TDA7705_10 Datasheet, PDF (35/42 Pages) STMicroelectronics – Highly integrated tuner for AM/FM car radio

TDA7705
Weak signal processing
5.1.5 High cut control
Table 30.
Symbol
High cut control
(continuous set)
Parameter
Test condition
Min
Typ
Max
minimum RF level for widest
HCFSsp Start point vs. field strength ^{HC filter (filter # 7)}
0
no multipath present
maximum RF level for
HCFSep End point vs. field strength narrowest HC filter (filter # 0) 0
no multipath present
Field strength-related
HCFStW2N transition time from wide to
narrow band
V_rf step-like variation from
60 dBµV to 10 dBµV
Field strength-related
HCFStN2W transition time from narrow to
wide band
V_rf step-like variation from
0 dBµV to 60 dBµV
(1)
HCMPsp Start point vs. multipath
minimum RF level for widest
HC filter (filter # 7)
equivalent 19 kHz AM
5
modulation depth;
field strength = 80 dBµV
HCMPep End point vs. multipath
maximum RF level for
narrowest HC filter (filter # 0)
equivalent 19 kHz AM
5
modulation depth;
field strength = 80 dBµV
Multipath -related transition
HCMPtN2W time from narrow to wide
band
V_rf step-like variation from
20 dBµV to 80 dBµV
0.001
HCMPtW2N
Multipath -related transition
time from wide to narrow
V_rf step-like variation from
80 dBµV to 20 dBµV
0.001
HCmaxBW
Maximum cut-off frequency of
high cut filter bank
Filter #7, -3 dB response
frequency, input signal with
pre-emphasis
HCmin
BW
HCminBW
Minimum cut-off frequency of
high cut filter bank
Filter #0, -3 dB response
frequency, input signal with
pre-emphasis
0.1
HCnumFilt Number of discrete HC filters -
-
50
30
(1)
14
10
30
0.001
0.001
14
3
8 ⁽³⁾
50
40
100
150 ⁽²⁾
150 ⁽²⁾
20
20
18
HCma
xBW
-
1. Depends only on field strength filter time constant.
2. Means that 100% equivalent 19 kHz AM modulation depth will not achieve full band narrowing.
3. Intermediate filters (#6 - #1) cut-off frequencies exponentially spaced between HCmaxBW and HCminBW.
Units
dBµV
dBµV
-
s
%
%
s
s
kHz
kHz
-
Doc ID 15938 Rev 8
35/42