STMICROELECTRONICS TDA7541

TDA7541
AM/FM car radio tuner IC with stereo decoder
and intelligent selectivity system
Features
■
FM part
– AGC generation by RF and IF detection
– I/Q mixer for 1st IF 10.7MHz with image
rejection
– Mixer for 2nd IF 450kHz
– Internal 450kHz band pass filter with
bandwidth control by ISS
– Fully integrated FM demodulator with noise
cancellation
■
AM part
– Wide and narrow AGC generation
– Mixer for 1st IF 10.7MHz, AM upconversion
– Mixer for 2nd IF 450kHz
– Integrated AM-demodulator
– AM IF noise blanking
■
Stereo decoder
– PLL with adjustment free, fully integrated
VCO
– Automatic pilot dependent
MONO/STEREO switching
– Programmable ROLL-OFF compensation
– High cut and stereo blend-characteristics
programmable
– Dedicated RDS mute
– Audio noise blanker
■
Additional features
– VCO for world tuning range
Table 1.
LQFP64
– High performance fast PLL for RDSSystem
– IF counter for FM and AM with search stop
signal
– Quality detector for level, deviation,
adjacent channel and multipath
– ISS (Intelligent selectivity system) for
cancellation of adjacent channel and noise
influences
– Adjacent channel mute
– Fully electronic alignment
– Independend weather band input
– All functions I2C bus controlled
Description
The TDA7541 is a high performance tuner circuit
with stereo decoder for AM/FM car radio. It
contains a mixer, IF amplifier, demodulator for AM
and FM, stereo decoder, quality detection, ISS
filter and PLL synthesizer with IF counter on a
single chip. Use of BICMOS technology allows the
implementation of several tuning functions and a
minimum of external components.
Device summary
Order code
Package
Packing
TDA7541
LQFP64 (10 x 10 x 1.4mm)
Tray
TDA7541TR
LQFP64 (10 x 10 x 1.4mm)
Tape and reel
TDA7541W
LQFP64 (14 x 14 x 1.4mm)
Tray
TDA7541WTR
LQFP64 (14 x 14 x 1.4mm)
Tape and reel
January 2008
Rev 3
1/76
www.st.com
1
Contents
TDA7541
Contents
1
Block circuit diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2
Pin connection and pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3
4
2.1
Pin connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.2
Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Electrical specifications and characteristics . . . . . . . . . . . . . . . . . . . . 10
3.1
Thermal data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.2
Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.3
Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
4.1
Mixer 1 AGC and IF amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
4.1.2
Mixer2, limiter, FM demodulator and spike cancellation . . . . . . . . . . . . 27
4.1.3
Quality detection and ISS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
4.1.4
Block diagram quality detection principle . . . . . . . . . . . . . . . . . . . . . . . . 30
4.1.5
Weak signal mute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
4.1.6
Weather band input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
AM section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
4.3
Stereo decoder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
4.5
4.3.1
Decoder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
4.3.2
Noise blanker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
4.3.3
Functional description of the multipath detector . . . . . . . . . . . . . . . . . . 37
4.3.4
Quality detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
4.3.5
AFS control and stereo decoder mute . . . . . . . . . . . . . . . . . . . . . . . . . . 37
PLL and IF counter section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
4.4.1
PLL frequency synthesizer block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
4.4.2
IF counter block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
I2C bus interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Software specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
5.1
2/76
4.1.1
4.2
4.4
5
FM part . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Address organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
TDA7541
Contents
5.2
Control register function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
5.3
Data byte specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
6
Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
7
Preliminary application circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
8
Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
9
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
3/76
List of tables
TDA7541
List of tables
Table 1.
Table 2.
Table 3.
Table 4.
Table 5.
Table 6.
Table 7.
Table 8.
Table 9.
Table 10.
Table 11.
Table 12.
Table 13.
Table 14.
Table 15.
Table 16.
Table 17.
Table 18.
Table 19.
Table 20.
Table 21.
Table 22.
Table 23.
Table 24.
Table 25.
Table 26.
Table 27.
Table 28.
Table 29.
Table 30.
Table 31.
Table 32.
Table 33.
Table 34.
Table 35.
Table 36.
Table 37.
Table 38.
Table 39.
Table 40.
Table 41.
Table 42.
4/76
Device summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Thermal data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Globals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
FM section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
AM section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Stereo decoder section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
PLL section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
ISS filter control by I2C bus. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Internal ISS control signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
ISS control modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Address organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
I2C control bit description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Subaddress description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Addr 0 TPLL charge pump control (0Bh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Addr 1 TPLL Counter 1 (LSB). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Addr 2 TPLL Counter 2 (MSB) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Addr 3 TV(00h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Addr 4 TV/IF Counter (FM ACh , AM 1Ch) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Addr 5 TPLL Divider (FM 3Dh , AM 2Dh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Addr 6 AGC (FM 06h, AM 2Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Addr 7 Quality AC (FM 50h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Addr 8 Quality ACM/MP (FM 6Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Addr 9 Quality Dev (FM 49h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Addr 10 Quality MUX/FSU (FM 0Eh , AM 0Fh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Addr 11 Weak Signal Mute (FM A8h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Addr 12 AM IF NB (AM B1h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Addr 13 XTAL adjust(80h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Addr 14 IF2 adjust (FM E8h, AM 08h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Addr 15 IQ adjust / Switch (FM E7h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Addr 16 FM keying AGC (FM 1Dh). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Addr 17 Roll off / Level gain (77h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Addr 18 SD Stereoblend / AM corner frequency (0Dh) . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Addr 19 SD High cut (2Fh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Addr 20 SD MP (FM 97h, AM 3Fh). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Addr 21 SD Quality (FFM 7Ah, AM FAh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Addr 22 SD NB I (FM 05h, AM 04h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Addr 23 SD NB II (FM E2h, AM C2h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Addr 24, 26, 27, 28, 29 testing (FEh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Addr 25 Testing (FEh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
TDA7541
List of figures
List of figures
Figure 1.
Figure 2.
Figure 3.
Figure 4.
Figure 5.
Figure 6.
Figure 7.
Figure 8.
Figure 9.
Figure 10.
Figure 11.
Figure 12.
Figure 13.
Figure 14.
Figure 15.
Figure 16.
Block circuit diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Pin connections (top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Programming of HC filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Programming of stereo blend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Adaptive threshold control of noise blanker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Stereo blend controlled threshold adjust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Deviation controlled threshold adjust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Block diagram FM part . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Block diagram VCO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Block diagram ISS function. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Block diagram AM path. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Block diagram stereo decoder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Block diagram audio noise blanker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Block diagram multi path detection for stereo decoder. . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
Application circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
LQFP64 mechanical data and package dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
5/76
Block circuit diagram
1
Block circuit diagram
Figure 1.
6/76
TDA7541
Block circuit diagram
TDA7541
Pin connection and pin description
2
Pin connection and pin description
2.1
Pin connections
GNDVCC2
MIX2AMPOUT
VCC2
MIX2REF
MIX2OUT
AMRFAGCTC
MIX2INREF
MIX2IN
AMAGC2TC
IF1REF
IF1AMPOUT
VCCIF1
IF1AMPIN
GNDIF
MIX1REF
Pin connections (top view)
MIX1OUT
Figure 2.
64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49
2.2
48
VREF1
2
47
AMIF2IN
AMMIX1IN
3
46
GNDDEM
AMRFAGCOUT
4
45
FMREFDEMC
WB
5
44
AMIF2REF
AMMIX1RAF
6
43
MPXOUT
AMPINDR
7
42
MUTETC
FMMIX1IN1
8
41
MPXIN
GNDRF
9
40
AMREFDEMC
FMMIX1IN2
10
39
MPTC
TV
11
38
GNDSTD
FMPINDR
12
37
FSWO
FMAGCTC
13
36
VCC1
VCOB
14
35
R
VCOE
15
34
L
VCCVCO
16
33
GNDVCC1
XTALD
ISSTC2
ISSTC1
XTALG
FSTC
FSU
SCL
SDA
SSTOP
SW
LPF
LPHC
VREF2
23 24 25 26 27 28 29 30 31 32
LPOUT
17 18 19 20 21 22
MUX
1
DEVTC
GNDVCO
VCCMIX1
Pin description
Table 2.
Pin description
Pin No.
Pin name
Function
1
VCCMIX1
Mixer1 Supply
2
DEVTC
Deviation Detector Time Constant
3
AMMIX1IN
AM Mixer1 Input
4
AMRFAGCOUT
AM RF AGC Voltage Output
7/76
Pin connection and pin description
Table 2.
Pin description (continued)
Pin No.
8/76
TDA7541
Pin name
Function
5
WB
Weather Band Input
6
AMMIX1REF
AM Mixer1 Reference
7
AMPINDR
AM Pin Diode Driver Output
8
FMMIX1IN1
FM Mixer1 Input1
9
GNDRF
RF Ground
10
FMMIX1IN2
FM Mixer1 Input2
11
TV
Tuning Voltage Preselection
12
FMPINDR
FM Pin Diode Driver Output
13
FMAGCTC
FM AGC Time Constant
14
VCOB
VCO Input Base
15
VCOE
VCO Output Emitter
16
VCCVCO
VCO Supply
17
GNDVCO
VCO Ground
18
LPOUT
OpAmp Output to PLL Loop Filter
19
VREF2
Voltage Reference for PLL OpAmp
20
LPF
OpAmp Input to PLL Loop Filter
21
LPHC
High Current PLL Loop Filter Input
22
SW
Free Programmable Switch Output
23
MUX
Multiplexer Output
24
SSTOP
Search Stop Output
25
SDA
I2C Bus Data
26
SCL
I2C Bus Clock
27
FSU
Unweighted Field Strength Output
28
FSTC
S-meter Filtering Capacitor
29
XTALG
Xtal Oscillator to MOS Gate
30
ISSTC1
ISS Filter Time Constant1 (slow)
31
ISSTC2
ISS Filter Time Constant2 (fast)
32
XTALD
Xtal Oscillator to MOS Drain
33
GNDVCC1
Digital Ground
34
L
Stereo Decoder Output Left
35
R
Stereo Decoder Output Right
36
VCC1
Digital Supply
37
FSWO
Weighted Field Strength Output
38
GNDSTD
Stereo Decoder Ground
39
MPTC
Multipath Detector Time Constant
TDA7541
Pin connection and pin description
Table 2.
Pin description (continued)
Pin No.
Pin name
Function
40
AMREFDEMC
AM Demodulator Reference
41
MPXIN
Stereo Decoder Input
42
MUTETC
Weak Signal Mute Time Constant
43
MPXOUT
AM Audio / MPX Output
44
AMIF2REF
AM IF2 Amplifier Reference Voltage
45
FMREFDEMC
FM Demodulator Reference
46
GNDDEM
FM Demodulator Ground
47
AMIF2IN
AM IF2 Amplifier Input
48
VREF1
5V Reference
49
GNDVCC2
Analog Ground
50
MIX2AMPOUT
MIXER2 Amplifier Output
51
VCC2
Analog Supply
52
MIX2REF
Mixer2 Reference
53
MIX2OUT
Mixer2 Output
54
AMRFAGCTC
AM RF AGC Time Constant
55
MIX2INREF
Mixer2 Input Reference
56
MIX2IN
Mixer2 Input
57
AMAGC2TC
AM AGC2 Time Constant
58
IF1REF
IF1 Amplifier Reference
59
IF1AMPOUT
IF1 Amplifier Output
60
VCCIF1
IF1 Supply
61
IF1AMPIN
IF1 Amplifier Input
62
GNDIF1
IF1 Ground
63
MIX1REF
Mixer1 Reference
64
MIX1OUT
Mixer1 Output
9/76
Electrical specifications and characteristics
TDA7541
3
Electrical specifications and characteristics
3.1
Thermal data
Table 3.
Thermal data
Symbol
Parameter
RTH(j-amb) Thermal resistance junction to ambient
3.2
Max.
Value
Unit
70
°C/W
Absolute maximum ratings
Table 4.
Absolute maximum ratings
Symbol
VS
Parameter
Conditions
Supply voltage
Value
Unit
9.5
V
Tamb
Ambient temperature
-40 to 85
°C
Tstg
Storage temperature
-55 to +150
°C
2
kV
Machine Model
100
V
Charged Device Model
300
V
Human Body Model
VESD
ESD withstand voltage
3.3
Electrical characteristics
Table 5.
Globals
(Tamb = 25°C, VCC1 = VCC2 = VCCMIX1 = VCCVCO = VCCIF = 8.5V, fXtal = 10.25 MHz,
in application circuit, unless otherwise specified)
Item
Symbol
Parameter
Test conditions
Min.
Typ.
Max.
Unit
1. Supply
1.1
VCC1
Digital Supply Voltage
7.7
8.5
9
V
1.2
VCC2
Analog Supply Voltage
7.7
8.5
9
V
1.3
VCCVCO
VCO Supply Voltage
7.7
8.5
9
V
1.4
VCCMIX1
Mixer1 Supply Voltage
7.7
8.5
9
V
1.5
VCCIF
IF1 Supply Voltage
7.7
8.5
9
V
1.6
ICC1
Supply Current
FM ON
19
23
mA
1.7
ICC1
Supply Current
AM ON
21
25
mA
1.8
ICC2
Supply Current
FM ON
48
58
mA
1.9
ICC2
Supply Current
AM ON
37
44
mA
1.10
ICCVCO
Supply Current
12
15
mA
1.11
ICCMIX1
Supply Current
32
40
mA
10/76
FM ON
TDA7541
Table 5.
Item
Electrical specifications and characteristics
Globals (continued)
(Tamb = 25°C, VCC1 = VCC2 = VCCMIX1 = VCCVCO = VCCIF = 8.5V, fXtal = 10.25 MHz,
in application circuit, unless otherwise specified)
Symbol
Parameter
1.12
ICCMIX1
Supply Current
1.13
ICCIF
Supply Current
Test conditions
Min.
AM ON
Typ.
Max.
Unit
20
24
mA
4
5
mA
2. Reference voltages
2.1
VREF1
Internal reference voltage
IREF1 = 0mA
4.8
5
5.2
V
2.2
VREF2
Internal reference voltage
IREF2 = 0mA
2.4
2.5
2.6
V
3. I2C bus interface
3.1
fSCL
Clock frequency
400
kHz
3.2
VIL
Input low voltage
1
V
3.3
VIH
Input high voltage
3
3.4
IIN
Input current
-5
3.5
VO
Output acknowledge voltage
Table 6.
Item
V
IO = 1.6mA
5
µA
0.4
V
FM section
(Tamb = 25°C, VCC1 = VCC2 = VCCMIX1 = VCCVCO = VCCIF = 8.5V, fXtal = 10.25 MHz,
fRF = 98MHz, dev = 40 kHz, fMod = 1 kHz, in application circuit, unless otherwise specified)
Symbol
Parameter
Test conditions
Min.
Typ.
Max.
Unit
4. Wide band RF AGC
4.1
V8-10
Lower threshold start
V13 = 2.5V,RFK “0”
79
dBμV
4.2
V8-10
Upper threshold start
V13 = 2.5V,RFK”0”
93
dBμV
4.3
Δ V8-10
Control range RF KAGC
KAGC”000”,RFAGC”00”,
V37 = 3.0….3.7V, RFK”1”
5
8
11
5. Narrow band IF & keying AGC
5.1
V61
Lower threshold start
KAGC = off, V8-10 = 0mVRMS
82
dBµV
5.2
V61
Upper threshold start
KAGC = off, V8-10 = 0mVRMS
94
dBµV
5.3
V61
Max. IFAGC threshold
with KAGC
KAGC”000”,IFAGC”00”,
V37 = 3.0V
97
dBµV
5.4
V37
Start point KAGC
KAGC”000”,IFAGC”00”,
3.2
3.4
3.6
V
5.5
Δ V61
Control range IF KAGC
KAGC”000”,IFAGC”00”,
V37 = 3.2….3.9V
12
15
18
dB
VREF1
+VBE
V
0.5
V
-17.5
µA
6. AGC time constant output
6.1
V13
Max. AGC output voltage
V8-10= 0mVRMS
6.2
V13
Min. AGC output voltage
V8-10 = 100mVRMS
6.3
I13
Min. AGC charge current
V8-10= 0mVRMS,V13 = 2.5V
-33
-25
11/76
Electrical specifications and characteristics
Table 6.
