TDK5100F_08 INFINEON [Infineon Technologies AG], TDK5100F_08 Datasheet - Page 27

• Manufacturer Part Number: TDK5100F_08
• Description: 434 MHz ASK/FSK Transmitter in 10-pin Package
• Manufacturer: INFINEON [Infineon Technologies AG]

The value of Cv± can be calculated as
If the FSK switch is closed, Cv
FSK switch is open, Cv2 (C2 in the application diagram) can be calculated.
Csw:
Remark:
on the layout also and must be adapted for the specific application board.
3.8
The CLKOUT pin is an open collector output. An external pull up resistor (RL) should be
connected between this pin and the positive supply voltage. The value of RL is
depending on the clock frequency and the load capacitance CLD (PCB board plus input
capacitance of the microcontroller). RL can be calculated to:
Table 7
Remark:
Data Sheet
parallel capacitance of the FSK switch (3 pF incl. layout parasitics)
These calculations are only approximations. The necessary values depend
Design Hints on the Clock Output (CLKOUT)
Clock Output
To achieve a low current consumption and a low
spurious radiation, the largest possible RL should be chosen.
CL
10
20
[
5
pF
Cv
]
2
=
C
2
RL
-
=
Cv
fCLKOUT=847.5 kHz
is equal to Cv1 (C1 in the application diagram). If the
=
Csw
±
fCLKOUT
=
∗
Cv
CL
1
27
1
±
(
−
Cv
1
1
(
+
Cv
*
+
ω
8
)
+
2
−
*
)
L
CLD
Cv
∗
(
Cv
1
1
RL
+
Csw
[
kOhm
6.8
27
12
)
]
V 1.2, 2008-04-04
Applications
TDK5100F