TDA5230 Datasheet, PDF (33/186 Pages) Infineon Technologies AG – Universal Low Power ASK/FSK Single Conversion Multi-Channel Image-Reject Receiver

TDA523x
Functional Description
Based on the tri-modulus divider concept, up to 17 distinct channels¹⁾ are accessible
within the selected operational frequency band by utilizing the same reference crystal
frequency. The selected LO-frequency is described by the formula:
fLO
=
f--s--R--y---s-- _{⋅ (256 ⋅ R + S) ⋅ 4-----1⋅---A---}
=
4-f-s---⋅^-y--A-s--
⋅


256
+
S_{R---}
Values for A depend on the frequency band: 302...320MHz...A=3 (TDA5231),
433...450MHz...A=2, 865...870MHz...A=1 (TDA5230)
Values for S are +1, 0, -1
Values for R are 1,2,3,4,5,6,7,8
Example:
A system for 433.92 MHz, having an f_sys=13.225625MHz has following available sub-
channels:
S
R
1
1
1
2
1
3
1
4
1
5
1
6
1
7
1
8
0
2
-1
8
-1
7
-1
6
-1
5
-1
4
-1
3
f_RF [MHz]
435.573
434.747
434.471
434.333
434.251
434.196
434.156
434.127
433.92
433.713
433.684
433.644
433.589
433.507
433.369
1) Channels with receive frequencies close to the harmonics of the reference crystal frequency should not be
used in applications.
Data Sheet
29
Version 4.0, 2007-06-01