TDA5204E1 Datasheet, PDF (25/40 Pages) Infineon Technologies AG – ASK Single Conversion Receiver 390MHz

TDA 5204 E1
preliminary
Applications
4.4 Quartz Frequency Calculation
The quartz frequency is calculated by using the following formula:
ƒ_QU = (ƒ_RF ± 10.7MHz) / r
(1),
with
ƒ_RF .... receive frequency
+/- ... high-side / low-side injected
ƒ_LO ....
ƒ_QU ....
r ....
local oscillator (PLL) frequency (ƒ_RF ± 10.7)
quartz oscillator frequency
ratio of local oscillator (PLL) frequency and quartz
frequency as shown in the subsequent table.
Table 4-1
frequency range
f_RF
385...406MHz
406...428MHz
781...823MHz
803...844MHz
high-side
injected
X
X
low-side
injected
X
X
FSEL
Pin11
open
open
GND
GND
Table 4-2
quartz crystal
range
6.xx MHz
12.xx MHz
CSEL
Pin16
open
GND
Example:
f_RF=390MHz
Table 4-3
FSEL
open
open
GND
GND
CSEL
open
GND
open
GND
Ratio r
(f_LO/f_QU)
64
32
128
64
f_QU=(390MHz+10.7MHz) / 64 = 6.2609375MHz
f_QU=(390MHz+10.7MHz) / 32 = 12.521875MHz
Wireless Components
4-6
Specification, January 2001