TDA7541
FM section (continued)
(Tamb = 25°C, VCC1 = VCC2 = VCCMIX1 = VCCVCO = VCCIF = 8.5V, fXtal = 10.25 MHz,
fRF = 98MHz, dev = 40 kHz, fMod = 1 kHz, in application circuit, unless otherwise specified)
Item
Symbol
6.4
I13
Parameter
Max. AGC discharge
current
Test conditions
Min.
Typ.
Max.
Unit
V8-10 = 100mVRMS,V13 = 2.5V
1.7
2.5
3.3
mA
15
25
35
µA
-16
mA
12
kΩ
7. AGC PIN diode driver output
7.1
I12
AGC OUT, current min.
V8-10 = 0mVRMS, V12 = 2.5V
7.2
I12
AGC OUT, current max.
V8-10 = 50 mVRMS, V12 = 2.5V
8. FM I/Q Mixer1 (10.7MHz)
8.1
RIN
Input resistance
Differential
8
10
8.2
CIN
Input capacitance
Differential
8.3
ROUT
Output resistance
530
660
790
Ω
8.4
V8,11
Input DC bias
2.2
2.5
2.8
V
8.5
G
Gain
Unloaded
20
22
24
dB
8.6
Gl
Gain
With 330Ω load
14
16
18
dB
8.7
INOISE
Equivalent input noise
8.8
CP1dB
1dB compression point
4
Referred to diff. mixer input
rd
pF
3
nV/√Hz
100
dBµV
119
dBµV
8.9
IIP3
3 order intermodulation
8.10
IQP
I/Q phase adjust
PH
-7
8.11
IRR
Image rejection ratio
Ratio wanted/image
30
40
dB
8.12
IRR
Image rejection ratio
With phase adjust
40
46
dB
Single ended
7
10
13
kΩ
530
660
790
Ω
2
2.3
2.6
V
24
26
28
dB
+8
DEG
9. WB I/Q Mixer1 (10.7MHz)
Input resistance
9.1
RIN
9.2
ROUT
9.3
V5
Input dc bias
9.4
G
Gain
unloaded
9.5
INOISE
Equivalent Input noise
Source impedance 400Ω
9.6
IIP3
Output resistance
rd
3 order intermodulation
2.3
nV/√Hz
113
dBµV
10. IF1 amplifier (10.7MHz)
RIN
Input resistance
10.2
CIN
Input capacitance
2.5
pF
10.3
V61
DC input voltage
VCCIF1/3
V
10.4
ROUT
Output resistance
10.5
COUT
Output capacitance
10.6
V59
DC output voltage
10.7
Gmin
Min. gain
12/76
265
265
IFG
330
330
396
Ω
10.1
396
Ω
2.5
pF
VCCIF1/2
V
9
dB
TDA7541
Table 6.
Electrical specifications and characteristics
FM section (continued)
(Tamb = 25°C, VCC1 = VCC2 = VCCMIX1 = VCCVCO = VCCIF = 8.5V, fXtal = 10.25 MHz,
fRF = 98MHz, dev = 40 kHz, fMod = 1 kHz, in application circuit, unless otherwise specified)
Item
Symbol
10.8
Gmax
10.9
10.10
10.11
Parameter
Test conditions
Min.
Typ.
Max.
Unit
Max. gain
IFG
21
dB
INOISE
Equivalent input noise
voltage
Gmax , Rgen=330Ω, RL=330Ω,
noise of Rgen not included
3.2
nV/√Hz
CP1dB
1dB compression point
referred to 330Ω input, Gmax
99
dBµV
referred to 330Ω input, Gmax
130
dBµV
IIP3
rd
3 order Intermodulation
11. Mixer2 (450kHz)
Ω
11.1
RIN
Input resistance
11.2
CIN
Input capacitance
11.3
V55.56
DC input voltage
3.7
11.4
ROUT
Output resistance
100
11.5
COUT
Output capacitance
11.6
V52,53
DC output voltage
11.7
gm
Conversion
transconductance
WB Mode; referred to MIX2OUT
126
µA/V
11.8
G
Gain
FM Mode, referred to MIX2OUT
14
dB
11.9
Cstep
Min. cap. Step
IF2A
2.2
pF
11.10
Cmax
Max. cap.
IF2A
33
pF
11.11
INOISE
Equivalent input noise
voltage,
including buffer mixer2
Rgen=330Ω, IF2Q”10”
noise of Rgen not included
15
nV/√Hz
11.12
CP1dB
1dB compression point
referred to 330Ω input ,IF2Q”10”
116
dBμV
referred to 330Ω input ,IF2Q”10”
132
dBμV
0.1
11.13
IIP3
rd
3 order Intermodulation
Differential
240
300
360
2.5
4
pF
4.3
kΩ
2.5
3.7
V
4
pF
4.3
V
12. Demodulator, audio output
12.1
THD
Total harmonic distortion
Dev.= 75kHz, V56=
100dBµV,IF2Q”11”
aAM
AM suppression
V56 =100dBµ, Δf=40KHz, fmod
=1KHz,
fmod =1KHz@AM, m=0.3%
40
60
Dev.= 75kHz
440
500
560
mVRMS
40
60
Ω
0.3
%
dB
12.2
VMPX
MPX output signal
12.3
ROUT
Output impedance
20
RLOAD
Load resistance
10
kΩ
70
dB
Δf=40KHz, fmod =1KHz, V56
12.4
(S+N)/N
=100dBµV,
Signal plus noise-to-noise
Deemphasis=50µs,
ratio at MPXOUT
B=200Hz to 15KHz
ISSENA = 0
13/76
Electrical specifications and characteristics
Table 6.
Item
12.5
TDA7541
FM section (continued)
(Tamb = 25°C, VCC1 = VCC2 = VCCMIX1 = VCCVCO = VCCIF = 8.5V, fXtal = 10.25 MHz,
fRF = 98MHz, dev = 40 kHz, fMod = 1 kHz, in application circuit, unless otherwise specified)
Symbol
(S+N)/N
Parameter
Test conditions
Δf=1.5KHz, fmod =1KHz, V56
Signal plus noise-to-noise
=100dBµ,
ratio
Deemphasis=75µs, setting see
In weatherband mode
Table 10
Min.
Typ.
Max.
40
Unit
dB
13. Quality detection
Unweighted field strength (FSU) and weighted field strength
13.1
V37
DC output voltage
V56 = 20 dBμV, FMON=1,
FSWO = OFF
2.5
V
13.2
V37
DC output voltage
V56 = 50 dBμV, FMON=1,
FSWO = OFF
3
V
13.3
V37
DC output voltage
V56 = 70 dBμV, FMON=1,
FSWO = OFF
3.5
V
13.4
V37
DC output voltage
V56 > 120 dBμV, FMON=1,
FSWO = OFF
4.6
V
13.5
ΔV37
Slope
25
mV/dB
13.6
ΔV37
DC offset
13.7
ROUT
Output impedance
FSWO
13.8
V27
DC output voltage
13.9
V27
13.10
0
mV
23.5
30
kΩ
V56 = 20 dBμV, FMON=1,
SL=”101”
0.1
0.4
V
DC output voltage
V56 = 50 dBμV, FMON=1,
SL=”101”
1
V
V27
DC output voltage
V56 = 70 dBμV, FMON=1,
SL=”101”
2
V
13.11
V27
DC output voltage
V56 > 120 dBμV, FMON=1,
SL=”101”
13.12
ΔV27
Slope
13.13
ROUT
Output impedance
FSU
13.14
Rload
Load resistor
FSU
20
13.15
V27
DC output voltage AM
V47 = 20 dBμV, FMON = 0,
SL= ”010”
0.1
13.16
V27
DC output voltage AM
V47 = 40 dBμV, FMON = 0,
SL= ”010”
1.25
V
13.17
V27
DC output voltage AM
V47 = 60 dBμV, FMON = 0,
SL= ”010”
3.0
V
13.18
V27
DC output voltage AM
V47 > 100 dBμV, FMON = 0,
SL= ”010”
13.19
ΔV27
Slope AM
FMON=0
14/76
-200
17
4
V
50
320
400
4.5
mV/dB
480
Ω
kΩ
0.3
V
V
90
mV/dB
TDA7541
Table 6.
Electrical specifications and characteristics
FM section (continued)
(Tamb = 25°C, VCC1 = VCC2 = VCCMIX1 = VCCVCO = VCCIF = 8.5V, fXtal = 10.25 MHz,
fRF = 98MHz, dev = 40 kHz, fMod = 1 kHz, in application circuit, unless otherwise specified)
Item
Symbol
13.20
fLP
Parameter
-3dB frequency low pass
AM
Test conditions
Min.
FMON=0
Typ.
Max.
Unit
40
kHz
32
dB
100
kHz
70
kHz
100
kHz
12
dB
19
kHz
Adjacent channel gain
13.21
GAC
Gain
Adjacent channel filter
-3dB frequency highpass
13.22
fHP
13.23
f-20dB
Attenuation 20dB
13.24
fBP
Centre frequency
ACF=0
ACF=1
Multipath channel gain
13.25
GMP
Gain
Multipath bandpass filter
13.26
fC
Centre frequency
13.27
Q
Quality factor
5
8
10
14. ISS (intelligent selectivity system) filter 450kHz
14.1
fcentre
Centre frequency
fREF_intern = 450kHz
14.2
BW 3dB
Bandwidth, -3dB
ISSBW = 1
70
80
90
kHz
14.3
BW 20dB Bandwidth, -20dB
ISSBW = 1
132
150
168
kHz
14.4
BW 3dB
ISSBW = 0
106
120
135
kHz
14.5
BW 20dB Bandwidth, -20dB
ISSBW = 0
220
250
280
kHz
14.6
BW 3dB
WBON = 1
18
22
26
kHz
14.7
BW 20dB -20dB weather band
Bandwidth, -3dB
Bandwidth weather band
450
kHz
WBON = 1
tbd
kHz
Adjacent channel ISS filter threshold
14.8
VTHAC
Internal low threshold
ACTH
2.75
V
14.9
VTHAC
Internal high threshold
ACTH
3.05
V
Multipath threshold
14.10
VTHMP
Internal low threshold
MPTH
0.50
V
14.11
VTHMP
Internal high threshold
MPTH
1.25
V
ISS filter time constant
14.12
I30,31
Charge current low mid
TISS, BWDEF = 1
-89
-74
-59
µA
14.13
I30,31
Charge current high mid
TISS, BWDEF = 1
-72
-60
-48
µA
14.14
I30,31
Charge current low narrow TISS, BWDEF = 1
-148
-124
-99
µA
14.15
I30,31
Charge current high
narrow
TISS, BWDEF = 1
-132
-110
-88
µA
14.16
I30,31
Discharge current low
TISS, BWDEF = 0
0.5
1
1.5
µA
15/76
Electrical specifications and characteristics
Table 6.
TDA7541
FM section (continued)
(Tamb = 25°C, VCC1 = VCC2 = VCCMIX1 = VCCVCO = VCCIF = 8.5V, fXtal = 10.25 MHz,
fRF = 98MHz, dev = 40 kHz, fMod = 1 kHz, in application circuit, unless otherwise specified)
Item
Symbol
Parameter
Test conditions
14.17
I30,31
Discharge current high
TISS, BWDEF = 0
14.18
V30,31
Low voltage
BWDEF = 0
14.19
V30,31
High voltage
BWDEF = 1
Min.
Typ.
Max.
Unit
11
15
19
µA
0.1
0.2
V
4.6
4.9
V
ISS filter switch threshold
14.20
V30,31
Threshold ISS on
BWDEF = 0
3
V
14.21
V30,31
Threshold ISS off
BWDEF = 0
1
V
14.22
V30,31
Threshold ISS narrow on
BWDEF = 0
4
V
14.23
V30,31
Threshold ISS narrow off
BWDEF = 0
2
V
Deviation detection
14.24
I3
Charge current low
TDEV
-40
-32
-20
µA
14.25
I3
Charge current high
TDEV
-48
-39
-30
µA
14.26
I3
Discharge current low
TDEV
0.5
1
1.5
µA
14.27
I3
Discharge current high
TDEV
5.5
8
10.5
µA
14.28
DEVWTH Internal low threshold
DWTH, I3 = 1µA
20
kHz
14.29
DEVWTH Internal high threshold
DWTH, I3 = 1µA
50
kHz
14.30 RATIOmin Referred to threshold
DTH
1
14.31 RATIOmax Referred to threshold
DTH
1.5
15. Weak signal mute
15.1
V37
Upper start point
WMTH=0, WMD=7, VIN=V56,
AF=-3dB
2.9
V
15.2
V37
Lower start point
WMTH=7, WMD=7, VIN=V56,
AF=-3dB
2.7
V
15.3
aWMD
Min. mute depth
WMD=0, WMTH=7, V56 =OFF
10
14
dB
15.4
aWMD
Max. mute depth
WMD=7, WMTH=7, V56=OFF
22
26
dB
15.5
aMTHISS
Mute threshold below
WMTH for ISS filter “ON”
WMD, WMTH, VIN=V56
1
dB
15.6
VACMTH
Internal AC mute
threshold
ACMTH
40
260
mV
15.7
aACMD
AC mute depth
ACMD
3
8
dB
15.8
I42
Charge current
-65
-47.5
-30
μA
15.9
I42
Discharge current
1.5
2.5
4
μA
0.1
0.2
V
16. Multiplexer output
16.1
V23
Output voltage low
16.2
V23
Output voltage high
16/76
4.6
4.9
V
TDA7541
Electrical specifications and characteristics
Table 6.
FM section (continued)
(Tamb = 25°C, VCC1 = VCC2 = VCCMIX1 = VCCVCO = VCCIF = 8.5V, fXtal = 10.25 MHz,
fRF = 98MHz, dev = 40 kHz, fMod = 1 kHz, in application circuit, unless otherwise specified)
Item
Symbol
16.3
ROUT
16.4
R23load
Table 7.
Item
Parameter
Test conditions
Min.
Typ.
Max.
Unit
Output resistance
200
250
300
Ω
Load resistor
20
kΩ
AM section
(Tamb = 25°C, VCC1 = VCC2 = VCCMIX1 = VCCVCO = VCCIF = 8.5V, fXtal = 10.25 MHz, fRF = 1
MHz, m = 30%, fmod = 1 kHz, in application circuit, unless otherwise specified)
Symbol
Parameter
Test conditions
Min.
Typ.
Max.
