
into account
Systematic phase
error of output
edges during start-
up and
uncalibrated
mode -88 +88 °Systematical phase
error of “uncal”
edge; nth vs. n+1th
edge (does not
include random
phase error)
Phase shift change
during PGA
switching 0 80 °after the 2nd edge
Phase shift change
during transition
from uncalibrated
to calibrated mode
∆Φswitch -90 +90 °
Number of edges
in uncalibrated
mode nDZ-Startup 6edges
in rare cases (see
appendix B) nDZ-Startup 8edges
TLE4941-2, TLE4941-2C Supplement
TLE4941-2 - TLE4941-2C February 2002
Datasheet supplement 7
Parameter Symbol min. typ. max. Unit Conditions
Jitter during uncalibrated
mode SJitClose
(1σ-value)
± 3
± 4
%
%-40°C ≤Tamb ≤ 150°C
150°C ≤Tamb ≤
170°C
SJitFar
(1σ-value)
± 5
± 7
%
%-40°C ≤Tamb ≤ 150°C
150°C≤Tamb ≤170°C
SJitAC
(1σ-value)
± 3 %see TLE 4941
data sheet
Magnetic field amplitude
change necessary for early
startup of the –2 Versions
startupearly Limit,
B
ˆ
∆
%XB
ˆ
?*2Limit +>
(X=10)
startupearly Limit,
B
ˆ
∆0.7
0.7
1.6
+10%
1.76
3.0
+10%
3.3
mT
mT
These magnetic field
changes are
necessary for startup
with the second
edge
Permitted time for edges to
exceed startupearly Limit,
B
ˆ
∆
startupearly slow Limit,
t
∆
590 ms
necessary for startup
with the second
edge
f < 1s
Behaviour at magnetic input signals slower than Tstop (self-calibration time period):
Unlike the TLE4941 magnetic changes exceeding startupearly Limit,
B
ˆ
∆ can cause output switching
of the TLE4941-2, even at f significantly lower than 1Hz. Depending on their amplitude edges
slower than startupearly slow Limit,
t
∆
might be detected. If the digital noise constant ( startupearly Limit,
B
ˆ
∆)
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 Supplement
TLE4941-2 - TLE4941-2C February 2002
Datasheet supplement 8
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 (nDZ-
Startup) up to three magnetic edges leading to a worst case of n
DZ-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.
