Data Sheet Supplement
Differential Two-Wire Hall Effect Sensor IC TLE 4941-2
TLE 4941-2 C
For all parameters not specified in this document the TLE 4941 data sheet is valid.
P-SSO-2-1
Type Marking Ordering Code Package
TLE 4941-2 4102E Q62705-K0629 P-SSO-2-1
TLE 4941-2C 41C2E Q62705-K0631 P-SSO-2-2
TLE 4941-2 - TLE 4941-2C Supplement
TLE 4941-2 TLE 4941-2C April 2001
Data Sheet 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 4 5 6 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 triggered on the
first or second detected edge.
Between the startup 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.
TLE 4941-2 - TLE 4941-2C Supplement
TLE 4941-2 TLE 4941-2C April 2001
Data Sheet 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 TLE 4941 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 TLE 4941-2. However, referring to
the input signal the delay between startup of the signal and first calibrated output
signal is identical with TLE 4941.
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°.
TLE 4941-2 - TLE 4941-2C Supplement
TLE 4941-2 TLE 4941-2C April 2001
Data Sheet Supplement
4
11 2 3 4 5 6 7 8 9 10
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 startup-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)
TLE 4941-2 - TLE 4941-2C Supplement
TLE 4941-2 TLE 4941-2C April 2001
Data Sheet 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°
2
133,9°
3
333,2°
4
513,2°
5
693,2°
6
900°
7
1080°
8
1260°
9
1440°
10
...
∆ϕ90,9°
(PGA,
uncal)
133,3°
(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°
2
133,9°
3
333,2°
4
513,2°
5
727,5°
6
907,5°
7
1087,5°
8
1260°
9
1440°
10
...
∆ϕ90,9°
(PGA,
uncal)
133,3°
(PGA,
uncal)
180°
(uncal) 213,8°
(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 TLE 4941 - TLE 4941 C data sheet
TLE 4941-2 - TLE 4941-2C Supplement
TLE 4941-2 TLE 4941-2C April 2001
Data Sheet Supplement
6
2 Additions/Changes for TLE 4941–2 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
startup- 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
TLE 4941-2 - TLE 4941-2C Supplement
TLE 4941-2 TLE 4941-2C April 2001
Data Sheet 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 differential field
amplitude change
necessary for early startup:
startupearly Limit,
B
ˆ
∆startupearly
Limit,
B
ˆ
∆0.7 1.76 3.3 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 < 1 Hz
Behaviour at magnetic input signals slower than Tstop (self-calibration time period):
Unlike the TLE 4941 magnetic changes exceeding startupearly Limit,
B
ˆ
∆ can cause output
switching of the TLE 4941-2, even at f significantly lower than 1Hz. Whether an output
transition is issued or not depends on signal amplitude and signal frequency. In quiescent
condition the internal operation of the IC is divided into time intervals of length Tstop. At each
Tstop a new self-calibration is started if no output transition has occurred. Whenever the
magnetic field change exceeds the digital noise constant before the Tstop interval is finished,
the output is set to the correct state. At the same time a new time interval of length Tstop is
started without doing a new calibration.
3 Additional remarks
All additional parameters for TLE 4941-2 are guaranteed by design, based on lab
characterisations. For series production additional to the parameters of TLE4941
(standard type) only nDZ-start is tested.
TLE 4941-2 - TLE 4941-2C Supplement
TLE 4941-2 TLE 4941-2C April 2001
Data Sheet Supplement
8
Appendix B : TLE 4941-2 - TLE 4941-2C
1. Occurrence of initial calibration delay time td,input
Identical to TLE 4941, TLE 4941 C Appendix B.
2. Magnetic input signal extremely close to a PGA switching threshold during signal
startup:
After signal startup 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 startup, comprised of nDR-Startup and td,input is not affected by this
behaviour for TLE 4941-2.
