TDK5101F_07 INFINEON [Infineon Technologies AG], TDK5101F_07 Datasheet - Page 28

• Manufacturer Part Number: TDK5101F_07
• Description: 315 MHz ASK/FSK Transmitter in 10-pin Package
• Manufacturer: INFINEON [Infineon Technologies AG]

If the FSK switch is closed, Cv_ is equal to Cv1 (C1 in the application diagram). If the
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.
3.9
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 6
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=615.2 kHz
=
Csw
±
fCLKOUT
=
∗
CL
Cv
1
28
1
±
(
−
Cv
1
1
(
+
Cv
*
+
ω
8
)
+
2
−
*
)
L
CLD
Cv
∗
(
Cv
1
1
RL
+
Csw
[
kOhm
39
18
10
)
]
V 1.3, 2007-09-19
Applications
TDK5101F