TDA7421 Datasheet, PDF (9/38 Pages) STMicroelectronics – AM/FM TUNER FOR CAR RADIO AND Hi-Fi APPLICATIONS

TDA7421
ELECTRICAL CHARACTERISTICS (continued)
Detuning Detector
Ref: FM Test Circuit, measure:
- Inputs at VFMLIMIN, CW
- output at VMUTE,DRIVE
Symbol
DDSTART
Parameter
Detuning Detector Starting Point
DDSLOPE,MIN Detuning Detector Minimum
Muting Slope
DDSLOPE,MAX Detuning Detector Maximum
Muting Slope
DDTRC
Detuning Detector Time Constant
Ratio
Test Condition
frequency shift from 10.7MHz at
which VMUTE,DRIVE = VPLAY
frequency shift from 10.7MHz +
DDSTART, at which VMUTE,DRIVE =
VMUTE, BWM2-0 set to 100,
FMRECSEEK set to 0
frequency shift from 10.7MHz +
DDSTART, at which VMUTE,DRIVE =
VMUTE, BWM2-0 set to 001,
FMRECSEEK set to 0
ratio of "reception" mode
integration time constant inside the
Detuning Detector with respect to
"seek" mode
Min.
22.5
7.5
Typ.
±23
30
10
34/6
Max.
37.5
12.5
Unit
KHz
KHz
KHz
s/s
Adjacent Channel Detector
Ref: FM Test Circuit, measure:
- Inputs at VFMLIMIN: desired 10.7MHz, 95dBu CW; undesired 10.8MHz CW
- output at VMUTE,DRIVE
- BWM2-0 set to 001
Symbol
ACDMAX
ACDMIN
Parameter
Adjacent Channel Quality Detector
Maximum Sensitivity Threshold
Adjacent Channel Quality Detector
Minimum Sensitivity Threshold
Test Condition
amplitude of undesired signal at
which VMUTE,DRIVE = VMUTE,
HDM4-0 set to 11111
amplitude of undesired signal at
which VMUTE,DRIVE = VMUTE,
HDM4-0 set to 00000
Min. Typ. Max. Unit
91
dBu
94.8
dBu
Field Strength Station Detector
Ref: FM Test Circuit, measure:
- Inputs at VFMLIMIN: desired 10.7MHz, CW
- output at VFMSD
- FMRECSEEK set to 1
Symbol
FSSDMIN
FSSDMAX
Parameter
Field Strength Station Detector
Minimum Threshold
Field Strength Station Detector
Maximum Threshold
Test Condition
VFMLIMIN level at which
VFMSD = 2.5, FSM4-0 set to 00000
VFMLIMIN level at which
VFMSD = 2.5, FSM4-0 set to 11111
Min.
Typ.
24
76
Max.
Unit
dBu
dBu
Detuning Station Detector
Ref: FM Test Circuit, measure:
- Input at VFMLIMIN, CW;
- output at VFMSD
- FMRECSEEK set to 1
Symbol
DSD
Parameter
Detuning Station Detector
Threshold
Test Condition
frequency shift from 10.7MHz at
which VFMSD = 2.5V
Min. Typ. Max. Unit
23
KHz
9/38