STMICROELECTRONICS TDA7540NTR

TDA7540N
AM/FM car radio tuner IC with stereo decoder and
intelligent selectivity system (ISS)
Features
FM-part
■
RF AGC generation by RF and IF detection
■
I/Q mixer for 1st FM IF 10.7MHz with image
rejection
■
Mixer for 2nd IF 450kHz
■
Internal 450KHz bandpass filter with bandwidth
control by ISS
Additional features
■
VCO for world tuning range
■
Fully integrated FM-demodulator with spike
cancellation
■
High performance fast PLL for RDS-System
■
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
■
All functions I2C-Bus controlled
LQFP80
AM-part
■
Wide and narrow AGC generation
■
Mixer for 1st IF 10.7MHz, AM upconversion
■
Mixer for 2nd IF 450kHz, AM downconversion
■
Integrated AM-demodulator
■
AM IF- and audio noise blanking
Stereodecoder
■
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
■
Internal noise blanker with several threshold
controls
Table 1.
Description
The TDA7540N is a high performance tuner
circuit for AM/FM car radio. It contains mixer, IF
amplifier, demodulator for AM and FM,
stereodecoder, 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
Temp range, °C
Package
Packing
TDA7540N
-40 to 85°C
LQFP80 (14x14x1.4mm)
Tube
TDA7540NTR
-40 to 85°C
LQFP80 (14x14x1.4mm)
Tape and reel
November 2007
Rev 1
1/76
www.st.com
1
Contents
TDA7540N
Contents
1
Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2
Pins description and connection diagrams . . . . . . . . . . . . . . . . . . . . . . 8
3
4
2.1
LQFP80 pins connection diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.2
Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Electrical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.1
Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.2
Thermal data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.3
Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Globals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.3.2
FM section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.3.3
AM section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
3.3.4
Stereodecoder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3.3.5
PLL Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
4.1
FM section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
4.1.1
Mixer1, AGC and 1.IF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
4.1.2
Mixer2, limiter and demodulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
4.1.3
Quality detection and ISS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
4.1.4
Soft mute control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
4.2
AM section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
4.3
Stereodecoder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
4.4
4.5
2/76
3.3.1
4.3.1
Decoder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
4.3.2
Functional description of the noise blanker . . . . . . . . . . . . . . . . . . . . . . 32
4.3.3
Functional description of the multipath-detector . . . . . . . . . . . . . . . . . . 33
4.3.4
Quality detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
4.3.5
AFS control and stereo decoder mute . . . . . . . . . . . . . . . . . . . . . . . . . . 34
PLL and IF counter section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
4.4.1
PLL frequency synthesizer block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
4.4.2
IF counter block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
2
I C-Bus interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
TDA7540N
5
Contents
Software specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
5.1
Address organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
5.2
Control register function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
5.2.1
Data byte specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
6
Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
7
Part list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
8
Application circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
9
Application notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
10
Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
11
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
3/76
List of tables
TDA7540N
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.
Table 43.
Table 44.
Table 45.
Table 46.
Table 47.
Table 48.
4/76
Device summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Thermal data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Globals electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
FM section electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
AM section electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Stereodecoder electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
PLL electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Address organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Control register function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Subaddress. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Addr 0 Charge Pump Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Addr 1 PLL counter 1 (LSB) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Addr 2 PLL counter 2 (MSB). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Addr 3,4 TV1,2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Addr 5 IF counter control 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Addr 6 IF counter control 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Addr 7 AM control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Addr 8 quality ISS filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Addr 9 quality detection adjacent channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Addr 10 quality detection multipath. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Addr 11 quality deviation detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Addr 12 softmute control 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Addr 13 softmute control 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Addr 14 VCODIV/PLLREF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Addr 15 FM AGC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Addr 16 AM AGC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Addr 17 FM demodulator fine adjust. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Addr 18 S-meter slider . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Addr 19 IF GAIN/XTAL adjust. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Tank adjust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Addr 21 I/Q FM mixer1 adjust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Addr 22 AM IF noise blanker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Addr 23 switch control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Addr 24 stereodecoder 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Addr 25 stereodecoder 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Addr 26 stereodecoder 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Addr 27 stereodecoder 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Addr 28 stereodecoder 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Addr 29 stereodecoder 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Addr 30 stereodecoder 7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Addr 31 stereodecoder 8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Addr 32 stereodecoder 9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Addr 33 test tuner control 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Addr 34 test tuner control 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Addr 35 test tuner control 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Addr 36 test tuner control 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
TDA7540N
Table 49.
Table 50.
Table 51.
Table 52.
Table 53.
Table 54.
Table 55.
List of tables
Addr 37 test tuner control 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Addr 38 test stereodecoder control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Addr39 test FM demodulator spike blanker and stereo decoder . . . . . . . . . . . . . . . . . . . . 63
Block diagram quality detection principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Functional mode quality detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Part list (application- and measurment circuit) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
5/76
List of figures
TDA7540N
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.
Figure 17.
Figure 18.
Figure 19.
6/76
Block circuit diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
LQFP80 pins connection (top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Trigger threshold vs. VPEAK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Deviation controlled trigger adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Field strength controlled trigger adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Relation between internal and external level-voltagees and setup of stereoblend . . . . . . . 31
Highcut characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Block diagram I/Q mixer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Block diagram VCO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Block diagram keying AGC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Block diagram ISS function. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Block diagram AM part . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Block diagram AM IF noise blanker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Block diagram stereodecoder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Block diagram audio noise blanker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Block diagram multipath detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Block diagram AFS function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Application circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
LQFP80 (14x14x1.40mm) mechanical data and package dimensions. . . . . . . . . . . . . . . . 74
TDA7540N
Block diagram
1
Block diagram
Figure 1.
