TDA5220XT Infineon Technologies, TDA5220XT Datasheet - Page 24

• Manufacturer Part Number: TDA5220XT
• Manufacturer: Infineon Technologies

Specifications of TDA5220XT

• Operating Temperature (min): -40C
• Operating Temperature (max): 125C
• Operating Temperature Classification: Automotive
• Product Depth (mm): 4.4mm
• Product Length (mm): 9.7mm
• Operating Supply Voltage (min): 4.5V
• Operating Supply Voltage (typ): 5V
• Operating Supply Voltage (max): 5.5V
• Lead Free Status / Rohs Status: Compliant

3.5
The threshold of the data slicer can be generated using an external R-C integrator as
shown in Figure 7.
The time constant T
(see Figure 9) has to be significantly larger than the longest period of no signal change
T
In order to keep distortion low, the minimum value for R is 20k .
T
R1, R
Figure 7
In case of ASK operation another possibility for threshold generation is to use the peak
detector in connection with an internal resistive divider and one capacitor as shown in
the following Figure 8. For selecting the peak detector as reference for the slicing level
a logic low as to be applied on the SSEL pin.
In case of MSEL is high (or open), which means that ASK-Mode is selected, a logic low
on the SSEL pin yields a logic high on the AND-output and thus the peak-detector is
selected (see Figure 9).
In case of FSK the MSEL-pin and furthermore the one input of the AND-gate is low, so
the peak detector can not be selected.
The capacitor value is depending on the coding scheme and the protocol used.
Preliminary Specification
L
A
T
T
and
within the data sequence.
has to be calculated as
A
A
F3 int
R
R
R
1
1
1
, R
(
Data Slicer Threshold Generation
R
R
R
F4 int
R
1
F
F
Data Slicer Threshold Generation with External R-C Integrator
F
3
3
3
int
R
int
int
and C13 see also Figure 7 and .Figure 9
F
4
data
filter
int
A
R
R
R
of this circuit including also the internal resistors R
F
F
F
4
4
4
int
int
int
)
19
C
C
13
13
20
R
R
1
1
U
24
II
II
threshold
data slicer
(
(
R
R
CM
F
F
3
3
int
int
v
25
R
R
F
F
4
4
int
int
)
)
C
C
13
13
V 1.1, 2004-10-20
F3int
Applications
...
...
TDA 5220
for
for
and R
FSK
ASK
F4int