Unit
19
25
dBµV
17. Global
17.1
VANT_US
Usable sensitivity (1)
(S+N)/N = 26 dB
17.2
(S+N)/N
Signal to Noise Ratio
Ref.: V3 = 80dB∝V
50
55
dB
17.3
aIF
IF1 rejection
S/N=26dB, m=30%, fmod =1kHz
70
80
dB
17.4
V3
Min. RF AGC threshold
92
dBµV
17.5
V3
Max. RF AGC threshold
104
dBµV
17.6
V61
Min. IF AGC threshold
78
dBµV
17.7
V61
Max. IF AGC threshold
102
dBµV
17.8
V56
Min. DAGC threshold
86
dBµV
V56
Max. DAGC threshold
98
dBµV
3.5
V
17.9
RFAGC
IFAGC
DAGC
18. AGC voltage driver output
18.1
V4
Max. AGC output voltage
18.2
V4
Min. AGC output voltage
18.3
| I4 |
AGC current
3.3
0.5
V4=0V, V54 = 3.5V, LNA”00”
340
V
µA
19. AGC PIN diode driver output
19.1
I7
AGC driver current
-15
mA
20. AM Mixer1 (10.7MHz)
20.1
RIN
Input resistance
differential
20.2
CIN
Input capacitance
differential
20.3
ROUT
Output impedance
20.4
CP1dB
1dB compression point
20.5
V3,6
20.6
IIP3
20.7
INOISE
20.8
G
tbd
530
referred to diff. mixer input
Input DC bias
kΩ
45
660
pF
790
dBμV
112
0.3
rd
0.4
Ω
0.55
V
3 order intermodulation
132
dBμV
Equivalent input noise
5.5
nV/√Hz
Gain
With 330Ω filter
3
5.5
7
dB
17/76
Electrical specifications and characteristics
Table 7.
Item
TDA7541
AM section (continued)
(Tamb = 25°C, VCC1 = VCC2 = VCCMIX1 = VCCVCO = VCCIF = 8.5V, fXtal = 10.25 MHz, fRF = 1
MHz, m = 30%, fmod = 1 kHz, in application circuit, unless otherwise specified)
Symbol
Parameter
Test conditions
Min.
Typ.
Max.
Unit
265
330
396
Ω
21. AM mixer2
21.1
RIN
Input resistance
21.2
CIN
Input capacitance
21.3
V55.56
DC input voltage
3.8
21.4
ROUT
Output resistance
100
21.5
COUT
Output capacitance
21.6
V52,53
DC output voltage
21.7
gm
Conversion
transconductance
MIX2OUT
440
µA/V
21.8
Gmax
Max. gain
L=560µH, Q=28;
C=180p,referred to MIX2OUT
26
dB
21.9
ΔG
20
dB
21.10
Cstep
Min. cap. Step
IF2A
2.2
pF
21.11
Cmax
Max. cap.
IF2A
33
pF
21.12
INOISE
Equivalent input noise
voltage,
including buffer mixer2
Amax , Rgen=330Ω, RL=2kΩ,
noise of Rgen not included
11
nV/√Hz
21.13
CP1dB
1dB compression point
Amax , referred to 330Ω input
114
dBμV
Amax , referred to 330Ω input
132
dBμV
21.14
IIP3
2.5
3 order Intermodulation
4.2
3.7
V
kΩ
2.5
Gain control range
rd
4
pF
4.0
pF
4.3
V
22. Buffer AM mixer2
22.1
ROUT
Output resistance
22.2
COUT
Output capacitance
22.3
V50
22.4
G
1.6
2.4
2.5
DC output voltage
gain
2
RL=2kΩ
kΩ
pF
3.7
4.0
4.3
V
-8
-6
-4
dB
1.6
2
2.4
kΩ
23. AM IF2 amplifier
23.1
RIN
Input resistance
23.2
CIN
Input capacitance
23.3
V44,47
DC input voltage
4.1
4.3
4.5
V
23.4
Gmax
Max. gain
49
52
55
dB
23.5
ΔG
Gain control range
36
38
40
dB
23.6
INOISE
Equivalent input noise
voltage
Gmax , Rgen=2KΩ,
noise of Rgen not included
9.5
nV/√Hz
23.7
CP1dB
1dB compression point
Gmax , referred to 2KΩ input
74
dBμV
23.8
IIP3
3rd order Intermodulation
Gmax , referred to 2KΩ input
100
dBμV
18/76
2.5
pF
TDA7541
Electrical specifications and characteristics
Table 7.
AM section (continued)
(Tamb = 25°C, VCC1 = VCC2 = VCCMIX1 = VCCVCO = VCCIF = 8.5V, fXtal = 10.25 MHz, fRF = 1
MHz, m = 30%, fmod = 1 kHz, in application circuit, unless otherwise specified)
Item
Symbol
23.9
V23
Parameter
IF2 output voltage
Test conditions
V56 = 90dBµ, m=off
Min.
Typ.
Max.
Unit
140
190
240
mVRMS
24. AMAGC2
24.1
VAGC(start) AGC start voltage (PIN47)
Input carrier voltage
62
dBµV
55
dB
24.2
ΔAGC
AGC2 range
Between start of AGC2
and the intervention point
of prestage AGC
24.3
gAGC
Control slope
Seek mode
50
µA/V
24.4
gAGC
Control slope
normal mode
5
µA/V
24.5
II57I
Max. AGC charge current
Seek mode
125
μA
24.6
II57I
Max. AGC charge current
normal mode
5
μA
24.7
V57
Max. AGC output voltage
V47 = 100dBµ
4.8
V
24.8
V57
Min. AGC output voltage
V47 = 20dBµ
50
4.6
0.2
0.5
V
200
230
mVRMS
V56 = 90dBµ, m = 30%,
fmod = 1KHz
0.3
0.5
V56 = 90dBµ, m = 80%,
fmod = 1KHz
0.5
0.9
25
30
25. AM audio output
25.1
V43
Audio output voltage
25.2
THD
Total harmonic distortion
25.3
25.4
ROUT
V56 = 90dBµ, m = 30%,
fmod = 1KHz
Output impedance
170
%
20
Ω
26. IF noise blanking
26.1
tbl
Min. blanking time
8
μs
26.2
tbl
Max. blanking time
17
μs
26.3
Vth
Min internal threshold
50
mV
26.4
Vth
Max. internal threshold
187.5
mV
26.5
Vthstep
Threshold step
12.5
mV
1. Can be reached in application circuit, not measured.
19/76
Electrical specifications and characteristics
Table 8.
Item
TDA7541
Stereo decoder section
(Tamb=25°C, VCC1=VCC2=VCCMIX1=VCCVCO=VCCIF=8.5V, fXtal = 10.25 MHz,
VMPX=500mVrms mono, f=1kHz, deemphasis τ=50µs, in application circuit, unless otherwise
specified)
Symbol
Parameter
Test conditions
Min.
Typ.
Max.
Unit
0.5
0.93
Vrms
0.05
0.06
27. Stereo decoder
27.1
Vin
MPX input level
27.2
WBON = 1
Input resistance
80
100
120
kΩ
GSTD
Stereo decoder gain
2
2.5
3
dB
27.5
GSTDWB
Stereo decoder gain
Weather band mode
23
26
27
dB
27.6
SVRR
Supply voltage ripple
rejection
Vripple = 100mV, f = 1kHz
27.7
A
channel separation
VMPX = 500 mVrms stereo, only
L/R, ROC adjusted
27.8
THD
Total harmonic distortion
27.9
(S+N)/N
Signal plus noise to noise
ratio
27.3
Rin
27.4
35
60
dB
40
dB
0.02
A-weighted, 19 kHz notch
0.3
85
%
dB
28. Mono/stereo switch
28.1
VPTHST1
Pilot threshold voltage
for Stereo, PTH = 1
5
8
12
mVrms
28.2
VPTHST0
Pilot threshold voltage
for Stereo, PTH = 0
7
11
16
mVrms
28.3
VPTHMO1 Pilot threshold voltage
for Mono, PTH = 1
3.5
6
10
mVrms
28.4
VPTHMO0 Pilot threshold voltage
for Mono, PTH = 0
6
9
14
mVrms
18.9
19.1
kHz
30
%
29. 19kHz PLL
29.1
flock
Capture range
Pilot magnitude 20 mVrms = 4%
29.2
DP
Pilot deviation range
fpilot = 19kHz
4
30. Deemphasis and highcut
30.1
tHC50
Deemphasis time
constant
DEEMP=0, High Cut OFF
45
50
55
μs
30.2
tHC75
Deemphasis time
constant
DEEMP = 1, High Cut OFF
67
75
83
μs
30.3
tHC50
Highcut time constant
DEEMP = 0, High Cut ON,
V28=0.1V
135
150
165
μs
30.4
tHC75
Highcut time constant
DEEMP= 1, High Cut ON,
V28=0.1V
200
225
250
μs
30.5
AAmmin
Min. Attenuation in AM
Voutmax/Vout@ f = 3.5kHz,
DEEMP = 0, AMCF “111”
4.5
6.5
8.5
dB
30.6
AAmmax
Max. Attenuation in AM
Voutmax/Vout@ f = 3.5kHz,
DEEMP= 0, AMCF “000”
11
14
17
dB
20/76
TDA7541
Electrical specifications and characteristics
Table 8.
Item
Stereo decoder section (continued)
(Tamb=25°C, VCC1=VCC2=VCCMIX1=VCCVCO=VCCIF=8.5V, fXtal = 10.25 MHz,
VMPX=500mVrms mono, f=1kHz, deemphasis τ=50µs, in application circuit, unless otherwise
specified)
Symbol
Parameter
Test conditions
Min.
Typ.
Max.
Unit
31. Stereo blend and high cut control
31.1
LGmin
Min. level gain
LG
-0.3
0
0.3
dB
31.2
LGmax
Max. level gain
LG
7.75
8.25
8.75
dB
31.3
LGstep
Level gain step Resolution
0.25
0.55
0.85
dB
31.4
VSBLmin Min. voltage for mono
SBC
24
29
34
%VREF1
31.5
VSBLmax Max. voltage for mono
SBC
53
58
63
%VREF1
31.6
VSBLstep Step resolution
SBC
3.5
4.2
5
%VREF1
31.7
VHCHmin Min. voltage for no highcut HCHT
37
42
47
%VREF1
31.8
VHCHmax Max.voltage for no highcut HCHT
61
66
71
%VREF1
31.9
VHCHstep Step resolution
HCHT
7
8
9
%VREF1
31.10 VHCLmin
Min. voltage for full high
cut
HCLT
6
11
16
%VHCH
31.11 VHCLmax
Max. voltage for full high
cut
HCLT
28
33
38
%VHCH
HCLT
6.5
7.3
8.1
%VHCH
45
50
dB
31.12 VHCLstep Step resolution
32. Carrier and harmonic suppression at the output
32.1
a19
Pilot signal f=19kHz
32.2
a38
Subcarrier f=38kHz
75
dB
32.3
a57
Subcarrier f=57kHz
62
dB
32.4
a76
Subcarrier f=76kHz
90
dB
33. Intermodulation
(1)
33.1
a2
fmod=10kHz, fspur=1kHz
65
dB
33.2
a3
fmod=13kHz, fspur=1kHz
75
dB
70
dB
75
dB
34. Traffic radio (2)
34.1
a57
Signal f=57kHz
65
35. SCA (3)
35.1
a67
Signal f=67kHz
36. ACI – adjacent channel interference (4)
36.1
a114
Signal f=114kHz
95
dB
36.2
a190
Signal f=190kHz
84
dB
147
mVOP
37. FM noise blanker
37.1
VTRMIN
Min. trigger threshold (5)
VPEAK=0.8V, NBLT “111”
21/76
Electrical specifications and characteristics
Table 8.
TDA7541
Stereo decoder section (continued)
(Tamb=25°C, VCC1=VCC2=VCCMIX1=VCCVCO=VCCIF=8.5V, fXtal = 10.25 MHz,
VMPX=500mVrms mono, f=1kHz, deemphasis τ=50µs, in application circuit, unless otherwise
specified)
Item
Symbol
37.2
VTRMAX
37.3
Parameter
Test conditions
Min.
Typ.
Max.
Unit
Max. trigger threshold (5)
VPEAK=0.8V, NBLT “000”
280
mVOP
VTRNOISE
Min. noise controlled
trigger threshold
VPEAK=1.5V, NBCT “11”
450
mVOP
37.4
VTRNOISE
Max. noise controlled
trigger threshold
VPEAK=1.5V, NBCT “00”
1200
mVOP
37.5
VPEAK
Peak voltage
NBRR “00”, VMPX=0mV
0.8
V
37.6
VPEAK
Peak voltage
NBRR “00”, VMPX=50mV,
f=150kHz
1.9
V
37.7
VPEAK
Peak voltage
NBRR “00”, VMPX=200mV,
f=150kHz
3.5
V
37.8
VPEAKDEV
Min. deviation dependent
peak voltage
VMPX=500mV, NBDC = 11 (“OFF”)
0.8
V
37.9
VPEAKDEV
Max. deviation dependent
VMPX=500mV, NBDC= 00
peak voltage
2.0
V
37.10
Min. fieldstrength
VPEAKFS controlled
peak voltage
VMPX=0mV, VLEVEL<< VSBL
(fully mono), NBFC = 11 (“OFF”)
0.8
V
37.11
Max. fieldstrength
VPEAKFS controlled
peak voltage
VMPX=0mV, VLEVEL<< VSBL
(fully mono), NBFC = 00
2.0
V
37.12
TS
Min. blanking time
Signal HOLDN in testmode,
NBT = 00
38
μs
37.13
TS
Max. blanking time
Signal HOLDN in testmode,
NBT = 11
22
μs
37.14
SRPEAK
Noise rectifier charge
Signal PEAK in testmode,
NBPC=0
5
mV/μs
37.15
SRPEAK
Noise rectifier charge
Signal PEAK in testmode,
NBPC=1
12
mV/μs
37.16 VRECTADJ
Noise rectifier discharge
adjustment
Signal PEAK in testmode,
NBRR=00
0.3
V/ms
37.17 VRECTADJ
Noise rectifier discharge
adjustment
Signal PEAK in testmode,
NBRR=01
1.8
V/ms
37.18 VRECTADJ
Noise rectifier discharge
adjustment
Signal PEAK in testmode,
NBRR=10
2.8
V/ms
37.19 VRECTADJ
Noise rectifier discharge
adjustment
Signal PEAK in testmode,
NBRR=11
4
V/ms
37.20
Noise rectifier adjustment
by multipath
Signal PEAK in testmode,
VMPTC=1V, NBSMP=0, NBMP=1,
NBRR=01
3
V/ms
22/76
VADJMP
TDA7541
Electrical specifications and characteristics
Table 8.
Stereo decoder section (continued)
(Tamb=25°C, VCC1=VCC2=VCCMIX1=VCCVCO=VCCIF=8.5V, fXtal = 10.25 MHz,
VMPX=500mVrms mono, f=1kHz, deemphasis τ=50µs, in application circuit, unless otherwise
specified)
Item
Symbol
Parameter
Test conditions
Min.
Typ.
37.21
VADJMP
Noise rectifier adjustment
by strong multipath
influence
Signal PEAK in testmode,
VMPTC=1V, NBSMP=1,
NBMP=0, NBRR=01
4
37.22
VADJMP
Noise rectifier adjustment
by multipath and strong
multipath influence
Signal PEAK in testmode,
VMPTC=1V, MBSMP=1,
NBMP=1, NBRR=01
5.2
Max.