Block circuit diagram
7/76
Pins description and connection diagrams
TDA7540N
2
Pins description and connection diagrams
2.1
LQFP80 pins connection diagram
GNDVCC2
AMMIX2OUT2
AMMIX2OUT1
FMM1X2IN
VCC2
FMM1X2REF
AMRFAGCTC
IF1AMP2OUT
AMDETC
IF1AMP2IN
AMREFDEMC
VCCIF1
IF1AMP1OUT
IF1REF
IF1AMP1IN
GNDIF1
IF1AGCIN
AMAGC2TC
TEST2
LQFP80 pins connection (top view)
MIX1OUT2
Figure 2.
80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65 64 63 62 61
MIX1 OUT1
1
60
VREF1
TEST1
2
59
AMIF2IN
DEVTC
3
58
MPXW
AMMIX1IN
4
57
GNDDEM
AMMIX1REF
5
56
FMREFDEMC
AMRFAGCOUT
6
55
AMIF2REF
AMPINDR
7
54
AMIF2BPF
FMPINDR
8
53
MPXOUT
FMMIX1IN1
9
52
AFS
GNDRF
10
51
VCCSTEREO
FMMIX1IN2
11
50
MPXIN
TV1
12
49
MUTETC
TV2
13
48
MPTC
ISSSTATUS
14
47
GNDSTEREO
S1
15
46
QUALYOUT
FMAGCTC
16
45
FSWO
S2
17
44
VCC1
VCOB
18
43
L
VCOE
19
42
R
VCCVCO
20
41
GNDVCC1
2.2
Pin description
Pin #
Pin name
Function
1
MIX1OUT1
2
TEST1
Testing I/O pin
3
DEVTC
Deviation detector time constant
4
AMMIX1IN
5
AMMIX1REF
AM mixer1 reference
6
AMRFAGCOUT
Output AM RF AGC
7
AMPINDR
AM pin diode driver output
8
FMPINDR
FM pin diode driver output
9
FMMIX1IN1
Mixer tank 10.7MHz
AM mixer1 input
FM mixer1 input1
LPHC
LPFM
LPAM
VREF2
VCC3
LPOUT
GNDVCC3
SCL
FSTC
SDA
SSTOP
XTALD
ISSTC2
ISSTC1
XTALG
STEREO
AMST/MP
ADJCH
Pin description
Table 2.
8/76
FSU
GNDVCO
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
D06AU1653
TDA7540N
Pins description and connection diagrams
Table 2.
Pin description (continued)
Pin #
Pin name
Function
10
GNDRF
11
FMMIX1IN2
12
TV1
Tuning voltage preselection1
13
TV2
Tuning voltage preselection2
14
ISSSTATUS
15
S1
16
FMAGCTC
17
S2
18
VCOB
VCO input base
19
VCOE
VCO output emitter
20
VCCVCO
VCO supply
21
GNDVCO
VCO ground
22
FSU
23
ADJCH
24
AMST/MP
AM stereo output / ident. multipath output
25
STEREO
Stereo information indication output
26
XTALG
Xtal oscillator to MOS gate
27
ISSTC1
Time constant1 ISS filter switch
28
ISSTC2
Time constant2 ISS filter switch
29
XTALD
Xtal oscillator to MOS drain
30
SSTOP
Search stop output
31
SDA
I2C-Bus data
32
SCL
I2C-Bus clock
33
FSTC
34
GNDVCC3
35
LPOUT
36
VCC3
Supply tuning voltage
37
VREF2
Voltage reference for PLL op amp
38
LPAM
Op amp input to PLL loop filters AM
39
LPFM
Op amp input to PLL loop filters FM
40
LPHC
High current PLL loop filter input
41
GNDVCC1
42
R
Stereodecoder output right
43
L
Stereodecoder output left
44
VCC1
Digital supply
45
FSWO
Weighted fieldstrength output with programmable DC offset
46
Qualyout
RF ground
FM mixer1 input2
ISS filter status output
Free programmable switching output
FM AGC time constant
Free programmable switching output
Unweighted fieldstrength output
Ident. adjacent channel output
S-meter filtering capacitor
VCC3 ground
Op amp output to PLL loop filters
Digital ground
Stereodecoder quality output
9/76
Pins description and connection diagrams
Table 2.
10/76
TDA7540N
Pin description (continued)
Pin #
Pin name
Function
47
GNDSTEREO
Strereodecoder ground
48
MPTC
Multipath time constant
49
MUTETC
50
MPXIN
51
VCCSTEREO
52
AFS
53
MPX/AFAM
MPX output / AM AF output
54
AMIF2BPF
AM IF2 bandpass filter
55
AMIF2REF
Reference voltage AM IF2 amplifier
56
FMREFDEMC
57
GNDDEM
58
MPXW
59
AMIF2IN
Input AM IF2
60
VREF1
Reference 5V
61
GNDVCC2
Analog ground
62
AMMIX2OUT2
AM Tank 450kHz
63
AMMIX2OUT1
AM Tank 450kHz
64
VCC2
65
FMMIX2IN
66
FMMIX2REF
FM IF1 mixer2 reference
67
AMRFAGCTC
AM RF AGC time constant
68
IF1AMP2OUT
IF1 amplifier2 output
69
AMDETC
70
AMREFDEMC
71
IF1AMP2IN
72
VCCIF1
73
IF1AMP1OUT
74
IF1REF
75
IF1AMP1IN
76
GNDIF1
77
IF1AGCIN
78
AMAGC2TC
79
TEST2
80
MIX1OUT2
Weak signal mute time constant
Stereodecoder Input
Stereodecoder supply
Alternative frequency search drive
FM demodulator reference
Ground FM demodulator
MPX Output without ISS filtering
Analog supply
FM IF1 mixer2 input
AM detector capacitor
AM demodulator reference
IF1 amplifier2 input
IF1 supply
IF1 amplifier1 output
IF1 amplifier reference
IF1 amplifier1 input
IF1 ground
IF1 AGC input
AM AGC2 time constant
Testing I/O pin
Mixer tank 10.7MHz
TDA7540N
Electrical specifications
3
Electrical specifications
3.1
Absolute maximum ratings
Table 3.
