The application circuits in this chapter show the various connection possibilities of the TLE5501. It can be used
in a single ended mode (only one sine and one cosine signal, Figure 1 and Figure 3) and in a differential mode
with a total of four output signals (Figure 2 and Figure 4).
To fully implement the safety concept of the TLE5001 E0002 version and achieve highest diagnostic coverage,
the four output signals have to be sampled singled ended. This is necessary, as the proposed external safety
mechanisms in the Safety Manual act on the single ended signals. Nevertheless, to reach highest angle
accuracy, the differential calculated angle shall be used for the application. The single ended signals are for
diagnostic only.
Figure 1 Application circuit for TLE5501 E0001 single ended signal used
Figure 2 Application circuit for TLE5501 E0001 differential signal used
User’s Manual3Rev. 1.0
2019-04-29
TLE5501
SIN_P
VDD_P
COS_P
GND_P
COS_N
SIN_N
GND_N
TLE5501
VDD_N
C
b
C
b
10 0n
SIN_P
VDD_P
COS_P
GND_P
SIN_P
VDD_P
COS_P
GND_P
COS_N
SIN_N
GND_N
TLE5501
VDD_N
C
b
C
b
10 0n10 0n
C
b
C
b
GND_N
SIN_N
VDD_N
COS_N
SIN_P
VDD_P
COS_P
GND_P
TMR-Based Angle Sensor
Application Circuits
Figure 3 Application circuit for TLE5501 E0002 single ended signal used
Figure 4 Application circuit for TLE5501 E0002 differential signal used
It is recommended to use a 100nF capacitor on the VDD pin to filter noise on the supply line. As the device is
ratiometric, any noise on the supply is coupled to the sensor output.
2019-04-29
User’s Manual4Rev. 1.0
TLE5501
R
TMR
GND
VDD
U_out
C
b
R
TMR
Ut()U01e–
t τ⁄–
()=
TMR-Based Angle Sensor
Transient behavior
2Transient behavior
For the sine and cosine output pins, it is also recommended to use a buffer capacitor Cb for filtering purpose.
As the device itself has a high output impedance, given by the TMR resistors R
a low-pass filter together with the bridge resistivity.
2.1Bandwidth of the TMR bridge
It has to be taken into account that the low pass filter limits the bandwidth of the sensor and increases step
response time. Figure 5 shows a schematic of the sensor output structure with an external capacitor C
resistivity of a TMR resistor R
is specified in the datasheet and has a value between 4kΩ and 8kΩ.
TMR
, this buffer capacitor builds
TMR
. The
b
Figure 5 Schematic of one branch of the TMR bridge with external buffer capacitor C
The result of a pSPICE simulation of this output structure is shown in Figure 6. A resistor of R
capacitor value of C
= 1nF is assumed. Applying a voltage step of 5V on the supply VDD is simulated. This is
b
b
= 8kΩ and a
TMR
compared with analytical simulations using below Equation (2.1):
(2.1)
The time constant for the bridge τ
is defined as: τbr = RC, U0 is taken to be 2.5V = VDD/2.
br
A good approximation of the transient behavior in the analytical calculation can be achieved with R = 4kΩ and
C
= 1nF, so R in the analytical simulation is half of the resistivity of one TMR resistor R
b
This behavior is equal to a low-pass filter at the sensor output with R = R
Figure 6 Simulation (pSPICE and analytical) of the RC behavior of the output voltage (R
= 1nF). Voltage step on V
. The 100nF capacitor on VDD is not included in the simulations
DD
= 8kΩ, Cb
TMR
The transient behavior when applying an AC magnetic field with frequency f is shown in Figure 7 and Figure 8.
The pSPICE simulation is compared with analytical calculations according to Equation (2.2) and
Equation (2.3) below. Again, a good fit is achieved using R = 4kΩ for the calculation.
(2.2)
(2.3)
User’s Manual6Rev. 1.0
2019-04-29
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