Unit
V/ms
38. Multipath detector
38.1
GMP
Min. multipath gain
MPG = 00
5
6
7
dB
38.2
GMP
Max. multipath gain
MPG = 11
11
12
13
dB
38.3
GRECTMP Min. rectifier gain
MPRG = 01
-1
0
1
dB
38.4
GRECTMP Max. rectifier gain
MPRG = 11
5
7.6
9
dB
38.5
ICHMP
Rectifier charge current
MPCC = 0
0.5
0.8
1.1
μA
38.6
ICHMP
Rectifier charge current
MPCC = 1
0.2
0.4
0.7
μA
38.7
IDISMP
Rectifier discharge current
0.5
1
mA
39. Quality detector
39.1
a
Min. quality detector
coefficient
QDC
0.5
0.6
0.7
39.2
a
Max. quality detector
coefficient
QDC
0.9
1.05
1.2
39.3
b
Min. quality noise gain
QNG
5
6
7
dB
39.4
b
Max. quality noise gain
QNG
13
15
17
dB
1. Intermodulation suppression
V o ( signal ,@1kHz )
a2 = ------------------------------------------------------------- ;ƒs = ( ( 2 × 10kHz ) – 19kHz )
V o ( spurious ,@1kHz )
V o ( signal ,@1kHz )
a3 = ------------------------------------------------------------- ;ƒs = ( ( 3 × 13kHz ) – 38kHz )
V o ( spurious ,@1kHz )
measured with: 91% stereo signal; 9% pilot signal; fm = 10kHz or 13kHz.
2. Traffic radio (V.F.) suppression
V o ( signal ,@1kHz )
a57 ( V ,W ,F ) = ------------------------------------------------------------------------------------V o ( spurious ,@1kHz ) ± 23kHz
measured with: 91% stereo signal; 9% pilot signal; fm=1kHz; 5% sub carrier (f=57kHz, fm=23Hz AM, m=60%)
23/76
Electrical specifications and characteristics
TDA7541
3. SCA (subsidiary communications authorization)
V o ( signal ,@1kHz )
a67 = ------------------------------------------------------------- ;ƒs = ( ( 2 × 38kHz ) – 67kHz )
V o ( spurious ,@9kHz )
measured with: 81% mono signal; 9% pilot signal; fm=1kHz; 10%SCA - sub carrier (fS = 67kHz, unmodulated)
4. ACI (adjacent channel interference)
V o ( signal ,@1kHz )
a114 = ------------------------------------------------------------- ;ƒs = ( 110kHz – ( 2 × 38kHz ) )
V o ( spurious ,@4kHz )
V o ( signal ,@1kHz )
a190 = ------------------------------------------------------------- ;ƒs = ( 186kHz – ( 5 × 38kHz ) )
V o ( spurious ,@4kHz )
measured with: 90% mono signal; 9% pilot signal; fm=1kHz; 1% spurious signal (fS = 110kHz or 186kHz, unmodulated)
5. All thresholds are measured in test mode at the quality output. The thresholds are calculated by VNBTH - VPEAK. VPEAK can
be adjusted by applying a 150 kHz sinewave at MPXIN.
Table 9.
PLL section
(Tamb=25°C, VCC1=VCC2=VCCMIX1=VCCVCO=VCCIF=8.5V, fXtal = 10.25 MHz,
VMPX=500mVrms mono, f=1kHz, de-emphasis τ=50µs, in application circuit, unless
otherwise specified)
Item Symbol
Parameter
Test conditions
Min.
Typ.
Max.
Unit
40. Voltage controlled oscillator (VCO)
40.1
fVCOmin
40.2
fVCOmax Max. VCO frequency
40.3
C/N
Min. VCO frequency
Carrier-to-noise-ratio
160
MHz
260
fVCO= 200MHz, Δf=1KHz,
B=1Hz, Qloaded=60
MHz
80
dBc/√Hz
10.25
MHz
41. Crystal oscillator
41.1
fxtal
Crystal frequency
41.2
C/N
Carrier-to-noise-ratio
41.3
V29
Oscillator output voltage
400
mVrms
41.4
C29-32
Input capacitance
2.5
pF
41.5
Cstep
Min. cap. Step
XTAL
0.75
pF
41.6
Cmax
Max. cap.
XTAL
23.25
pF
41.7
Δf/f
Deviation versus VCC
Δ VCC=1V
1.5
ppm/V
41.8
Δf/f
Deviation versus T
-40°C<T<+85°C
0.2
ppm/K
50
μA
50
μA
550
μA
500
μA
fxtal =10.25MHz, Δf=10KHz
dBc/√Hz
110
42. Charge pump current
42.1
-I20
Source current
42.2
I20
Sink current
42.3
-I20
Source current
I20
Sink current
42.4
24/76
V20 = 2.5V
ICP, V20 = 2.5V
TDA7541
Table 9.
Electrical specifications and characteristics
PLL section (continued)
(Tamb=25°C, VCC1=VCC2=VCCMIX1=VCCVCO=VCCIF=8.5V, fXtal = 10.25 MHz,
VMPX=500mVrms mono, f=1kHz, de-emphasis τ=50µs, in application circuit, unless
otherwise specified)
Item Symbol
Parameter
42.5
-I20
Source current
42.6
I20
Sink current
42.7
-I20
Source current
42.8
I20
Sink current
Test conditions
Min.
ICP, V20 = 2.5V
Typ.
Max.
Unit
1
mA
1
mA
1.9
mA
1.9
mA
43. Loop filter input/output
43.1
-IIN
Input leakage current
VIN = GND: PDOUT = Tristate
-0.1
0.1
μA
43.2
IIN
Input leakage current
VIN = VREF1 PDOUT = Tristate
-0.1
0.1
μA
43.3
VOL
Output voltage Low
IOUT = -0.2mA
0.5
V
43.4
VOH
Output voltage High
IOUT = 0.2mA
43.5
IOUT
Output current, sink
VOUT = 1V to VCCVCO-1V
43.6
IOUT
Output current, source
VOUT = 1V to VCCVCO-1V
0.05
VCCVCO- VCCVCO0.5
0.05
V
10
-10
mA
mA
44. Output of tuning voltage (TV)
VVCO0.5
44.1
VOUT
Output voltage
44.2
IVstepI
Min. voltage step
TVO
25
mV
44.3
IVmaxI
Max. voltage offset
TVO
3175
mV
44.4
ΔV
Additional offset voltage
TVM=1, TVO+
3.175
V
44.5
ROUT
Output impedance
TVM=0
40
kΩ
44.6
ROUT
Output impedance
TVM=1
20
kΩ
I24 = -200μA
0.2
0.5
V
45. SSTOP output (open collector)
45.1
V24
Output voltage low
45.2
V24
Output voltage high
45.3
-I24
Output leakage current
V 24 = 5V
45.4
I24
Output current, sink
V 24 = 0.5V to 5V
-0.1
0.5
V
5
V
0.1
μA
1
mA
45.5
Internal unfiltered field
V37SSTH strength threshold for
SSTOP=HIGH
SSTH, FMON=1
2.6
4.1
V
45.6
Internal unfiltered field
V27SSTH strength threshold for
SSTOP=HIGH
SSTH, FMON=0
SL = “011”
1.2
4.8
V
0.5
V
46. Switch output
46.1
VOL
Output Voltage low
SWM”1”,SW”0”, I24 = -5μA
46.2
VOH
Output Voltage high
SWM”1”,SW”1”
0.35
VCC-1
V
25/76
Electrical specifications and characteristics
Table 9.
TDA7541
PLL section (continued)
(Tamb=25°C, VCC1=VCC2=VCCMIX1=VCCVCO=VCCIF=8.5V, fXtal = 10.25 MHz,
VMPX=500mVrms mono, f=1kHz, de-emphasis τ=50µs, in application circuit, unless
otherwise specified)
Item Symbol
Parameter
Test conditions
Typ.
46.3
-I22
Output leakage current
46.4
I22
Output Current, sink
46.5
VOL
Output Voltage low
SWM”0”,SW”0”, I22=0µA
0.1
46.6
VOH
Output Voltage high
SWM”0”,SW”1”, I22=1mA
VCC-1
46.7
I22
Output Current, sink
V22=5V
26/76
V22=5V
Min.
-0.5
-7
Max.
Unit
0.5
μA
7
mA
0.3
V
V
mA
TDA7541
Functional description
4
Functional description
4.1
FM part
4.1.1
Mixer 1 AGC and IF amplifier
FM quadrate I/Q-mixer converts FM RF to IF1 of 10.7MHz. The mixer provides inherent
image rejection and wide dynamic range with low noise and large input signal performance.
For accurate image rejection the phase-error of I/Q can be compensated by software (PH).
It is capable of tuning the US FM, US weather (dedicated WB input), Europe FM, Japan FM
and East Europe FM bands
–
US FM = 87.9 to 107.9 MHz
–
US weather = 162.4 to 162.55 MHz
–
Europe FM = 87.5 to 108 MHz
–
Japan FM = 76 to 91 MHz
–
East Europe FM = 65.8 to 74 MHz
The AGC operates on different sensitivities and bandwidths in order to improve the input
sensitivity and dynamic range. AGC thresholds are programmable by software (RFAGC,
IFAGC, and KAGC). The output signal is a controlled current for pin diode attenuator.
A 10.7MHz programmable amplifier (IFG) correct the IF ceramic insertion loss and the
costumer level plan application.
4.1.2
Mixer2, limiter, FM demodulator and spike cancellation
In the 2nd mixer stage the first 10.7MHz IF is converted into the second 450 kHz IF.
The fully integrated sample and hold FM demodulator including spike cancellation (DSB)
converts the IF signal from the 450KHz limiter (limiter gain 80dB typ.) to the FM multiplex
output signal with very low distortion.
The sensitivity of spike blanking can be set via I2C-bus.
4.1.3
Quality detection and ISS
Field strength
Parallel to mixer2 input a 10.7MHz limiter generates a signal for digital IF counter and field
strength voltage VFSUint. This internal voltage VFSUint is used for AM IF noise blanker,
adjacent channel and multi path detection and is available at PIN27 (FSU) in a range of 0V
to 5V. The offset and slope of FSU signal can be adjusted via IIC-bus (FSWO and SL) for
application adaptation.
The voltage VFSWO including offset adjust is externally filtered at PIN37 (FSWO) and used
for weak signal mute function and generation of ISS filter control signals in weak signal
condition. It is possible to combine the IF counter result with this voltage VFSWO by
programmable comparator threshold (SSTH).
27/76
Functional description
TDA7541
Adjacent channel detector
The input of the adjacent channel detector is AC coupled from VFSW. A programmable
high-pass or band-pass (ACF) as well as rectifier generate a signal which is compared with
adjustable threshold (ACTH). The output signals of this comparator is controlling the charge
and discharge of the external capacitor at PIN30 or PIN31 (dependent on SEEK) with
programmable discharge current (TISS). The level at PIN30/31 is used to generate the two
digital signal ac and ac+ for ISS control. The adjacent channel information behind the
rectifier is available as analog output signal at the multiplexer output (PIN23).
Multipath detector
The input of the multi path detector is AC coupled from internal VFSW too. After filtering with
19 kHz band-pass and rectifying, this voltage is compared with an adjustable threshold
(MPTH). The output signal of this comparator can be used to switch off the adjacent channel
detection. This influence is selectable by I2C Bus (MPENA).
The multi path information behind the rectifier is available as analog output signal at
multiplexer output (PIN23).
450 kHz IF narrow band pass filter (ISS filter)
The device has an additional 450 kHz IF narrow band-pass filter for suppression of noise
and adjacent channel signal influences. This narrow filter has three switchable bandwidths,
narrow range of 80 kHz, mid range of 120 kHz and 24 kHz for weather band information.
Without ISS (Intelligent Selectivity System) filter the IF bandwidth (wide range) is defined
only by ceramic filter chain and mixer2 bandwidth. The filter is located between mixer2
output buffer and 450 kHz limiter stage. The centre frequency is matched to the
demodulator centre frequency.
Deviation detector
In order to avoid distortion in audio output signal the narrow ISS filter is switched OFF if over
deviation is present. Hence the demodulator output signal is detected. After AC coupling,
low-pass filtering and peak rectifying this signal is charging/discharging the external DEVTC
capacitor by an IIC programmable charge/discharge current (TDEV). The voltage at DEVTC
is compared with adjustable thresholds (DWTH, DTH) and generates two digital control
signals (dev, dev+). For weak signal condition the deviation threshold depends on FSWO.
ISS switch logic
All digital control signals coming from adjacent channel detector, deviation detector and
weak signal mute are acting via switching matrix on ISS filter switch. IF2 narrow band-pass
switch mode is controlled also by software (ISSENA, ISSON, WBON, ISSBW, and BWDEF).
The switching of the IF band-pass is also possible to influence by external manipulation of
DC voltage at PIN30.
The influence of the ISS software control on the functionality of the ISS filter is described in
Table 10. The value “X” for the control bit means the bit does not influence the filter control in
this condition.
28/76
TDA7541
Functional description
ISS filter control by I2C bus
Table 10.
ISSENA adr4/d2
ISSON adr11/d0
ISSBW adr7/d0
WBON adr11/d1
ISSM adr9/d7
BWDEF adr7/d1
I2C control bits
0
X
X
X
X
X
ISS filter is switched off (bypass)
1
1
0
X
X
X
ISS filter is in manual control mode, Band width is 120 kHz
1
1
1
X
X
X
ISS filter is in manual control mode, Band width is 80 kHz
1
1
X
1
X
X
ISS filter is in manual control mode, Band width is 24 kHz
This setting must be used for weather band application
1
0
X
X
0
0
ISS filter is in automatic control mode
Filter activation and band width defined by control table mode1
1
0
X
X
1
0
ISS filter is in automatic control mode
Filter activation and band width defined by control table mode2
1
0
0
X
0
1
ISS filter is in automatic control mode
Filter activation defined by control table mode1
band width fixed to 120 kHz
1
0
0
X
1
1
ISS filter is in automatic control mode
Filter activation defined by control table mode2
band width fixed to 120 kHz
1
0
1
X
0
1
ISS filter is in automatic control mode
Filter activation defined by control table mode1
band width fixed to 80 kHz
1
0
1
X
1
1
ISS filter is in automatic control mode
Filter activation defined by control table mode2
band width fixed to 80 kHz
Notes
Description of I2C bits:
ISSENA
ISS filter enable
“1”: ISS filter control enabled
“0”: ISS filter is switched off (bypass of the filter, wide)
ISSON
ISS filter control mode
“1”: ISS filter is in manual control mode (switched "ON"); the bits ISSBW and WBON are
defining the bandwidth
“0”: ISS filter is in automatic control mode according to mode1/2 table
ISSBW
ISS filter band width
“1”: 80 kHz
29/76
Functional description
TDA7541
“0”: 120 kHz
The bit has only influence if bit BWENA is “1”, or if bit ISSON is “1”
WBON
Weather band enable
“1”: Weather band enable (FMmixer1 is disabled, Wbmixer1enabled, stereo decoder gain
26dB, ISS filter bandwidth 24 kHz,IF2Q=”00”)
“0”: Weather band disable
For weather band enable it is need to set ISSON = “1”
ISSM
ISS filter application mode
“0”: ISS filter application mode1
“1”: ISS filter application mode2
If BWENA is “1” the band width is always switched to ISSBW in case of ISS filter activated
BWDEF
Enable bit ISSBW for ISS filter band with control
“1”: ISS filter is internally controlled, but band width is defined by bit ISSBW
“0”: ISS filter is internally controlled, band width is defined by mode1/2 table
For the internal control two application modes are available (ISSM). The conditions and
settings are described in Table 10 and Table 11.
4.1.4
Block diagram quality detection principle
(without overdeviation correction)
Table 11.
Signal
30/76
Internal ISS control signals
Low
High
Ac
No adjacent channel
Adjacent channel present
ac+
No strong adjacent channel
Adjacent channel higher as ac
Sm
Field strength higher as weak signal mute
threshold
Field strength lower as weak signal mute
threshold
Dev
Deviation lower as threshold DWTH
Deviation higher as threshold DWTH
dev+
Deviation lower as threshold DTH*DWTH
Deviation higher as threshold DTH*DWTH
Inton
ISS filter off by logic (wide)
ISS filter on by logic
int80
ISS filter 120kHz (mid)
ISS filter 80kHz (narrow)
TDA7541
Functional description
Table 12.