Absolute maximum ratings
Symbol
VS
3.2
Parameter
Supply voltage
Value
Units
9.5
V
Tamb
Ambient temperature
-40 to 85
°C
Tstg
Storage temperature
-55 to 150
°C
Value
Unit
55
°C/W
Thermal data
Table 4.
Thermal data
Symbol
Rth(j-amb)
Parameter
Thermal resistance junction to ambient
Max.
3.3
Electrical characteristics
3.3.1
Globals
Table 5.
Globals electrical characteristics
(Tamb = 25°C, VCC1 = VCC2 = VCC3 = VCCST= VCCVCO = VCCMIX1 = VCCMIX2 = VCCIF1 =8.5V,
fXtal = 10.25MHz, in application circuit, unless otherwise specified).
Symbol
Parameter
Test conditions
Min.
Typ.
Max.
Unit
Supply
VCC1
Digital supply voltage
7.7
8.5
9
V
VCC2
Analog supply voltage
7.7
8.5
9
V
VCC3
Analog tuning voltage
7.7
8.5
9
V
VCCVCO
VCO supply voltage
7.7
8.5
9
V
VCCMIX1
MIX1 supply voltage
7.7
8.5
9
V
VCCMIX2
MIX2 supply voltage
7.7
8.5
9
V
VCCIF1
IF1 supply voltage
7.7
8.5
9
V
VCCST
Stereo supply voltage
7.7
8.5
9
V
ICC1
Supply current
FM ON
10
12
mA
ICC1
Supply current
AM ON
10
12
mA
ICC2
Supply current
FM ON / VCO:3
65
78
mA
ICC2
Supply current
AM ON
75
90
mA
11/76
Electrical specifications
Table 5.
TDA7540N
Globals electrical characteristics (continued)
(Tamb = 25°C, VCC1 = VCC2 = VCC3 = VCCST= VCCVCO = VCCMIX1 = VCCMIX2 = VCCIF1 =8.5V,
fXtal = 10.25MHz, in application circuit, unless otherwise specified).
Symbol
Parameter
Test conditions
Min.
Typ.
Max.
Unit
ICC3
Supply current
2
3
mA
ICCVCO
Supply current
8
10
mA
ICCMIX1
Supply current
FM ON
8
10
mA
ICCMIX1
Supply current
AM ON
7
8.5
mA
ICCMIX2
Supply current
AM ON
7
8.5
mA
ICCIF1
Supply current
5
6.5
mA
ICCST
Supply current
12
13.5
mA
Reference voltages
VREF1
Internal reference voltage
IREF1 = 0mA
4.8
5
5.2
V
VREF2
Internal reference voltage
IREF2 = 0mA
2.4
2.5
2.6
V
I2C-Bus interface
fSCL
Clock frequency
400
kHz
VIL
Input low voltage
1
V
VIH
Input high voltage
3
5
V
IIN
Input current
-5
5
μA
VO
Output acknowledge voltage
0.4
V
IO = 1.6mA
3.3.2
FM section
Table 6.
FM section electrical characteristics
(Tamb = 25°C, VCC1 = VCC2 = VCC3 = VCCST= VCCVCO = VCCMIX1 = VCCMIX2 = VCCIF1 = 8.5V,
fRF = 98MHz, dev= 40kHz, fMOD = 1kHz, fXtal = 10.25MHz, in application circuit, unless
otherwise specified).
Symbol
Parameter
Test conditions
Min.
Typ.
Max.
Unit
Wide band RF AGC
V9-11
Lower threshold start
V16 = 2.5V
83
85
87
dBμV
V9-11
Upper threshold start
V16 = 2.5V
94
96
98
dBμV
Narrow band IF & keying AGC
V77
Lower threshold start
KAGC = off, V9-11 = 0mVRMS
84
86
88
dBμV
V77
Upper threshold start
KAGC = off, V9-11 = 0mVRMS
96
98
100
dBμV
V77
Lower threshold start with
KAGC
KAGC = max,
V9-11 = 0mVRMS,
ΔfIF=300KHz
96
98
100
dBμV
12/76
TDA7540N
Table 6.
Electrical specifications
FM section electrical characteristics (continued)
(Tamb = 25°C, VCC1 = VCC2 = VCC3 = VCCST= VCCVCO = VCCMIX1 = VCCMIX2 = VCCIF1 = 8.5V,
fRF = 98MHz, dev= 40kHz, fMOD = 1kHz, fXtal = 10.25MHz, in application circuit, unless
otherwise specified).
Symbol
V22
Δ
Parameter
Test conditions
Min.
Typ.
Max.
Unit
Startpoint KAGC
KAGC = max,
V9-11 = 0mVRMS,
ΔfIF=300KHz
fIF1 generates FS level at V22
2.2
V
Control range KAGC
ΔV22= +0.8V
16
dB
RIN
Input resistance
CIN
Input capacitance
10
13
16
2.5
kΩ
pF
AGC time constant output
V16
Max. AGC output voltage
V9-11 = 0mVRMS
VREF1
+VBE
V
V16
Min. AGC output voltage
V9-11 = 50mVRMS
0.5
V
I16
Min. AGC charge current
V9-11 = 0mVRMS,V16 = 2.5V
-16.5
-12.5
-8.5
μA
I16
Max. AGC discharge current
V9-11 = 50mVRMS,V16 = 2.5V
0.8
1.25
1.68
mA
AGC pin diode driver output
I8
AGC OUT, current min.
V9-11 = 0mVRMS, V8 = 2.5V
I8
AGC OUT, current max.
