STLC60134S
ATU-R RX Filters
The integrated filter have the following characteristics:
Table 6. Integrated HC Filter Characteristics
Description
Input referred noise
Max. input level
Max. output level
Type
Frequency band
Frequency tuning
Max. in-band ripple
Matlab Model
Default cut off frequency @ -3dB
Actual cut off @ -3dB
HC Freq. selection register
100nVHz-1/2
Value/Unit
1Vpd
1Vpd
3rd order butterworth
1.104MHz (0%setting, see below)
-43.75% -> +0%
1dB
[B, A] = butter (3, w0, ’s’)
F0 = 1560KHz
w0 = 2 * pi * F0/((20 + n)/16)
n = -4,..,3
see (AFE settings ,Table 22)
Table 7. Phase Characteristic
Description
Total RX filter group delay
TotalRX filter group delay distortion
Value/Unit
< 50µs @ 138kHz < f < 1.104MHz
< 15µs @ 138kHz < f < 1.104MHz
Figure 7. HC Filter Mask for ATU-R RX and ATU-C TX
AMPLITUTDE
+/-1dB
0dB
5dB 36dB 50dB
30
D98TL360
1104 2208 7728 16560
kHz
Note: The total ATU_R RX path (including ADC) group delay distortion is 16µs (i.e. = 15µs + 1µs of ADC)
ATU-C RX filter
This filter is the same as the one used for ATU-R TX.
Linearity of RX
Linearity of the RX analog path is defined by the IM3 product of two sinusoidal signals with frequencies
f1 and f2 and each with 0.5Vpd amplitude (total ≤ 1Vpd) at the output of the RX - AGC amplifier (i.e: be-
fore the ADC) for the case of minimal AGC setting.
The following tables 8 and 9 list the RX path intermodulation distortion (as S/IM3 ratio) in downstream
and upstream bandwidth.
Table 8. Linearity of ATU-R RX
f1 (0.5Vpd)
f2 (0.5Vpd)
S/IM3 (AGC = 0dB)
300kHz
200kHz
59.5dB @ 100kHz
53.5dB @ 400kHz
43.5dB @ 700kHz
42.5dB @ 800kHz
500kHz
400kHz
59.5dB @ 300kHz
48.0dB @ 600kHz
700kHz
600kHz
48.0dB @ 500kHz
42.5dB @ 800kHz
8/22