ISS control modes
Input signals
4.1.5
Mode1
Mode2
ac
ac+
sm
dev
dev+
inton
int80
Function
inton
int80
Function
0
0
0
0
0
0
0
wide
0
0
wide
0
0
0
1
0
0
0
wide
0
0
wide
0
0
0
1
1
0
0
wide
0
0
wide
0
0
1
0
0
1
1
narrow
1
1
narrow
0
0
1
1
0
0
0
wide
1
0
mid
0
0
1
1
1
0
0
wide
0
0
wide
1
0
0
0
0
1
1
narrow
1
0
Mid
1
1
0
0
0
1
1
narrow
1
1
Narrow
1
0
0
1
0
1
0
mid
1
0
Mid
1
1
0
1
1
1
0
mid
1
1
Narrow
Weak signal mute
The filtered field strength signal (FSWO) is the reference for soft slope mute control in weak
signal condition to eliminate audible effects. The start point and mute depth are
programmable (WMTH, WMD) in a wide range. These settings together with FSWO bits are
influencing the weak signal mute behaviour. The time constant is defined by external
capacitance at PIN 42. Additional adjacent channel mute function is supported. A high pass
filter with -3dB threshold frequency of 100 kHz, amplifier and peak rectifier generates an
adjacent noise signal from Demodulator output. This value is compared with adjustable
threshold (ACMTH). For present strong adjacent channel the MPX signal is additional
attenuated (ACMD) and has the same time constant as weak signal mute.
4.1.6
Weather band input
If the weather band input is used the chip must be set in FM mode (FMON). In addition to
that the ISS filter must be switched ON (ISSENA), mixer2 quality must set to IF2Q=”00” and
the ISS filter must be set in manual control mode. The bit WBON is activating the WB input
and is switching the ISS filter in WB mode (24 kHz band width).
4.2
AM section
The up/down conversion in AM signal path is combined with gain control circuit sensing
three input signals, narrow band information (DAGC) referred to PIN 56, up conversion
signal (IFAGC) at PIN 61 and wide band information (RFAGC) at PIN 3.This gain control
gives two output signals. The first one is a current for pin diode attenuator and the second
one is a voltage for preamplifier. Time constant of RF- and IF-AGC is defined by internal
100k resistor and external capacitor at PIN 54. The intervention points for AGC (DAGC,
IFAGC and RFAGC) are programmable by software. The oscillator frequency for
upconversion mixer1 is generated by dividing the VCO frequency after VCO divider (VCOD)
and AM predivider (AMD).
Two 10,7MHz ceramic filters before mixer2 input increase 900KHz attenuation.
31/76
Functional description
TDA7541
The AMIF2 block contains mixer2, IF2 amplifier, demodulator and AGC2
The AM/FM mixer2 converts 10.7MHz IF1 into 450 kHz IF2. Mixer2 output passes a 450
kHz narrow band filter (LC plus ceramic filter). LC centre frequency is adjustable by IIC-bus
(IF2A). The following IF2 amplifier provides signal for fully integrated demodulator.
Mixer2 and IF2 amplifier have a 2-stage AGC with careful take-over behaviour to keep
distortion low. The IF2 AGC range is about 55dB.
The input signal of IF2 amplifier is used in limiter circuit for in-band level detection. The
electrical characteristics are described in FM section.
The demodulator is a peak detector to generate the audio output signal.
At the MUX output the AMIF stereo is available.
AM IF noise blanker
In order to remove in AM short spikes a noise cancellation conception is used in 450KHz IF
AM level. The advantage is to avoid long narrow AGC- and demodulator- time constants,
which enlarge spike influences on audio signal and makes difficult to remove it in audio path.
The 10,7MHz AM IF signal behind IF1 amplifier generates via limitation an unweighted field
strength signal including slope of noise spike. The comparison of this detected slope
between fast and slow rectifier ignores audio modulation whereby the threshold of slow
rectifier is programmable (AINBT). A comparator activates a pulse generator. The duration
of this pulse is software programmable (AINT) and is smooth blanking out the spikes in
mixer2.
4.3
Stereo decoder
4.3.1
Decoder
The stereo decoder-part of the TDA7541 contains all functions necessary to demodulate the
MPX-signal, like pilot tone-dependent MONO/STEREO switching as well as the stereo
blend and high cut.
Adaptations like programmable input gain, roll-off compensation, selectable deemphasis
time constant and a programmable field strength input allow easy adoption to different
applications.
The 4.th order input filter has a corner frequency of 80 kHz and is used to attenuate spikes
and noise and acts as an anti-aliasing filter for the following switch capacitor filters.
Demodulator
In the demodulator block the left and the right channel are separated from the MPX-signal.
In this stage also the 19-kHz pilot tone is canceled. For reaching a high channel separation
the TDA7541 offers an I2C bus programmable roll-off adjustment, which is able to
compensate the low pass behavior of the tuner section. Within the compensation range an
adjustment to obtain about 40dB channel separation is possible. The bits for this adjustment
are located together with the level gain adjustment in one byte. This gives the possibility to
perform an optimization step during the production of the car radio where the channel
separation and the field strength control are trimmed.
In addition to that the FM signal can be inverted.
32/76
TDA7541
Functional description
Deemphasis and high cut
The deemphasis low pass allows to choose between a time constant of 50µs/75µs
(DEEMP). The high cut control range will be in both cases THC = 2 x TDeemp. Inside the high
cut control range (between VHCHT and VHCLT) the LEVEL signal is converted into a 5-bit
word, which controls the low pass time constant between TDeemp...3 x TDeemp. Thereby the
resolution will remain 5 bits referred to the voltage range between the VHCHT- and minimum
VHCLT-values.
The high cut function can be switched off by I2C-bus.
Figure 3.
Programming of HC filter
High Cut Filter
Time Constant
00
3*TDeemp
11
HCMax
01
TDeemp
VFSTC* LG
VHCLT
VHCHT
In AM mode (FMON = 0) the DEEMP bit together with the AM corner frequency bits (AMCF)
can be used as programmable AM frequency response. The maximum corner frequency is
defined by TDeemp, the minimum is defined by 3 x TDeemp For the over all frequency
response it is need to take into account the frequency response of the AF output at
MPXOUT and the Stereo decoder demodulator too.
19 kHz PLL and pilot tone detector
The PLL has the task to lock on the 19 kHz pilot tone during a stereo-transmission to allow a
correct demodulation. The included pilot tone-detector enables the demodulation if the pilot
tone reaches the selected pilot tone threshold VPTHST. Two different thresholds are
available. The status of the detector output can be checked by reading the status byte of the
TDA7541 via I2C bus or by reading the STEREO status at MUX pin23.
Field strength control
The field strength input is used to control the high cut- and the stereo blend-function. In
addition the signal can be also used to control the noise blanker thresholds and as input for
the multipath detector.
LEVEL input and gain
As level input for the stereo decoder is used the FSU voltage (pin27). Applying a capacitor at
FSTC (pin28) a desired time constant can by reached together with the internal resistor of
10k between FSU pin and FSTC pin. The second stage is a programmable gain stage to
adapt the VFSTC signal internally. The gain (LG) is widely programmable in 16 steps from
0dB to 8.25dB (step=0.55dB). These 4 bits are located together with the Roll-Off
33/76
Functional description
TDA7541
compensation bits in byte14 to simplify a possible adaptation during the production of the
car radio.
Stereo blend control
The stereo blend control block converts the internal LEVEL-voltage into a demodulator
compatible analog signal, which is used to control the channel separation between 0dB and
the maximum separation. Internally this control range has a fixed upper limit, which is the
internal reference voltage VREF1. The lower limit can be programmed between 29 and 58%
of VREF1 in 4% steps. In order to adjust the external voltage VFSTC to the internal control
range two values must be defined: the Level gain LG and VSBL. Full channel separation is
reached when the internal level voltage (VST) becomes bigger than VREF1. Therefore the
following equation can be used to estimate the gain:
V REF1
LG = ---------------------------------------------------V FSTC @ fullstereo
The MONO-voltage VMO (0dB channel separation) can be chosen selecting SBC.
Figure 4.
Programming of stereo blend
Highcut control
The high cut control set-up is similar to the stereo blend control set-up: the starting point
VHCH can be set with 2 bits to be 42, 50, 58 or 66% of VREF1 whereas the range can be
set to be 11, 18.3, 25.7 or 33% of VHCH.
4.3.2
Noise blanker
In the automotive environment spikes produced for example by the ignition or the wipermotor disturb the MPX-signal. The aim of the noise blanker part is to cancel the audible
influence of the spikes. Therefore the output of the stereo decoder is held at the actual
voltage for a time between 22ms and 38ms (programmable).
In a first stage the spikes must be detected but to avoid a wrong triggering on high
frequency (white) noise a complex trigger control is implemented. Behind the trigger stage a
pulse former generates the "blanking"-pulse. An own biasing circuit supplies the noise
blanker in order to avoid any cross talk to the signal path.
Trigger path
The incoming FM demodulator output signal is taken in front of the weak signal mute, high
pass filtered, amplified and rectified. This second order high pass filter has a corner-
34/76
TDA7541
Functional description
frequency of 140 kHz. The rectified signal, VRECT, is low pass filtered to generate a signal
called VPEAK. Noise with a frequency above 140 kHz increases the VPEAK voltage. The
resulting voltage can be adjusted by use of the noise rectifier discharge current. The VPEAK
voltage is fed to a threshold generator, which adds to the VPEAK voltage a DC threshold
VTH. Both signals, VRECT and VPEAK+VTH are fed to a comparator, which triggers a retriggerable monoflop. The output of the monoflop activates the sample-and-hold circuit in
the signal path for the selected duration.
Automatic noise controlled threshold adjustment
There are mainly two independent possibilities for programming the trigger threshold:
1.
Low threshold in 8 steps (NBLT)
2.
Noise adjusted threshold in 4 steps (NBCT).
The low threshold is active in combination with a good MPX signal without any noise; the
VPEAK voltage is less than 1V. The sensitivity in this operation is high.
If the MPX signal is noisy (low field strength) the VPEAK voltage increases due to the higher
noise, which is also rectified. With increasing of the VPEAK voltage the trigger threshold
increases, too. This particular gain is programmable in 4 steps (NBCT).
Figure 5.
Adaptive threshold control of noise blanker
VTH
1200 mV (00)
950 mV (01)
700 mV (10)
450 mV (11)
Noise Controlled Trig. Threshold
Min. Trig. Threshold
200 mV
8 STEPS
147 mV
0.8 V
1.5 V
V
Peak
Automatic stereo blend controlled threshold adjustment
Besides the noise controlled threshold adjustment there is an additional possibility for
influencing the noise blanker trigger threshold using the bits NBFC. This influence depends
on the stereo blend control. The point where the MPX signal starts to become noisy is fixed
by the RF part. This point is also the starting point of the normal noise-controlled trigger
adjustment. But in some cases the noise blanker can create a wrong triggering, which
create distortion, already in the region of mono/stereo transition. Therefore an opportunity to
control the VPEAK voltage by the stereo blend function it is implemented.
35/76
Functional description
Figure 6.
TDA7541
Stereo blend controlled threshold adjust
VPEAK
MONO
STEREO
≈ 3V
2.0V (00)
1.6V (01)
1.4V (10)
NOISE
0.8V
ATC_SB OFF (11)
noisy signal
good signal
E'
Automatic deviation controlled threshold adjustment
If the system is tuned to stations with a high deviation the noise blanker can trigger on the
higher frequencies of the modulation. To avoid this wrong behavior, which causes noise in
the output signal, the noise blanker offers a deviation-dependent threshold adjustment. By
rectifying the MPX signal a further signal representing the actual deviation is obtained. It is
used to increase the PEAK voltage. The gain of this circuit is programmable in 3 steps
(NBDC) of the stereo decoder-byte (the first step turns off the detector).
Figure 7.
Deviation controlled threshold adjust
VPEAK
[VOP]
00
2.0
01
1.5
10
1.0
11
0.8
20
32.5
45
75
Detector off
DEVIATION [KHz]
Multipath influence on noise blanker
To react on high repetitive spikes caused by a Multipath-situation, the discharge-time of the
VPEAK voltage can be decreased depending on the voltage-level at Pin MPTC. There are
two ways to do this.
36/76
a)
Switch on the linear influence of the Multipath-Level on the PEAK-signal . In this
case the discharge slew rate is 1V/ms. The slew rate is measured with
RDischarge=infinite and VMPTC=2.5V
b)
Activate a function, which switches to the 18k discharge resistor if the MultipathLevel is below 2.5V. If multipath influence on noise blanker is switched ON than
MPF bit has to be set to 0.
TDA7541
Functional description
Noise blanker in AM mode
In AM mode the noise blanker is activated if a spike on the audio signal is bigger than a fixed
threshold. In order to blank the whole spike in AM mode the hold time of the S&H circuit is
much longer than in FM mode (640µs -1,2ms). It is not recommended to use the AM noise
blanker without to use the AMIF noise blanker inside the tuner.
4.3.3
Functional description of the multipath detector
Using the internal multi path detector the audible effects of a multi path condition can be
minimized. A multi path condition is detected by rectifying the 19 kHz spectrum in the field
strength signal. An external capacitor is used to define the attack- and decay-times. The
MPTC pin is used as detector output connected to a capacitor. Using this configuration an
external adaptation to the user's requirement is possible without affecting the "normal" field
strength input (FSTC) for the stereo decoder.
To keep the old value of the multi path detector during an alternative frequency jump, the
MPFAST bit can disconnect the external capacitor.
Selecting MPINT the channel separation is automatically reduced during a multipath
condition according to the voltage appearing at the MPTC pin.
To obtain a good multipath performance an adaptation is necessary. Therefore the gain of
the 19 kHz-band pass is programmable in four steps (MPG) and the rectifier gain is
programmable in four steps (MPRG). The attack- and decay-times can be set by the
external capacitor value and the multipath detector charge current MPCC.
4.3.4
Quality detector
The TDA7541 offers a quality detector output, which gives a voltage representing the FMreception conditions. To calculate this voltage the MPX-noise and the multipath-detector
output are summed according to the following formula:
V Qual = 0.8 ⋅ b ⋅ ( V PEAK – 0.8 ) + a ⋅ ( V REF1 – V MPTC )
The VPEAK signal is described in noise blanker session. The factor 'a' can be programmed
from 0.6 to 1.05 (QDC) and the factor b can be programmed from 6dB to 15dB (QNG). The
quality output voltage can be read at the MUX pin. The MUX pin is a low impedance output
and is able to drive external circuitry as well as simply fed to an AD-converter for RDS
applications.
4.3.5
AFS control and stereo decoder mute
In case of AFS (alternative frequency search) jump it is recommended to set the stereo
decoder in mute condition (SDM) and in addition to set the SEEK mode. Since these two
bits are placed in the first written byte, this can be done in the same write cycle as the PLL
jump. The stereo decoder mute is high impedance mute, which means the charge on the
coupling capacitor will be kept. Simultaneously the pilot detector circuit of the stereo
decoder is switched into hold mode. The SEEK mode is switching the multi path detector
into fast mode. The external capacitor at MPTC is disconnected from multipath detector
which keeps the stereo blend condition, but makes the quality information in fast mode
available at the MUX pin.
37/76
Functional description
TDA7541
4.4
PLL and IF counter section
4.4.1
PLL frequency synthesizer block
This part contains a frequency synthesizer and a loop filter for radio tuning system. Only one
VCO is required to build a complete PLL system for FM world tuning and AM up conversion.