V9-11 = 50 mVRMS, V8 = 2.5V
μA
12
-22
-17
-12
mA
I/Q Mixer1 (10.7MHz)
RIN
Input resistance
differential
10
kΩ
CIN
Input capacitance
differential
4
pF
ROUT
Output resistance
differential
V9,11
Input DC bias
gm
F
CP1dB
100
2.2
Conversion
transconductance
kΩ
2.5
2.8
V
17
ms
Noise figure
400Ω generator resistance
3
dB
1dB compression point
referred to diff. mixer input
100
dBμV
122
dBμV
IIP3
3rd order intermodulation
IQP
I/Q phase adjust
PH
-7
IRR
Image rejection ratio
ratio wanted/image
30
40
dB
IRR
Image rejection ratio
with phase adjust
40
46
dB
5
6
7
dB
+8
°
IF1 Amplifier1 +2 (10.7MHz)
G2
Gain
G1min
Min. gain
IFG1
7.5
9
10.5
dB
G1max
Max. gain
IFG1
16
18
20
dB
13/76
Electrical specifications
Table 6.
TDA7540N
FM section electrical characteristics (continued)
(Tamb = 25°C, VCC1 = VCC2 = VCC3 = VCCST= VCCVCO = VCCMIX1 = VCCMIX2 = VCCIF1 = 8.5V,
fRF = 98MHz, dev= 40kHz, fMOD = 1kHz, fXtal = 10.25MHz, in application circuit, unless
otherwise specified).
Symbol
Min.
Typ.
Max.
Unit
Input resistance
260
330
400
W
ROUT
Output resistance
260
330
400
W
CP1dB
1dB compression point
referred to 330Ω input
105
dBμV
3rd order Intermodulation
ref. to 330Ω input, 9dB gain
126
dBμV
RIN
IIP3
Parameter
Test conditions
Mixer2 (450kHz)
RIN
Input impedance
V65
Max. input voltage
V65
Limiting sensitivity
G
260
S/N = 20dB
Mixer gain
330
400
Ω
119
dBμV
28
dBμV
18
dB
80
dB
Limiter 1 (450kHz)
GLimiter
Gain
Demodulator, audio output
Dev.= 75kHz, V65= 10mVRMS
THD
VMPX
MPX output signal
ROUT
Output impedance
Dev.= 75kHz
400
500
0.1
%
600
mVRMS
50
Ω
|ΔV|min
DC offset fine adjust
DEM, MENA=1
8.5
mV
|ΔV|max
DC offset fine adjust
DEM, MENA=1
264
mV
Dev.= 40kHz,V65 = 10mVRMS
76
dB
S/N
VMPXW
MPXW output signal
Dev.= 75kHz
280
350
420
mVRMS
Quality detection
S-meter, unweighted fieldstrength
V65
Min. input voltage MIX2
V22
Fieldstrength output
V65 = 20dBµV
V22
Fieldstrength output
V65 = 80dBµV, SMSL = 0
2.2
2.6
3.0
V
ΔV22
Voltage per decade
SMSL = 0
0.8
1
1.2
V
ΔV22
Voltage per decade
SMSL = 1
1.2
1.5
1.8
V
ΔV22
S-meter offset
SL, SMSL=1
-15
15
dB
ROUT
Output impedance
520
Ω
TK
14/76
Coefficient temperature
280
30
dBμV
0.1
V
400
0
ppm/K
TDA7540N
Table 6.
Symbol
Electrical specifications
FM section electrical characteristics (continued)
(Tamb = 25°C, VCC1 = VCC2 = VCC3 = VCCST= VCCVCO = VCCMIX1 = VCCMIX2 = VCCIF1 = 8.5V,
fRF = 98MHz, dev= 40kHz, fMOD = 1kHz, fXtal = 10.25MHz, in application circuit, unless
otherwise specified).
Parameter
Test conditions
Min.
Typ.
Max.
Unit
Adjacent channel gain
Gmin
Gain minimum
ACG=0
32
dB
Gmax
Gain maximum
ACG=1
38
dB
Adjacent channel filter
fHP
-3dB frequency highpass
ACF=0
100
kHz
fBP
Centre frequency
ACF=1
100
kHz
f-20dB
Attenuation 20dB
70
kHz
Adjacent channel output
V23
Output voltage low
0.1
V
V23
Output voltage high
4.9
V
ROUT
Output resistance
3.5
4.5
5.5
kΩ
Multipath channel gain
Gmin
Gain minimum
MPG=0
12
dB
Gmax
Gain maximum
MPG=1
23
dB
Multipath bandpass filter
fBP19
Centre frequency
MPF=0
19
kHz
fBP31
Centre frequency
MPF=1
31
kHz
Q
Quality factor
5
8
10
Multipath output
V24
Output voltage low
0.1
V
V24
Output voltage high
4.9
V
3
kΩ
450
kHz
ROUT
Output resistance
ISS (intelligent Selectivity System)
Filter 450kHz
fcentre
Centre frequency
fREF_intern = 450kHz
BW 3dB
Bandwidth, -3dB
ISS80 = 1
70
80
90
kHz
BW 20dB
Bandwidth, -20dB
ISS80 = 1
132
150
168
kHz
BW 3dB
Bandwidth, -3dB
ISS80 = 0
106
120
135
kHz
BW 20dB
Bandwidth, -20dB
ISS80 = 0
220
250
280
kHz
BW 3dB
Bandwidth weather band
ISS30 = 1
20
30
40
kHz
BW 20dB
-20dB weather band
ISS30 = 1
56
80
104
kHz
15/76
Electrical specifications
Table 6.
Symbol
TDA7540N
FM section electrical characteristics (continued)
(Tamb = 25°C, VCC1 = VCC2 = VCC3 = VCCST= VCCVCO = VCCMIX1 = VCCMIX2 = VCCIF1 = 8.5V,
fRF = 98MHz, dev= 40kHz, fMOD = 1kHz, fXtal = 10.25MHz, in application circuit, unless
otherwise specified).
Parameter
Test conditions
Min.
Typ.
Max.
