TDA5252G2 Datasheet, PDF (56/86 Pages) Infineon Technologies AG – ASK/FSK 915MHz Wireless Transceiver

3.2.7 Chip and System Tolerances
Quartz: fp=19.0625MHz; C1=8fF; C0=2.1pF; CL=20pF (typical values)
Cv1=8.2pF, Cv2=6.8pF, Cv3=22pF
TDA5252 G2
Version 1.1
Application
Table 3-7
Internal Tuning
Part
Frequency set accuracy
Temperature (-40...+85C)
Supply Voltage(2.1...5.5V)
Total
Frequency tolerance
@ 915MHz
+/- 1.5kHz
+/- 5kHz
+/- 1.5kHz
+/- 8kHz
Rel. tolerance
+/- 1.6ppm
+/- 6ppm
+/- 1.5ppm
+/- 9ppm
Table 3-8 Default Setup (without internal tuning & without Pin21 usage)
Part
Frequency tolerance Rel. tolerance
@ 915MHz
Internal capacitors (+/- 10%)
+/- 4kHz
+/- 4.5ppm
Inductivity of the crystal oscillator
+/- 29kHz
+/- 33ppm
Temperature (-40...+85C)
+/- 5kHz
+/- 6ppm
Supply Voltage (2.1...5.5V)
+/- 1kHz
+/- 1.5ppm
Total
+/- 39kHz
+/- 45ppm
Tolerance values in Table 3-8 are valid, if pin 21 is not connected. Establishing the connection to
pin 21 the tolerances increase.
Concerning the frequency tolerances of the whole system also crystal tolerances (tuning
tolerances, temperature stability, tolerance of CL) have to be considered.
In addition to the chip tolerances also the crystal and external component tolerances have to be
considered in the tuning and non-tuning case.
In case of internal tuning: The crystal on the evaluation board has a temperature stability of +/-
20ppm (or +/- 18kHz of the RF), which must be added to the total tolerances.
In case of default setup (without internal tuning and without usage of pin 21) the temperature
stability and tuning tolerance of the crystal as well as the tolerance of the external capacitors (+/-
0.1pF) have to be added. The crystal on the evaluation board has a temperature stability of +/-
20ppm (means +/- 18kHz of the RF) and a tuning tolerance of +/- 10ppm (means +/- 9kHz of the
RF). The external capacitors add a tolerance of +/- 3.5ppm (or +/- 3.2kHz regarding to the RF).
The frequency stabilities of both the receiver and the transmitter and the modulation bandwidth set
the limit for the bandwidth of the IQ filter. To achieve a high receiver sensitivity and efficient
Data Sheet
56
2007-02-26