VCO and dividers
The varactor tuned LC oscillator together with the dividers provides the local oscillator signal
for both AM and FM front-end mixers. The VCO has an operating frequency of
approximately 160MHz to 260MHz. In FM mode the VCO frequency is divided (VCOD) by 1,
2 or 3. These dividers generate in-phase and quadrature-phase output signals using in FM
mixer for image rejection.
In AM mode the divided VCO frequency is additional predivided (AMD) by 4, 6, 8 or 10
dependent on selected AM band.
PLL frequency generation for phase comparison
The VCO divided signals applies a two modulus counter (32/33), which is controlled by a 5bit A-divider. The 5-bit register (PC0 to PC4) controls this divider. In parallel the output of the
swallow counter is connected to an 11-bit B-divider. The 11-bit PC register (PC5 to PC15)
controls this divider. Dividing range behind VCO divider:
ƒ VCOdiv = [ 32 • B + A + 32 ] • ƒ REF
Important: For correct operation: A ≤ 32; B ≥ A
Crystal oscillator
The crystal oscillator provides 10.25MHz signal for conversion from IF1 to IF2 as well as
switching signals for ISS- and quality detection filter. Furthermore reference dividers
generate from adjustable crystal frequency (XTAL) reference frequencies for the tuning PLL,
IF counter and FM demodulator.
The various reference frequencies fREF of PLL (RC) can be chosen by IIC-bus.
Three state phase comparator
The phase comparator generates a phase error signal according to phase difference
between fSYN and fREF. This phase error signal drives the charge pump current generator.
Charge pump current generator
This system generator signed pulses of current. The phase error signal decides the duration
and polarity of those pulses. The current absolute values are programmable by register ICP.
In lock detector
After reaching a phase difference about lower than 40nsec the inlock detector is
automatically switching the charge-pump in low current mode (LDENA).
38/76
TDA7541
Functional description
Low noise CMOS op-amp
An internal voltage divider at pin19 connects the positive input of the low noise op-amp. The
charge pump output connects the negative input. This internal amplifier in cooperation with
external components can provide an active filter. The negative input is switchable to two
input pins, to increase the flexibility in application. While the high current mode is activated
LPHC output is switched on.
Antenna DAC
For tuning of FM antenna tank circuit two different modes are available (TVM). One is the
auto-alignment measurement of VCO tuning voltage with offset of 8-bit DAC (TVO). The
other one is an adjustment of 8-bit DAC independent on PLL tracking. For big differences
between VCO tuning voltage and antenna tank control voltage an additional constant offset
voltage can be switched to antenna circuit (TVO+).
4.4.2
IF counter block
The aim of IF counter is it to measure the intermediate frequency of the tuner. The input
signals are the output level of 10.7MHz IF-limiter in FM and output level of 450KHz IF-limiter
in AM.
The grade of integration is adjustable by different measuring cycle times (IFS). The
tolerance of the accepted count value is adjustable too (EW), to reach an optimum
compromise for search speed and precision of the evaluation.
Sampling timer
A sampling timer generates the gate signal for the main counter. The basically sampling
time are in FM 6.25 kHz (tTIM=160 s) and in AM 1 kHz (tTIM=1ms). This is followed by an
asynchronous divider to generate several sampling times.
Intermediate frequency main counter
This counter is an 11 - 21-bit synchronous auto reload down counter. The counter length is
automatic adjusted to the chosen sampling time and the counter mode (FM or AM).
At the start the counter will be loaded with a defined value which is an equivalent to the
divider value (tSample x fIF).
If a correct frequency is applied to the IF counter frequency input at the end of the sampling
time the main counter is changing its state. This is detected by control logic and an external
search stop output is changing from LOW to HIGH.
The IF counter is started only by the in lock information from the PLL part.
4.5
I2C bus interface
The TDA7541 supports the I2C bus protocol. This protocol defines any device that sends
data onto the bus as a transmitter, and the receiving device as the receiver. The device that
controls the transfer is a master and device being controlled is the slave. The master will
always initiate data transfer and provide the clock to transmit or receive operations.
39/76
Functional description
TDA7541
Data transition
Data transition on the SDA line must only occur when the clock SCL is LOW. SDA transitions
while SCL is HIGH will be interpreted as START or STOP condition.
Start condition
A start condition is defined by a HIGH to LOW transition of the SDA line while SCL is at a
stable HIGH level. This "START" condition must precede any command and initiate a data
transfer onto the bus. The device continuously monitors the SDA and SCL lines for a valid
START and will not response to any command if this condition has not been met.
Stop condition
A STOP condition is defined by a LOW to HIGH transition of the SDA while the SCL line is at
a stable HIGH level. This condition terminates the communication between the devices and
forces the bus-interface of the device into the initial condition.
Acknowledge
Indicates a successful data transfer. The transmitter will release the bus after sending 8 bits
of data. During the 9th clock cycle the receiver will pull the SDA line to LOW level to indicate
it receives the eight bits of data.
Data transfer
During data transfer the device samples the SDA line on the leading edge of the SCL clock.
Therefore, for proper device operation the SDA line must be stable during the SCL LOW to
HIGH transition.
Device addressing
To start the communication between two devices, the bus master must initiate a start
instruction sequence, followed by an eight bit word corresponding to the address of the
device it is addressing.
The most significant 6 bits of the slave address are the device type identifier.
The TDA7541 device type is fixed as "110001".
The next significant bit is used to address a particular device of the previous defined type
connected to the bus.
The state of the hardwired PIN 57 defines the state of this address bit. Using this feature up
to two devices could be connected on the same bus. When PIN 57 is connected to VCC via
an external resistor of about 82kΩ the address bit "1" is selected. Please note: in this case
the AM part doesn't work. Otherwise the address bit "0" is selected (FM and AM is working).
Therefore a double FM tuner concept is possible.
The last bit of the start instruction defines the type of operation to be performed:
–
When set to "1", a read operation is selected
–
When set to "0", a write operation is selected
The TDA7541 connected to the bus will compare their own hardwired address with the slave
address being transmitted, after detecting a START condition. After this comparison, the
TDA7541 will generate an "acknowledge" on the SDA line and will do either a read or a write
operation according to the state of R/W bit.
40/76
TDA7541
Functional description
Write operation
Following a START condition the master sends a slave address word with the R/W bit set to
"0". The device will generate an "acknowledge" after this first transmission and will wait for a
second word (the word address field). This 8-bit address field provides an access to any of
the 32 internal addresses. Upon receipt of the word address the TDA7541 slave device will
respond with an "acknowledge". At this time, all the following words transmitted to the
TDA7541 will be considered as Data. The internal address will be automatically
incremented. After each word receipt the TDA7541 will answer with an "acknowledge".
Read operation
If the master sends a slave address word with the R/W bit set to "1", the TDA7541 will
transmit one 8-bit data word. This data word includes the following informations.
bit0 (ISS filter, 1 = ON, 0 = OFF)
bit1 (ISS filter bandwidth, 1 = 80kHz, 0 = 120kHz)
bit2 (STEREO, 1 = STEREO, 0 = MONO)
bit3 (1 = PLL is locked in, 0 = PLL is locked out).
bit4 (fieldstrength indicator, 1 = lower as softmute threshold,
0 = higher as softmute threshold)
bit5 (adjacent channel indicator, 1 = adjacent channel present,
0 = no adjacent channel)
bit6 (deviation indicator, 1 = strong overdeviation present,
0 = no strong overdeviation)
bit7 (deviation indicator, 1 = overdeviation present,
0 = no overdeviation)
41/76
Software specification
5
TDA7541
Software specification
7.1 Chip address and overview
The interface protocol comprises:
–
- start condition (S)
–
- chip address byte
–
- sub address byte
–
- sequence of data (N bytes + Acknowledge)
–
- stop condition (P)
Receive mode
S
1
1
0
0
0
1
D
0 ACK 0
0
I
A4
A3
A2
A1
A0 ACK DATABYTEACK P
0
0
1
D
1 ACK R7 R6 R5 R4
R3
R2
R1
S0 ACK
Transmission mode
S
1
1
S
= Start
P
= Stop
0
P
ACK = Acknowledge
D
= Device address
I
= Auto increment mode
A
= Sub address
R
= Read bit
5.1
Address organization
Table 13.
Address organization
Function
Addr
D7
D6
D5
D4
D3
D2
D1
D0
T PLL chargepump
0
SEEK
ASFC
LM
SDM
LDENA
ICP2
ICP1
ICP0
T PLL counter
1
PC7
PC6
PC5
PC4
PC3
PC2
PC1
PC0
T PLL counter
2
PC15
PC14
PC13
PC12
PC11
PC10
PC9
PC8
T TV
3
TVO7
TVO6
TVO5
TVO4
TVO3
TVO2
TVO1
TVO0
T TV/IF counter
4
FMON
EW6
EW5
IFS4
IFS3
ISSENA
TVO+
TVM
T PLL divider
5
AMD7
AMD6
RC5
RC4
RC3
VCOD2
VCOD1
VCOD0
T AGC
6
LNA7
LNA6
DAGC5
DAGC4
IFAGC3
IFAGC2
RFAGC1
RFAGC0
T Quality AC
7
TISS7
TISS6
TISS5
ACTH4
ACTH3
ACF
BWDEF
ISSBW
T Quality ACM/MP
8
MPTH7
MPTH6
MPAC
MPENA
ACMD
T Quality DEV
9
ISSM
DTH6
DTH5
DWTH4
DWTH3
T Quality MUX/FSU
10
SSTH7
SSTH6
SSTH5
SSTH4
42/76
ACMTH2 ACMTH1
TDEV2
ACMTH0
TDEV1
TDEV0
MUX1
MUX0
TDA7541
Table 13.
Software specification
Address organization (continued)
Function
Addr
D7
D6
D5
D4
D3
D2
D1
D0
T Weak signal mute
11
WMD7
WMD6
WMD5
WMTH4
WMTH3
WMTH2
WBON
ISSON
T AM IF NB
12
IFAGCS
AINT6
AINT5
AINTH4
AINTH3
AINTH2
AINTH1
AINENA
T XTAL adjust
13
SL7
SL6
SL5
XTAL4
XTAL3
XTAL2
XTAL1
XTAL0
T IF adjust
14
IF1G7
IF1G6
IF2Q5
IF2Q4
IF2A3
IF2A2
IF2A1
IF2A0
T IQ adjust/Switch
15
DSB7
DSB6
SWM
SW
PH3
PH2
PH1
PH0
T FM keying AGC
16
FSWO7
FSWO6
RFK
KAGC4
KAGC3
KAGC2
ODCUR
ODENA
SD Roll off
17
LG7
LG6
LG5
LG4
ROC3
ROC2
ROC1
ROC0
SD Stereo blend
18
AMCF7
AMCF6
AMCF5
ASI
PTH
SBC2
SBC1
SBC0
SD High cut
19
DEEMP
HCLT6
HCLT5
HCHT4
HCHT3
SD MP
20
MS
MPFAST
MPINT
MPCC
MPRG3
MPRG2
MPG1
MPG0
SD quality
21
NBFC7
NBFC6
NBDC5
NBDC4
QNG3
QNG2
QDC1
QDC0
SD Audio NB I
22
NBCT7
NBCT6
NBLT5
NBLT4
NBLT3
NBT2
NBT1
NBENA
SD Audio NB II
23
PCM
VCON
NBSMP
NBMP
NBRR2
NBRR1
NBPC
SD Testing
24
T PLL/IFC Testing
25
IFSEXP
1
1
1
1
1
1
T Testing
26
T Testing
27
T Testing
28
T Testing
29
Not used
30
Not used
31
EWEXP
T
Tuner
SD
Stereo decoder
HCMAX2 HCMAX1
HCENA
Data bytes which are unused or dedicated for testing only don't need to be written, because
they are set internally to FEH (power on reset condition). But if somebody it writing these
bytes they must be written to FEH, otherwise some malfunction of the chip can happen.
43/76
Software specification
5.2
TDA7541
Control register function
Table 14.
I2C control bit description
Register
Name
ACF
ACMD
ACMTH
ACTH
AINENA
AINT
Adjacent channel detector filter select
Adjacent channel mute depth
Adjacent channel mute threshold
Adjacent channel detector threshold
AM IF noise blanker enable
AM IF noise blanking time
AINTH
AM IF noise blanker threshold
AMCF
Stereo decoder attenuation @ 3.5kHz
AMD
AM VCO predivider
ASFC
Alternative station frequency check in FM (AGC and weak signal mute on hold)
ASI
BWDEF
DAGC
DEEMP
Audio signal inversion
Enables bit ISSBW for ISS bandwidth control
AM narrow band AGC threshold
Stereo decoder deemphasis
DSB
FM demodulator spike blanker
DTH
Deviation detector threshold for ISS filter “OFF”
DWTH
Deviation detector threshold for ISS filter 120KHz
EW
IF counter frequency error window
EWEXP
Expanded IF counter error window
FMON
Internal switch FM-AM mode
FSWO
Weighted fieldstrength with offset adjust
HCENA
High cut enable
HCHT
Start level high cut
HCLT
Stop level high cut
HCMAX
44/76
Function
Maximum high cut depth
ICP
Charge pump current tuner PLL
IF1G
IF1 Amplifier Gain
IF2A
IF2 LC band pass fine adjust
IF2Q
IF2 LC band pass quality adjust
IFAGC
FM/AM IF AGC threshold
IFAGCS
AM IFAGC threshold shift
IFS
IF counter sampling time
TDA7541
Software specification
Table 14.
I2C control bit description (continued)
Register
Name
Function
IFSEXP
Expanded IF counter sampling time
ISSBW
ISS filter band width select
ISSENA
ISS filter enable
ISSON
ISS filter control mode
ISSM
ISS filter application mode
KAGC
FM keying AGC
LDENA
Lock detector enable tuner PLL
LG
Stereo decoder level gain adjust
LM
FM local mode enable
LNA
AM LNA Pin/FET mode
MPAC
Influence tuner multi path detection on adjacent channel behavior
MPCC
Stereo decoder multi path detector charge current
MPENA
Tuner multi path detector influence on adjacent channel enable
MPFAST Fast mode of multi path information at quality pin
MPG
Multi path detector gain
MPINT
Stereo decoder multi path internal influence enable
MPRG
Stereo decoder multi path detector rectifier gain
MPTH
Tuner multi path detector threshold
MS
MUX
NBENA
Mono/Stereo switch fixed (“Forced Mono”)
Output multiplexer for MUX pin
Audio noise blanker enable
NBCT
Audio noise blanker noise controlled threshold
NBDC
Audio noise blanker deviation control
NBFC
Audio noise blanker field strength control
NBLT
Audio noise blanker low threshold
NBMP
Stereo decoder multi path influence on peak discharge current
NBPC
Audio noise blanker peak charge current
NBRR
Audio noise blanker rectifier discharge resistor
NBSMP
NBT
Strong multi path influence on audio noise blanker
Audio noise blanker time constant
ODCUR
Current for over deviation correction
ODENA
Over deviation correction enable
PC
PCM
Tuner PLL counter
Pilot cancellation mode
45/76
Software specification
Table 14.
TDA7541
I2C control bit description (continued)
Register
Name
PH
IQ mixer phase adjust
PTH
Pilot detector threshold
QDC
Stereo decoder quality detector coefficient
QNG
Stereo decoder quality noise gain
RC
RFAGC
Tuner PLL reference counter
FM/AM RF AGC threshold
RFK
FM RF keying AGC
ROC
Stereo decoder roll off compensation
SBC
Stereo blend control
SDM
Stereo decoder mute enable
SEEK
FM: FMON = 1, ISS time constant change / AM: FMON = 0, AGC2 time constant change
SL
SSTH
SW
S meter slope
Field strength threshold for seek stop
Free programmable switch
SWM
Free programmable switch mode
TDEV
Time constant for deviation detector
TISS
Time constant for ISS filter “ON”/”OFF”
TVM
Tuning voltage offset mode
TVO
Tuning voltage offset
TVO+
Additional fixed tuning voltage offset
VCOD
Tuner VCO divider
VCON
STD VCO “ON/OFF”
WBON
Weather band mode (ISS filter band width 24 kHz)
WMD
Weak signal mute depth
WMTH
Weak signal mute start point threshold
XTAL
46/76
Function
Xtal frequency fine adjust
TDA7541
Software specification
5.3
Data byte specification
Table 15.