Unit
Adjacent channel ISS filter threshold
VNTH
Internal low threshold
ACNTH
VNTH
Internal high threshold
ACNTH
0.24
0.3
0.36
V
VWTH
Internal low threshold
ACWTH
0.2
0.25
0.3
V
VWTH
Internal high threshold
ACWTH
0.76
0.95
1.14
V
0
V
Multipath threshold
VTHMP
Internal low threshold
MPTH
0.40
0.50
0.60
V
VTHMP
Internal high threshold
MPTH
1.0
1.25
1.5
V
-96
-74
-54
μA
ISS filter time constant
I27,I28
Charge current low mid
TISS, ISSCTL = 1
I27,I28
Charge current high mid
TISS, ISSCTL = 1
I27,I28
Charge current low narrow
TISS, ISSCTL = 1
I27,I28
Charge current high narrow
TISS, ISSCTL = 1
I27,I28
Discharge current low
TISS, ISSCTL = 0
-0.4
1
2.0
μA
I27,I28
Discharge current high
TISS, ISSCTL = 0
10
15
20
μA
V27,V28
Low voltage
ISSCTL = 0
0.1
0.2
V
V27,V28
High voltage
ISSCTL = 1
μA
-60
-165
-124
-87
μA
-110
4.6
μA
4.9
V
ISS filter switch threshold
V27,V28
Threshold ISS on
ISSCTL = 0
3
V
V27,V28
Threshold ISS off
ISSCTL = 0
1
V
V27,V28
Threshold ISS narrow on
ISSCTL = 0
4
V
V27,V28
Threshold ISS narrow off
ISSCTL = 0
2
V
I3
Charge current low
TDEV
-20
-32
-40
μA
I3
Charge current high
TDEV
-30
-39
-48
μA
I3
Discharge current low
TDEV
0.5
1
1.5
μA
I3
Discharge current high
TDEV
5.5
8
10.5
μA
DEVWTH
Internal low threshold
DWTH
30
kHz
DEVWTH
Internal high threshold
DWTH
75
kHz
RATIOmin
Referred to threshold
DTH
1
RATIOmax
Referred to threshold
DTH
1.5
16/76
TDA7540N
Table 6.
Symbol
Electrical specifications
FM section electrical characteristics (continued)
(Tamb = 25°C, VCC1 = VCC2 = VCC3 = VCCST= VCCVCO = VCCMIX1 = VCCMIX2 = VCCIF1 = 8.5V,
fRF = 98MHz, dev= 40kHz, fMOD = 1kHz, fXtal = 10.25MHz, in application circuit, unless
otherwise specified).
Parameter
Test conditions
Min.
Typ.
Max.
Unit
Softmute
VANT
Upper startpoint
SMTH, SMD, SLOPE = 0
10
dBμV
VANT
lower startpoint
SMTH, SMD, SLOPE = 0
3
dBμV
aSMmin
Min. softmute depth
SMD, SLOPE = 0, SMTHUpper
18
dB
aSMmax
Max. softmute depth
SMD, SLOPE = 0, SMTHUpper
36
dB
Mute depth threshold for ISS
SMCTH
filter on
0.2
VACTH
Internal AC mute threshold
ACM
aSMAC
AC mute depth
ACMD
I49
Charge current
-65
I49
Discharge current
aSMTHISS
1
2
dB
60
340
mV
4
10
dB
-47.5
-30
μA
1.5
2.5
4.0
μA
66
69
S/N MPX
VANT = 60dBμV,
dev.= 40kHz,LP=15KHz
deemphasis t = 50μs
(S+N)/N
dB
3.3.3
AM section
Table 7.
AM section electrical characteristics
(Tamb = 25°C, VCC1 = VCC2 = VCC3 = VCCST= VCCVCO = VCCMIX1 = VCCMIX2 = VCCIF1 = 8.5V,
fRF = 98MHz, m= 30%, fMOD = 400kHz, fXtal = 10.25MHz, in application circuit, unless
otherwise specified).
Symbol
Parameter
Test conditions
Min.
Typ.
Max.
Unit
Global
VANT_us
Usable sensitivity
(S+N)/N = 26 dB
25
19
dBµV
IF2 AGC Range
Ref.: VINRF = 60dBμV,
50
52
dB
Signal to Noise Ratio
Ref.: VINRF = 60dBμV
50
55
dB
aIF
IF rejection
Ref: VINRF = 60dBµV,
IF = 10.7MHz
70
80
dB
fAF
Frequency response
Ref.: VINRF = 60dBµV,
= -3 dB
3.6
kHz
0.5
0.3
1.0
0.3
%
ΔVANT
(S+N)/N
ΔVAF
THD
Total Harmonic Distortion
VINRF = 60dBµV, m = 0.8
m = 0.3
VINRF = 120dBµV, m = 0.8
m = 0.3
V53
AF output level
VINRF = 60dBµV
160
180
200
mVRMS
17/76
Electrical specifications
Table 7.
TDA7540N
AM section electrical characteristics (continued)
(Tamb = 25°C, VCC1 = VCC2 = VCC3 = VCCST= VCCVCO = VCCMIX1 = VCCMIX2 = VCCIF1 = 8.5V,
fRF = 98MHz, m= 30%, fMOD = 400kHz, fXtal = 10.25MHz, in application circuit, unless
otherwise specified).
Symbol
Parameter
Test conditions
Min.
Typ.
Max.
