TDA5250D2_07 INFINEON [Infineon Technologies AG], TDA5250D2_07 Datasheet - Page 56

• Manufacturer Part Number: TDA5250D2_07
• Description: ASK/FSK 868MHz Wireless Transceiver
• Manufacturer: INFINEON [Infineon Technologies AG]

3.2.3
For the correct calculation of the external capacitors the parasitic capacitances of the pins and the
switches (C
Figure 3-19
Table 3-2
With the given parasitics the actual C
Data Sheet
C vm
C v+
=
20
Name
Parasitics
C 20
C 21
C 22
, C
(
---------------------------------------------------------------------------------------------------------------------------------------- -
Typical values of parasitic capacitances
C
=
C v1
parasitics of the switching network
v1
21
(
-------------------------------------------------------------------------------------------------------
C
C v1
, C
+
+
v1
C
C tune1
22
tune1
C
+
+
v-
) have to be taken into account.
C
C
C
C tune1
tune1
V1
V2
=
)
+
⋅
C
(
C v2
v1
C
)
C
f, C
+
v2
⋅
V3
+
(
C v2
C
+
L
C
+
v2
C 20
tune1
C
XSWA 22
XOUT 19
XSWF 20
XGND 23
+
20
+
v
XIN 21
C 20
+
can be calculated:
C
+
20
C
+
C
FSK-: 2,8 pF / FSK+&ASK: 2.3pF
v3
+
C
v3
+
21
C
C
+
+
tune2
tune2
C 22
C
56
22
C
22
L
+
+
)
C
+
C
tune2
tune2
C
C 21
4,5 pF
1,3 pF
21
Value
-R
)
C
+
20
C 21
C
C
tune2
tune1
[3 – 24]
[3 – 26]
TDA5250 D2
Version 1.7
QOSC_parasitics.wmf
Application
2007-02-26