Subaddress description
MSB
LSB
Function
I
Table 16.
A4
A3
A2
A1
A0
0
0
0
0
0
Charge pump control
-
-
-
-
-
-
1
0
1
1
1
Audio noise blanker II
-
-
-
-
-
-
0
Page mode “OFF”
1
Page mode enable
Addr 0 TPLL charge pump control (0Bh)
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
0
0
0
Charge pump current = 50µA
0
0
1
Charge pump current = 0.5mA
0
1
0
Charge pump current = 1mA
0
1
1
Charge pump current = 1.5mA
-
-
-
-
1
1
0
Charge pump current = 3mA
1
1
1
Charge pump current = 3.5mA
ICP<2:0>
LDENA
0
Lock detector disable
1
Lock detector enable
SDM
0
Stereo decoder mute disable
1
Stereo decoder mute enable
LM
0
Local mode disable
1
Local mode enable
ASFC
0
Weak signal mute and AGC normal mode in FM
1
Weak signal mute and AGC on hold in FM mode
SEEK
0
ISS time constant at pin30 available, AM SEEK “OFF”
1
ISS time constant at pin31 available, AM SEEK “ON”
47/76
Software specification
Table 17.
TDA7541
Addr 1 TPLL Counter 1 (LSB)
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
PC<7:0>
0
0
0
0
0
0
0
0
LSB = 0
0
0
0
0
0
0
0
1
LSB = 1
0
0
0
0
0
0
1
0
LSB = 2
-
-
-
-
-
-
-
-
-
1
1
1
1
1
1
0
0
LSB = 252
1
1
1
1
1
1
0
1
LSB = 253
1
1
1
1
1
1
1
0
LSB = 254
1
1
1
1
1
1
1
1
LSB = 255
Table 18.
Addr 2 TPLL Counter 2 (MSB)
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
PC<15:8>
0
0
0
0
0
0
0
0
MSB = 0
0
0
0
0
0
0
0
1
MSB = 256
0
0
0
0
0
0
1
0
MSB = 512
-
-
-
-
-
-
-
-
-
1
1
1
1
1
1
0
0
MSB = 64768
1
1
1
1
1
1
0
1
MSB = 65024
1
1
1
1
1
1
1
0
MSB = 65280
1
1
1
1
1
1
1
1
MSB = 65536
Note:
Swallow mode: fVCO/fSYN = LSB + MSB + 32
Table 19.
Addr 3 TV(00h)
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
TVO<7:0>
-
0
0
0
0
0
0
0
Tuning Voltage Offset = 0mV
0
0
0
0
0
0
1
TVO = 25mV
0
0
0
0
0
1
0
TVO = 50mV
-
-
-
-
-
-
-
-
1
1
1
1
1
1
0
TVO = 3150mV
1
1
1
1
1
1
1
TVO = 3175mV
0
-TVO
1
+TVO
48/76
TDA7541
Table 20.
Addr25
Software specification
Addr 4 TV/IF Counter (FM ACh , AM 1Ch)
MSB
LSB
Function
d7
d6
d7
d6
d5
d4
d3
d2
d1
d0
TVM
0
TV is tracking with PLL
1
TV is independing on PLL
TVO+
0
Disable additional TV offset
1
Enable additional TV offset + 3.175V
ISSENA
0
ISS Filter switched off (bypass of filter, wide)
1
ISS filter control enable
IFS<4:3>
1
0
0
tSample = 20.48ms (FM) 128ms (AM )
1
0
1
tSample = 10.24ms (FM) 64ms (AM )
1
1
0
tSample = 5.12ms (FM) 32ms (AM )
1
1
1
tSample = 2.56ms (FM) 16ms (AM )
0
0
0
tSample = 1.28ms (FM) 8ms (AM )
0
0
1
tSample = 0.64ms (FM) 4ms (AM )
0
1
0
tSample = 0.32ms(FM) 2ms (AM )
0
1
1
tSample = 0.16ms (FM) 1ms (AM )
EW<6:5>
1
0
0
Δf = 12.5kHz (FM) 2kHz (AM)
1
0
1
Δf = 25kHz (FM) 4kHz (AM)
1
1
0
Δf = 50kHz (FM) 8kHz (AM)
1
1
1
Δf = 100kHz (FM) 16kHz (AM)
0
0
0
Not valid
0
0
1
Not valid
0
1
0
Not valid
0
1
1
Δf = 6.25kHz (FM) 1kHz (AM)
FMON
0
Select AM mode
1
Select FM mode
49/76
Software specification
Table 21.
TDA7541
Addr 5 TPLL Divider (FM 3Dh , AM 2Dh)
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
VCOD<2:0>
0
0
not valid (only for testing)
0
1
VCO frequency divided by 2
1
0
VCO frequency divided by 3
1
1
original VCO frequency
0
VCO ”I” signal 0 degree
1
VCO “I” signal 180 degree
RC<5:3>
0
1
1
PLL reference frequency 2 kHz
1
0
0
PLL reference frequency 9 kHz
1
0
1
PLL reference frequency 10 kHz (AM)
1
1
0
PLL reference frequency 25 kHz
1
1
1
PLL reference frequency 50 kHz (FM)
AMD<7:6>
0
0
AM VCO predivider ratio 10
0
1
AM VCO predivider ratio 8
1
0
AM VCO predivider ratio 6
1
1
AM VCO predivider ratio 4
50/76
TDA7541
Software specification
Table 22.
Addr 6 AGC (FM 06h, AM 2Ah)
Addr12 MSB
LSB
Function
d7
d7
d6
d5
d4
d3
d2
d1
d0
RFAGC<1:0>
0
0
RFAGC threshold FM V8-10= 80dBµV, AM V3= 92dBµV
0
1
RFAGC threshold FM V8-10= 84dBµV, AM V3= 99dBµV
1
0
RFAGC threshold FM V8-10= 88dBµV, AM V3= 102dBµV
1
1
RFAGC threshold FM V8-10= 92dBµV, AM V3= 104dBµV
IFAGC<3:2>
1
0
0
IFAGC threshold FM V61= 82dBµV , AM V61= 89dBµV
1
0
1
IFAGC threshold FM V61= 88dBµV , AM V61= 95dBµV
1
1
0
IFAGC threshold FM V61= 91dBµV , AM V61= 99dBµV
1
1
1
IFAGC threshold FM V61= 94dBµV , AM V61= 102dBµV
0
0
0
IFAGC threshold FM V61= 82dBµV , AM V61= 79dBµV
0
0
1
IFAGC threshold FM V61= 88dBµV , AM V61= 85dBµV
0
1
0
IFAGC threshold FM V61= 91dBµV , AM V61= 89dBµV
0
1
1
IFAGC threshold FM V61= 94dBµV , AM V61= 92dBµV
DAGC<5:4>
0
0
DAGC V56= 86dBµ
0
1
DAGC V56= 91dBµ
1
0
DAGC V56= 95dBµ
1
1
DAGC V56= 98dBµ
LNA<7:6>
0
0
I4 = 400uA , V54 = 4,5V , AM LNA Pin/FET mode ”OFF”
0
1
I4 = 400uA + 50uA , V54 = 3,5V
1
0
I4 = 400uA + 100uA , V54 = 3,5V
1
1
I4 = 400uA + 150uA , V54 = 3,5V
51/76
Software specification
Table 23.
TDA7541
Addr 7 Quality AC (FM 50h)
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
ISSBW
0
ISS filter fixed band width 120kHz
1
ISS filter fixed band width 80kHz
BWDEF
0
Disable bit ISSBW for ISS filter band width control
1
Enable bit ISSBW for ISS filter band width control
ACF
0
AC highpass frequency 100kHz
1
AC bandpass frequency 100kHz
ACTH<4:3>
0
0
AC detector threshold 0,35V
0
1
AC detector threshold 0,45V
1
0
AC detector threshold 0,55V
1
1
AC detector threshold 0,65V
TISS<7:5>
0
0
0
discharge current 1µA, charge current mid 74µA, narrow 124µA
0
0
1
discharge current 3µA, charge current mid 72µA, narrow 122µA
0
1
0
discharge current 5µA, charge current mid 70µA, narrow 120µA
0
1
1
discharge current 7µA, charge current mid 68µA, narrow 118µA
-
-
-
-
1
1
1
discharge current 15µA,charge current mid 60µA, narrow 110µA
52/76
TDA7541
Table 24.
Software specification
Addr 8 Quality ACM/MP (FM 6Ah)
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
ACMTH<2:0>
0
0
0
AC mute threshold 60mV
0
0
1
AC mute threshold 90mV
0
1
0
AC mute threshold 150mV
-
-
-
-
1
1
0
AC mute threshold 240mV
1
1
1
AC mute OFF
ACMD
0
Adjacent channel mute depth -4dB
1
Adjacent channel mute depth -6dB
MPENA
0
Multipath control “ON”
1
Multipath control “OFF”
MPAC
0
Multipath eliminates ac (MPENA = 0)
1
Multipath eliminates ac and ac+ (MPENA = 0)
MPTH<7:6>
0
0
MP threshold 0.50V
0
1
MP threshold 0.75V
1
0
MP threshold 1.00V
1
1
MP threshold 1.25V
53/76
Software specification
Table 25.
TDA7541
Addr 9 Quality Dev (FM 49h)
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
TDEV<2:0>
0
0
0
charge current 39µA, discharge current 1 µA
0
0
1
charge current 38 µA, discharge current 2 µA
0
1
0
charge current 37 µA, discharge current 3 µA
0
1
1
charge current 36 µA, discharge current 4 µA
-
-
-
-
1
1
0
charge current 33 µA, discharge current 7 µA
1
1
1
charge current 32 µA, discharge current 8 µA
DWTH<4:3>
0
0
DEV threshold for ISS narrow/wide 20kHz
0
1
DEV threshold for ISS narrow/wide 30kHz
1
0
DEV threshold for ISS narrow/wide 40kHz
1
1
DEV threshold for ISS narrow/wide 50kHz
DTH<6:5>
0
0
DEV threshold for ISS filter “OFF” ratio 1.5
0
1
DEV threshold for ISS filter “OFF” ratio 1.4
1
0
DEV threshold for ISS filter “OFF” ratio 1.3
1
1
DEV threshold for ISS filter “OFF” ratio 1
ISSM
0
ISS filter application mode 1
1
ISS filter application mode 2
54/76
TDA7541
Software specification
Table 26.
Addr 10 Quality MUX/FSU (FM 0Eh , AM 0Fh)
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
MUX<1:0>
0
0
Detected multipath information at PIN 23
0
1
Detected adjacent channel information at PIN 23
1
0
Quality information stereo decoder at PIN 23
1
1
FMON=1: Stereo indication at PIN 23
FMON=0: AM IF2 signal at PIN 23
1
Not used
1
Not used
SSTH<7:4>
0
0
0
0
SSTOP = IFC (IF counter status)
0
0
0
1
SSTOP = H if IFC = H & FS > (FM: 0.6V / AM: 1.2V)
0
0
1
0
SSTOP = H if IFC = H & FS >
0
0
1
1
SSTOP = H if IFC = H & FS >
0
1
0
0
SSTOP = H if IFC = H & FS >
-
-
-
1
1
1
Table 27.
1
SSTOP = H if IFC = H & FS > (FM: 4.1V / AM: 4.8V)
Addr 11 Weak Signal Mute (FM A8h)
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
ISSON
0
ISS filter internal control
1
ISS filter forced “ON”
WBON
0
Weather band disable
1
Weather band enable
WMTH<4:2>
0
0
0
Startpoint mute 0
0
0
1
Startpoint mute 1
0
1
0
Startpoint mute 2
-
-
-
-
1
1
0
Startpoint mute 6
1
1
1
Startpoint mute 7
WMD<7:5>
0
0
0
Mute depth 0
0
0
1
Mute depth 1
-
-
-
-
1
0
1
Mute depth 5
-
-
-
-
1
1
1
Mute depth 7
55/76
Software specification
Table 28.
TDA7541
Addr 12 AM IF NB (AM B1h)
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
0
1
0
0
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
0
0
1
0
0
0
1
0
1
0
1
0
1
0
1
Table 29.
AINENA
AM IF noise blanker disable
AM IF noise blanker enable
AINTH<4:1>
not recommended
not recommended
AM IF NB Threshold 50mV
AM IF NB Threshold 62.5mV
AM IF NB Threshold 100mV
AM IF NB Threshold 187.5mV
AINT<6:5>
AM IF NB Time 8µs
AM IF NB Time 11µs
AM IF NB Time 14µs
AM IF NB Time 17µs
IFAGCS
Enable AM IFAGC threshold shift down (check address6)
Disable AM IFAGC threshold shift down
Addr 13 XTAL adjust(80h)
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
XTAL<4:0>
0
0
0
0
0
CLoad 0pF
0
0
0
0
1
CLoad 0.75pF
0
0
0
1
0
CLoad 1.5pF
0
0
0
1
1
CLoad 2.25pF
0
0
1
0
0
CLoad 3pF
-
-
-
-
-
-
1
1
1
1
0
CLoad 22.5pF
1
1
1
1
1
CLoad 23.25pF
SL<7:5>
0
0
0
S meter slope FM = 0.75V/20dB, AM = 1.61V/20dB
0
0
1
S meter slope FM = 0.80V/20dB, AM = 1.75V/20dB
0
1
0
S meter slope FM = 0.85V/20dB, AM = 1.89V/20dB
0
1
1
S meter slope FM = 0.90V/20dB, AM = 1.98V/20dB
1
0
0
S meter slope FM = 0.95V/20dB, AM = 2.04V/20dB
1
0
1
S meter slope FM = 1.0V/20dB, AM = 2.1V/20dB
1
1
0
S meter slope FM = 1.05V/20dB, AM = 2.15V/20dB
1
1
1
S meter slope FM = 1.1V/20dB, AM = 2.20V/20dB
56/76
TDA7541
Table 30.
Software specification
Addr 14 IF2 adjust (FM E8h, AM 08h)
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
IF2A<3:0>
0
0
0
0
Cadj 0pF
0
0
0
1
Cadj 2,2pF
0
0
1
0
Cadj 4,4pF
0
0
1
1
Cadj 6,6pF
0
1
0
0
Cadj 8,8pF
-
-
-
-
1
0
0
0
-
-
-
-
1
1
1
1
Cadj 17,6pF
Cadj 33pF
IF2Q<5:4>
0
0
no Rint , AM Q=28/gain=26dB, FM Q=28/gain=16dB
0
1
Rint =5kOhm, FM Q=3/gain=14dB, BW=150kHz
1
0
Rint =4,1kOhm, FM Q=2,5/gain=14dB, BW=180kHz
1
1
Rint =3,3kOhm, FM Q=2,05/gain=14dB, BW=220kHz
IF1G<7:6>
0
0
IF1 gain 9dB (AM)
0
1
IF1 gain 12dB
1
0
IF1 gain 17dB
1
1
IF1 gain 21dB (FM)
57/76
Software specification
Table 31.