Unit
V24
IF output level
VINRF = 60dBµV, m=off
190
mVRMS
V4
Min. RF AGC threshold
Max. RF AGC threshold
WAGC
97
109
dBμV
dBμV
V71
Min. IF AGC threshold
Max. IF AGC threshold
WAGC
96.5
109
dBμV
dBμV
V71
Min. DAGC threshold
Max. DAGC threshold
DAGC
74
96
dBμV
dBμV
|I78max|
AGC2 charge current
seek
CCR
Charge current ratio
seek/seek off
80
100
120
μA
30
AGC voltage driver output
V6
Max. AGC output voltage
V6
Min. AGC output voltage
| I6 |
3.5
V
0.5
AGC current
V
μA
100
AGC pin diode driver output
I7
AGC driver current
-2.6
-2
-1.4
mA
AM Mixer1 (10.7MHz)
RIN
Input resistance
differential
CIN
Input capacitance
differential
ROUT
Output impedance
differential
CP1dB
1dB compression point
referred to diff. mixer input
IIP3
100
kΩ
4
pF
kΩ
100
3rd order intermodulation
112
dBμV
132
dBμV
F
Noise figure
8
dB
A
Gain
26
dB
Cmin
Min. capacitance step
IF1T
0.55
pF
Cmax
Max. capacitance
IF1T
8.25
pF
IF1T
2
pF
C1-80
AM Mixer2 (450kHz)
R71
Input resistance
C71
Input capacitance
CP1dB
IIP3
F
18/76
260
330
400
W
2.5
pF
120
dBμV
3rd order intermodulation
132
dBμV
Noise figure
12
dB
1dB compression point
referred to diff. mixer input
TDA7540N
Table 7.
Electrical specifications
AM section electrical characteristics (continued)
(Tamb = 25°C, VCC1 = VCC2 = VCC3 = VCCST= VCCVCO = VCCMIX1 = VCCMIX2 = VCCIF1 = 8.5V,
fRF = 98MHz, m= 30%, fMOD = 400kHz, fXtal = 10.25MHz, in application circuit, unless
otherwise specified).
Symbol
Parameter
A
Max. gain
ΔA
Gain control range
Test conditions
Min.
Mixer2 tank output
Typ.
Max.
Unit
34
dB
20
dB
Cmin
Min. cap step
IF2T
1.6
pF
Cmax
Max. cap
IF2T
24
pF
IF2T
2
pF
C62-63
IF noise blanking
tbl
Min. blanking time
8
μs
tbl
Max. blanking time
17
μs
Vth
Min internal threshold
10
12.5
15
mV
Vth
Max. internal threshold
150
187.5
225
mV
Vthstep
Threshold step
10
12.5
15
mV
Vdesth
Min. desensitivity threshold
2.9
3.2
3.5
V
Vdesth
Max. desensitivity threshold
3.6
4
4.4
V
3.3.4
Stereodecoder
Table 8.
Stereodecoder electrical characteristics
(Tamb = 25°C, VCC1 = VCC2 = VCC3 = VCCST= VCCVCO = VCCMIX1 = VCCMIX2 = VCCIF1 = 8.5V,
VMPX = 500mVrms mono, f = 1kHz, deemphasis = 50µs, fXtal = 10.25MHz, in application
circuit, unless otherwise specified).
Symbol
Parameter
Test conditions
Min.
Typ.
Max.
Unit
0.5
0.93
Vrms
70
100
130
kΩ
Stereodecoder
Vin
MPX input level
Rin
Input resistance
STD Gain = 2.5 dB
Gmin
Min. Stereodecoder gain
-0.5
0
0.5
dB
Gmax
Max. Stereodecoder gain
3.15
3.75
4.35
dB
Gstep
Stereodecoder gain step
resolution
1
1.25
1.5
dB
SVRR
Supply voltage ripple rejection Vripple = 100mV, f = 1kHz
54
60
dB
50
dB
a
Max. channel separation
THD
Total harmonic distortion
(S+N)/N
Signal plus Noise to Noise
ratio
VMPX = 500mVrms stereo
only L/R
0.02
A-weighted, 19kHz notch
85
0.3
%
dB
19/76
Electrical specifications
Table 8.
TDA7540N
Stereodecoder electrical characteristics (continued)
(Tamb = 25°C, VCC1 = VCC2 = VCC3 = VCCST= VCCVCO = VCCMIX1 = VCCMIX2 = VCCIF1 = 8.5V,
VMPX = 500mVrms mono, f = 1kHz, deemphasis = 50µs, fXtal = 10.25MHz, in application
circuit, unless otherwise specified).
Symbol
Parameter
Test conditions
Min.
Typ.
Max.
Unit
3.1
3.3
3.5
V
Vpuafs
Pull up voltage for AFS pin
Rpuafs
Pull up resistor for AFS pin
VTH1
1. threshold for AFS PIN
2.2
2.4
2.6
V
VTH2
2. threshold for AFS PIN
0.6
0.8
1.0
V
25
kΩ
Mono/stereo-switch
VPTHST1
Pilot threshold voltage
for Mono->Stereo, PTH = 1
6
10
15
mVrms
VPTHST0
Pilot threshold voltage
for Mono->Stereo, PTH = 0
10
14
19
mVrms
VPTHMO1
Pilot threshold voltage
for Stereo->Mono, PTH = 1
4
8
12
mVrms
VPTHMO0
Pilot threshold voltage
for Stereo->Mono, PTH = 0
7
12
16
mVrms
flock
PLL lock range
Pilot magnitude
20 mVrms = 4%
18.9
19.1
kHz
DP
Pilot deviation
Pilot frequency 19kHz
4
30
%
19kHz PLL
Deemphasis- and highcut
tHC50
Deemphasis time constant
DEEMP = 0, DESFT = 1
VLEVEL >> VHCH
50
μs
tHC75
Deemphasis time constant
DEEMP = 1, DESFT = 1
VLEVEL >> VHCH
75
μs
tHC25
Deemphasis time constant
DEEMP = 0, DESFT = 0
VLEVEL >> VHCH
25
μs
tHC37
Deemphasis time constant
DEEMP = 1, DESFT = 0
VLEVEL >> VHCH
37.5
μs
tHC50
Highcut time constant
DEEMP = 0, DESFT = 1
VLEVEL << VHCL
150
μs
tHC75
Highcut time constant
DEEMP= 1, DESFT = 1
VLEVEL << VHCL
225
μs
FAMCMin
Min. AM corner frequency
DEEMP = 0, DESFT = 1
AMCF
1.06
kHz
FAMCMin
Max. AM corner frequency
DEEMP = 0, DESFT = 1
AMCF
3.18
kHz
Stereoblend- and highcut-control
LGmin
Min. level gain
LG
-0.5
0
0.5
dB
LGmax
Max. level gain
LG
4.0
4.7
5.2
dB
LGstep
Level gain step resolution
LG
0.4
0.67
0.9
dB
20/76
TDA7540N
Table 8.
