TDA7116F Infineon Technologies, TDA7116F Datasheet - Page 22

• Manufacturer Part Number: TDA7116F
• Description: IC TX ASK/FSK 868MHZ 10-TSSOP
• Manufacturer: Infineon Technologies

Specifications of TDA7116F

• Frequency: 866MHz ~ 870MHz
• Modulation Or Protocol: ASK, FSK
• Power - Output: 13dBm
• Current - Transmitting: 14.2mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Voltage - Supply: 2.1 V ~ 4 V
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 10-TSSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Applications: -
• Memory Size: -
• Data Rate - Maximum: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: SP000611114

3.4
Application Hints on the crystal oscillator
The crystal oscillator achieves a turn on time less than 1 msec when the specified crystal
is used. To achieve this, a NIC oscillator type is implemented in the TDA7116F. The input
impedance of this oscillator is a negative resistance in series to an inductance. Therefore
the load capacitance of the crystal CL (specified by the crystal supplier) is transformed
to the capacitance Cv.
Figure 11
Formula 1:
CL:
ω:
L:
Example for the ASK-Mode:
Referring to the application circuit, in ASK-Mode the capacitance C2 is replaced by a
short to ground. Assume a crystal frequency of 13.56MHz and a crystal load capacitance
of CL = 12 pF. The inductance L at 13.56MHz is about 4.6 μH. Therefore C1 is calculated
to 10 pF.
But please note that the calculated Cv value includes all parasitic. So, the value of the
capacitor (except the parasitic) is a bit smaller depending on the parasitic.
Data Sheet
crystal load capacitance for nominal frequency
angular frequency
inductance of the crystal oscillator
Application Hints on the Crystal Oscillator
Application Hints
-R
Cv
Cv
=
L
IC
CL
=
1
CL
1
+
22
1
ω
+
1
2
ω
L
f, CL Cv
2
L
=
C
1
V 1.0, 2009-03-05
Applications
TDA7116F