TDA7541
Addr 15 IQ adjust / Switch (FM E7h)
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
PH<3:0>
0
0
0
0
-7 degree
0
0
0
1
-6 degree
0
0
1
0
-5 degree
-
-
-
-
-
0
1
1
1
0 degree
1
0
0
0
1 degree
1
0
0
1
2 degree
-
-
-
-
1
1
1
0
7 degree
1
1
1
1
8 degree
SW
0
S1 LOW output voltage
1
S1 HIGH output voltage
SWM
0
S1 emitter output available
1
S1 open collector output available
DSB<7:6>
0
0
FM demodulator spike cancelation ”OFF”
0
1
Threshold for FM demodulator spike cancelation 630mV
1
0
Threshold for FM demodulator spike cancelation 400mV
1
1
Threshold for FM demodulator spike cancelation 520mV
58/76
TDA7541
Table 32.
Software specification
Addr 16 FM keying AGC (FM 1Dh)
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
ODENA
0
Over deviation correction disable
1
Over deviation correction enable
ODCUR
0
over deviation correction current max=45µA
1
over deviation correction current max=90µA
KAGC<4:2>
0
0
0
KAGC threshold 3,60* V48 /5
0
0
1
KAGC threshold 3,65* V48 /5
0
1
0
KAGC threshold 3,70* V48 /5
0
1
1
KAGC threshold 3,75* V48 /5
1
0
0
KAGC threshold 3,80* V48 /5
1
0
1
KAGC threshold 3,85* V48 /5
1
1
0
KAGC threshold 3,90* V48 /5
1
1
1
Keying AGC “OFF”
RFK
0
RF keying AGC OFF
1
RF keying AGC ON
FSWO<7:6>
0
0
FSW offset OFF
0
1
FSW offset = -75mV
1
0
FSW offset = -150mV
1
1
FSW offset = -192mV
59/76
Software specification
Table 33.
TDA7541
Addr 17 Roll off / Level gain (77h)
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
ROC<3:0>
0
0
0
0
Roll-Off compensation 25.8%
0
0
0
1
Roll-Off compensation 24.0%
0
0
1
0
Roll-Off compensation 22.2%
0
0
1
1
Roll-Off compensation 20.5%
0
1
0
0
Roll-Off compensation 18.8%
0
1
0
1
Roll-Off compensation 17.1%
0
1
1
0
Roll-Off compensation 15.4%
0
1
1
1
Roll-Off compensation 13.8%
1
0
0
0
Roll-Off compensation 12.2%
1
0
0
1
Roll-Off compensation 10.6%
1
0
1
0
Roll-Off compensation 9.0%
1
0
1
1
Roll-Off compensation 7.5%
1
1
0
0
Roll-Off compensation 6.0%
1
1
0
1
Roll-Off compensation 4.5
1
1
1
0
Roll-Off compensation 3,0%
1
1
1
1
Roll-Off compensation 1.6%
LG<7:4>
0
0
0
0
Level gain 0dB
0
0
0
1
Level gain 0.55dB
0
0
1
0
Level gain 1.10dB
-
-
-
-
-
0
1
1
1
Level gain 3.85dB
-
-
-
-
-
1
1
1
1
Level gain 8.25dB
60/76
TDA7541
Table 34.
Software specification
Addr 18 SD Stereoblend / AM corner frequency (0Dh)
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
SBC<2:0>
0
0
0
Stereoblend control at 29% REF5V
0
0
1
Stereoblend control at 33% REF5V
0
1
0
Stereoblend control at 38% REF5V
0
1
1
Stereoblend control at 42% REF5V
1
0
0
Stereoblend control at 46% REF5V
1
0
1
Stereoblend control at 50% REF5V
1
1
0
Stereoblend control at 54% REF5V
1
1
1
Stereoblend control at 58% REF5V
PTH
0
Pilot threshold high
1
Pilot threshold low
ASI
0
Audio inverter “OFF”
1
Audio inverter “ON”
AMCF<7:5>
0
0
0
AM attenuation @ 3.5kHz = 6.3dB
0
0
1
AM attenuation @ 3.5kHz = 7.9dB
0
1
0
AM attenuation @ 3.5kHz = 9.2dB
-
-
-
1
1
0
AM attenuation @ 3.5kHz = 13.1dB
1
1
1
AM attenuation @ 3.5kHz = 13.8dB
61/76
Software specification
Table 35.
TDA7541
Addr 19 SD High cut (2Fh)
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
HCENA
0
High cut “OFF”
1
High cut “ON”
HCMAX<2:1>
0
0
Maximum high cut 10dB
0
1
Maximum high cut 5.5dB
1
0
Maximum high cut 7.5dB
1
1
Maximum high cut 8.5dB
HCHT<4:3>
0
0
Start level high cut @ 42% REF5V
0
1
Start level high cut @ 50% REF5V
1
0
Start level high cut @ 58% REF5V
1
1
Start level high cut @ 66% REF5V
HCLT<6:5>
0
0
Stop level high cut @ 11% VHCHT
0
1
Stop level high cut @ 18.3% VHCHT
1
0
Stop level high cut @ 25.7% VHCHT
1
1
Stop level high cut @ 33% VHCHT
DEEMP
0
Deemphasis 50µs
1
Deemphasis 75µs
62/76
TDA7541
Table 36.
Software specification
Addr 20 SD MP (FM 97h, AM 3Fh)
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
MPG<1:0>
0
0
Multipath detector gain =6dB
0
1
Multipath detector gain =12dB
1
0
Multipath detector gain =9dB
1
1
Multipath detector gain =10.5dB
MPRG<3:2>
0
0
Multipath detector rectifier gain =7,6dB
0
1
Multipath detector rectifier gain =4,6dB
1
0
Multipath detector rectifier gain =0dB
1
1
Multipath detector rectifier gain disabled
MPCC
0
Multipath detector charge current =0,8µA
1
Multipath detector charge current =0,4µA
MPINT
0
Multipath detector internal influence “ON”
1
Multipath detector internal influence “OFF”
MPFAST
0
External time constant (MPTC) enable
1
External time constant (MPTC) disable
MS
0
Forced MONO
1
MONO/STEREO switch automatically
63/76
Software specification
Table 37.
TDA7541
Addr 21 SD Quality (FFM 7Ah, AM FAh)
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
QDC<1:0>
0
0
Quality detector coefficient a=0,6
0
1
Quality detector coefficient a=0,75
1
0
Quality detector coefficient a=0,9
1
1
Quality detector coefficient a=1,05
QNG<3:2>
0
0
Quality noise gain =6dB
0
1
Quality noise gain =9dB
1
0
Quality noise gain =12dB
1
1
Quality noise gain =15dB
NBDC<5:4>
0
0
Noise blanker deviation adjust 2.0V
0
1
Noise blanker deviation adjust 1.5V
1
0
Noise blanker deviation adjust 1.0V
1
1
Noise blanker deviation adjust “OFF”
NBFC<7:6>
0
0
Noise blanker field strength adjust 2.0V
0
1
Noise blanker field strength adjust 1.6V
1
0
Noise blanker field strength adjust 1.4V
1
1
Noise blanker field strength adjust “OFF”
64/76
TDA7541
Table 38.
Software specification
Addr 22 SD NB I (FM 05h, AM 04h)
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
NBENA
0
Audio noise blanker “OFF”
1
Audio noise blanker “ON”
NBT<2:1>
0
0
Audio noise blanking time 38µs
0
1
Audio noise blanking time 25,5µs
1
0
Audio noise blanking time 32µs
1
1
Audio noise blanking time 22µs
NBLT<5:3>
0
0
0
Noise blanker low threshold 280mV
0
0
1
Noise blanker low threshold 261mV
0
1
0
Noise blanker low threshold 242mV
0
1
1
Noise blanker low threshold 223mV
1
0
0
Noise blanker low threshold 204mV
1
0
1
Noise blanker low threshold 185mV
1
1
0
Noise blanker low threshold 166mV
1
1
1
Noise blanker low threshold 147mV
NBCT<7:6>
0
0
Noise blanker noise controlled threshold 1200mV
0
1
Noise blanker noise controlled threshold 950mV
1
0
Noise blanker noise controlled threshold 700mV
1
1
Noise blanker noise controlled threshold 450mV
65/76
Software specification
Table 39.
TDA7541
Addr 23 SD NB II (FM E2h, AM C2h)
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
NBPC
0
Noise blanker peak charge current low
1
Noise blanker peak charge current high
NBRR<2:1>
0
0
Noise rectifier discharge resistor = infinite
0
1
Noise rectifier discharge resistor =56K
1
0
Noise rectifier discharge resistor =33K
1
1
Noise rectifier discharge resistor =18K
NBMP
0
Multipath influence on peak discharge “OFF”
1
Multipath influence on peak discharge “ON” (-3V/ms)
NBSMP
0
Strong multipath influence on peak discharge “OFF”
1
Strong multipath influence on peak discharge “ON”
VCON
0
Stereo decoder VCO “OFF”
1
Stereo decoder VCO “ON”
PCM
0
Pilot cancellation mode : always
1
Pilot cancellation mode : if pilot > pilot threshold
Not used
1
Table 40.
Addr 24, 26, 27, 28, 29 testing (FEh)
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
1
1
1
1
1
1
1
0
Table 41.
Only for testing
Addr 25 Testing (FEh)
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
1
1
1
1
1
0
Only for testing
IFSEXP
0
Enable expand mode of IF sampling time (see addr4)
1
Disable expand mode of IF sampling time
EWEXP
0
Enable expand mode of error window (see addr4)
1
Disable expand mode of error window
66/76
TDA7541
6
Appendix
Appendix
Figure 8.
Block diagram FM part
67/76
Appendix
TDA7541
Figure 9.
68/76
Block diagram VCO
TDA7541
Appendix
Figure 10. Block diagram ISS function
69/76
Appendix
TDA7541
Figure 11. Block diagram AM path
70/76
TDA7541
Appendix
Figure 12. Block diagram stereo decoder
MPXOUT
MPXIN
L
R
MUX
MPTC FSTC
Figure 13. Block diagram audio noise blanker
MPXIN
Stereo
decoder
L/R
NBENA
Monoflop
FM:22-40µs
AM:0.3-1.2ms
NBT
S&H
FMON
VTH
Deviation
detector
140kHz HPF
(2nd. order)
Threshold
generator
NBCT
NBDC
FMDEMOut
PEAK
RECT
FMON
Rectifier
Integrator
discharge control
NBPC
NBMP
NBSMP NBRR
NBLT
Fieldstrenght
adjust
FSTC
NBFC
MPTC
71/76
Appendix
TDA7541
Figure 14. Block diagram multi path detection for stereo decoder
Stereo
blend
FSTC
Attack/Decay
MUX
MPINT
Rectifier
MPCC
FS
Bandpass
19kHz
internal
MPFAST/
SEEK
Rectifier
MPG
MPRG
MPTC
72/76
TDA7541
7
Preliminary application circuit
Preliminary application circuit
Figure 15. Application circuit
73/76
Package information
8
TDA7541
Package information
In order to meet environmental requirements, ST (also) offers these devices in ECOPACK®
packages. ECOPACK® packages are lead-free. The category of second Level Interconnect
is marked on the package and on the inner box label, in compliance with JEDEC Standard
JESD97. The maximum ratings related to soldering conditions are also marked on the inner
box label.
ECOPACK is an ST trademark. ECOPACK specifications are available at: www.st.com.
Figure 16. LQFP64 mechanical data and package dimensions
mm
inch
DIM.
MIN.
TYP.
MAX.
A
MIN.
TYP.
1.60
A1
0.05
A2
1.35
0.063
0.15
0.002
1.40
1.45
0.053
0.22
0.27
0.0066 0.0086 0.0106
0.20
0.0035
B
0.17
C
0.09
D
11.80
12.00
12.20
0.464
D1
9.80
10.00
10.20
0.386
0.006
0.055
0.057
0.0079
0.472
0.480
0.394
0.401
D3
7.50
0.295
e
0.50
0.0197
E
11.80
12.00
12.20
0.464
0.472
0.480
E1
9.80
10.00
10.20
0.386
0.394
0.401
E3
7.50
L
0.45
OUTLINE AND
MECHANICAL DATA
MAX.
0.295
0.60
0.75
0.0177 0.0236 0.0295
L1
1.00
K
0˚ (min.), 3.5˚ (min.), 7˚(max.)
0.0393
ccc
0.080
LQFP64 (10 x 10 x 1.4mm)
0.0031
D
D1
A
D3
A2
A1
48
33
49
32
0.08mm ccc
E
E1
E3
B
B
Seating Plane
17
64
1
16
C
L
L1
e
K
TQFP64
0051434 F
74/76
TDA7541
9
Revision history
Revision history
Table 42.
Document revision history
Date
Revision
19-Jul-2007
1
Initial release.
2
Updated the Figure 1: Block circuit diagram.
Updated/added the values in the Section 3.3: Electrical
characteristics.
Updated the Section 5.3: Data byte specification.
Updated the Figure 15.
Document status promoted from preliminary data to datasheet.
3
Updated in Table 6 the item 13.14 typ. value, and in the Table 8 the
item 38.5 min. value.
Modified the Section 4.3.3 on page 37.
Modified the Table 20 on page 49.
Updated the Figure 12 on page 71.
9-Jan-2008
15-Jan-2008
Changes
75/76
TDA7541
Please Read Carefully:
Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the
right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any
time, without notice.
All ST products are sold pursuant to ST’s terms and conditions of sale.
Purchasers are solely responsible for the choice, selection and use of the ST products and services described herein, and ST assumes no
liability whatsoever relating to the choice, selection or use of the ST products and services described herein.
No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted under this document. If any part of this
document refers to any third party products or services it shall not be deemed a license grant by ST for the use of such third party products
or services, or any intellectual property contained therein or considered as a warranty covering the use in any manner whatsoever of such
third party products or services or any intellectual property contained therein.
UNLESS OTHERWISE SET FORTH IN ST’S TERMS AND CONDITIONS OF SALE ST DISCLAIMS ANY EXPRESS OR IMPLIED
WARRANTY WITH RESPECT TO THE USE AND/OR SALE OF ST PRODUCTS INCLUDING WITHOUT LIMITATION IMPLIED
WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS
OF ANY JURISDICTION), OR INFRINGEMENT OF ANY PATENT, COPYRIGHT OR OTHER INTELLECTUAL PROPERTY RIGHT.
UNLESS EXPRESSLY APPROVED IN WRITING BY AN AUTHORIZED ST REPRESENTATIVE, ST PRODUCTS ARE NOT
RECOMMENDED, AUTHORIZED OR WARRANTED FOR USE IN MILITARY, AIR CRAFT, SPACE, LIFE SAVING, OR LIFE SUSTAINING
APPLICATIONS, NOR IN PRODUCTS OR SYSTEMS WHERE FAILURE OR MALFUNCTION MAY RESULT IN PERSONAL INJURY,
DEATH, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE. ST PRODUCTS WHICH ARE NOT SPECIFIED AS "AUTOMOTIVE
GRADE" MAY ONLY BE USED IN AUTOMOTIVE APPLICATIONS AT USER’S OWN RISK.
Resale of ST products with provisions different from the statements and/or technical features set forth in this document shall immediately void
any warranty granted by ST for the ST product or service described herein and shall not create or extend in any manner whatsoever, any
liability of ST.
ST and the ST logo are trademarks or registered trademarks of ST in various countries.
Information in this document supersedes and replaces all information previously supplied.
The ST logo is a registered trademark of STMicroelectronics. All other names are the property of their respective owners.
© 2008 STMicroelectronics - All rights reserved
STMicroelectronics group of companies
Australia - Belgium - Brazil - Canada - China - Czech Republic - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan Malaysia - Malta - Morocco - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States of America
www.st.com
76/76