Electrical specifications
Stereodecoder electrical characteristics (continued)
(Tamb = 25°C, VCC1 = VCC2 = VCC3 = VCCST= VCCVCO = VCCMIX1 = VCCMIX2 = VCCIF1 = 8.5V,
VMPX = 500mVrms mono, f = 1kHz, deemphasis = 50µs, fXtal = 10.25MHz, in application
circuit, unless otherwise specified).
Symbol
Parameter
Test conditions
VSBLmin
Min. voltage for mono
SBC
VSBLmax
Max. voltage for mono
SBC
VSBLstep
Step resolution
VHCHmin
Min.
54
Typ.
Max.
Unit
29
33
%VREF1
58
%VREF1
SBC
4.2
%VREF1
Min. voltage for no highcut
VHCH
42
VHCHmax
Max. Voltage for no highcut
VHCH
VHCHstep
Step resolution
VHCLmin
61
46
%VREF1
66
%VREF1
VHCH
8
%VREF1
Min. voltage for full high cut
VHCL, MAXHC = 11
11
VHCLmax
Max. voltage for full high cut
VHCL, MAXHC = 11
VHCLstep
Step resolution
VHCL, MAXHC = 11
31
15
%VHCH
33
%VHCH
7.3
%VHCH
50
dB
Carrier and harmonic suppression at the output
a19
Pilot signal f=19kHz
Vpilot = 50mVrms
a38
Subcarrier f=38kHz
75
dB
a57
Subcarrier f=57kHz
62
dB
a76
Subcarrier f=76kHz
90
dB
Intermodulation(1)
a2
fmod=10kHz, fspur=1kHz
65
dB
a3
fmod=13kHz, fspur=1kHz
75
dB
70
dB
75
dB
Traffic radio(2)
a57
Signal f=57kHz
SCA - Subsidiary communications authorization(3)
a67
Signal f=67kHz
ACI - adjacent channel interference(4)
a114
Signal f=114kHz
95
dB
a190
Signal f=190kHz
84
dB
FM noise blanker
VTRMIN
Min. trigger threshold (5)
VPEAK=0.8V, NBLTH
147
mVOP
VTRMAX
Max. trigger
threshold (5)
VPEAK=0.8V, NBLTH
280
mVOP
VTRSTEP
Trigger threshold step0)
19
mVOP
VTRNOISE
Min. noise controlled trigger
threshold(5)
VPEAK=1.5V, NBCTH
450
mVOP
VTRNOISE
Max. noise controlled
trigger threshold(5)
VPEAK=1.5V, NBCTH
1200
mVOP
21/76
Electrical specifications
Table 8.
Symbol
TDA7540N
Stereodecoder electrical characteristics (continued)
(Tamb = 25°C, VCC1 = VCC2 = VCC3 = VCCST= VCCVCO = VCCMIX1 = VCCMIX2 = VCCIF1 = 8.5V,
VMPX = 500mVrms mono, f = 1kHz, deemphasis = 50µs, fXtal = 10.25MHz, in application
circuit, unless otherwise specified).
Parameter
Test conditions
Min.
Typ.
Max.
Unit
VPEAK
Peak voltage
NBRR = 00, VMPX=0mV
0.5
0.8
1.0
V
VPEAK
Peak voltage
VMPX=50mV, f=150kHz
1.6
1.9
2.1
V
VPEAK
Peak voltage
VMPX=200mV, f=150kHz
2.2
2.5
2.7
V
VPEAKDEV
Min. deviation dependent
peak voltage
VMPX=500mV, NBDTH = 11
0.5
0.8 (off)
1.0
VOP
VPEAKDEV
Max. deviation dependent
peak voltage
VMPX=500mV, NBDTH= 00
1.7
2.0
2.2
VOP
VPEAKFS
Min. fieldstrength controlled
peak voltage
VMPX=0mV, VLEVEL<< VSBL
(fully mono), NBFS = 11
0.5
0.8 (off)
1.0
V
VPEAKFS
Max. fieldstrength controlled
peak voltage
VMPX=0mV, VLEVEL<< VSBL
(fully mono), NBFS = 00
1.7
2.0
2.2
V
TS
Min. blanking time
Signal HOLDN in testmode,
NBT
22
μs
TS
Max. blanking time
Signal HOLDN in testmode,
NBT
38
μs
SRPEAK
Noise rectifier charge
Signal PEAK in testmode,
NBPC=0
10
mV/μs
SRPEAK
Noise rectifier charge
Signal PEAK in testmode,
NBPC=1
20
mV/μs
VRECTADJ
Noise rectifier discharge
adjustment
Signal PEAK in testmode,
NBRR=00, NBSMP=0,
MPPC=0
0.3
V/ms
VRECTADJ
Noise rectifier discharge
adjustment
Signal PEAK in testmode,
NBRR=01, NBSMP=0,
MPPC=0
0.8
V/ms
VRECTADJ
Noise rectifier discharge
adjustment
Signal PEAK in testmode,
NBRR=10, NBSMP=0,
MPPC=0
1.3
V/ms
VRECTADJ
Noise rectifier discharge
adjustment
Signal PEAK in testmode,
NBRR=11, NBSMP=0,
MPPC=0
2.0
V/ms
VADJMP
Noise rectifier adjustment by
multipath
Signal PEAK in testmode,
VMPTC=1V, NBSMP=0,
MPPC=1, NBRR=01
2.5
V/ms
VADJMP
Noise rectifier adjustment by
strong multipath influence
Signal PEAK in testmode,
VMPTC=1V,, NBSMP=1,
MPPC=0, NBRR=01
3.3
V/ms
VADJMP
Noise rectifier adjustment by Signal PEAK in testmode,
multipath and strong multipath VMPTC=1V,, NBSMP=1,
influence
MPPC=1A, NBRR=01
4.5
V/ms
22/76
TDA7540N
Table 8.
Electrical specifications
Stereodecoder electrical characteristics (continued)
(Tamb = 25°C, VCC1 = VCC2 = VCC3 = VCCST= VCCVCO = VCCMIX1 = VCCMIX2 = VCCIF1 = 8.5V,
VMPX = 500mVrms mono, f = 1kHz, deemphasis = 50µs, fXtal = 10.25MHz, in application
circuit, unless otherwise specified).
Symbol
GAMdelay
Parameter
AM delay filter attenuation
Test conditions
Min.
f = 2.2kHz
Typ.
Max.
Unit
2.0
dB
19
kHz
Multipath detector
fCMP
Center frequency of multipath- stereo decoder locked on pilot
bandpass
tone
GBPMP
Min. band pass gain
MPBPG
4
6
8
dB
GBPMP
Max. band pass gain
MPBPG
10
12
14
dB
GRECTMP
Min. rectifier gain
MPRG
-1
0
1
dB
GRECTMP
Max. rectifier gain
MPRG
4.5
7.6
9.5
dB
ICHMP
Rectifier charge current
MPCC = 0
0.5
0.8
1.2
μA
ICHMP
Rectifier charge current
MPCC = 1
0.2
0.4
0.6
μA
IDISMP
Rectifier discharge current
0.3
0.6
0.8
mA
Quality detector
a
Min. MP influence factor
QDC
0.5
0.6
0.7
a
Max. MP influence factor
QDC
0.9
1.05
1.2
A
Min. noise influence factor
QNG
6
dB
A
Max. noise influence factor
QNG
15
dB
1. Intermodulation Suppression
a2 = VO(signal,@1KHz) / VO(spurious, @1KHz) ; fs = (2x10KHz) - 19KHz
a3 = VO(signal,@1KHz) / VO(spurious, @1KHz) ; fs = (3x13KHz) - 38KHz
measured with: 91% stereo signal; 9% pilot signal; fm = 10kHz or 13kHz.
2. Traffic Radio (V.F.) Suppression
a57(V,W,F) = VO(signal,@1KHz) / VO(spurious, @1KHz+/-23KHz)
measured with: 91% stereo signal; 9% pilot signal; fm=1kHz; 5% sub carrier (f=57kHz, fm=23Hz AM, m=60%)
3. SCA ( Subsidiary Communications Authorization )
a67 = VO(signal,@1KHz) / VO(spurious, @9KHz) ; fs = (2x38KHz) - 67KHz
measured with: 81% mono signal; 9% pilot signal; fm=1kHz; 10%SCA – sub carrier ( fS = 67kHz, unmodulated ).
4. ACI (Adjacent Channel Interference )
a114 = VO(signal,@1KHz) / VO(spurious, @4KHz) ; fs = 110KHz - (3x38KHz)
a190 = VO(signal,@1KHz) / VO(spurious, @4KHz) ; fs = 186KHz - (5x38KHz)
measured with: 90% mono signal; 9% pilot signal; fm=1kHz; 1% spurious signal ( fS = 110kHz or 186kHz, unmodulated).
5. All thresholds are measured inTestmode at the quality output. The thresholds are calculated by
VNBTH - VPEAK
VPEAK is adjusted by applying a 150kHz sinewave at MPXIN.
23/76
Electrical specifications
Figure 3.
TDA7540N
Trigger threshold vs. VPEAK
VTH
1200 mV (00)
950 mV (01)
700 mV (10)
450 mV (11)
Noise Controlled Trig. Threshold
Min. Trig. T hreshold
280 mV
8 STEPS
147 mV
Figure 4.
V
1.5 V
0.8 V
Peak
Deviation controlled trigger adjustment
VPEAK
[VOP]
00
2.0
01
1.5
10
1.0
11
0.8
20
Figure 5.
32.5
45
Detector off
DEVIATION [KHz]
75
Field strength controlled trigger adjustment
VPEAK
MONO
STEREO
≈ 3V
2.0V (00)
1.6V (01)
1.4V (10)
NOISE
0.8V
ATC_SB OFF (11)
noisy signal
24/76
good signal
E'
TDA7540N
Electrical specifications
3.3.5
PLL Section
Table 9.
PLL electrical characteristics
(Tamb = 25°C, VCC1 = VCC2 = VCC3 = VCCST= VCCVCO = VCCMIX1 = VCCMIX2 = VCCIF1 = 8.5V,
fRF = 98MHz, dev. = 40kHz, fMOD = 1kHz, fXtal = 10.25MHz, in application circuit, unless
otherwise specified).
Symbol
Parameter
Test conditions
Min.
Typ.
Max.
Unit
VCC3-0.5
V
Output of tuning voltages (TV1,TV2)
VOUT
Output voltage
TVO
0.5
ROUT
Output impedance
TVMODE=0
32
40
48
kΩ
ROUT
Output impedance
TVMODE=1
16
20
24
kΩ
Xtal reference oscillator
Reference frequency
CLoad = 15pF
10.25
MHz
CStep
Min. cap step
XTAL
0.75
pF
Cmax
Max. cap
XTAL
23.25
pF
Δf/f
Deviation versus VCC2
ΔVCC2
= 1V
1.5
ppm/V
Δf/f
Deviation versus temp
-40°C < T < +85°C
0.2
ppm/K
fLO
Loop filter input/output
-IIN
Input leakage current
VIN = GND, PDOUT = Tristate
-0.1
0.1
μA
IIN
Input leakage current
VIN = VREF1
PDOUT = Tristate
-0.1
0.1
μA
VOL
Output voltage Low
IOUT = -0.2mA
0.5
V
VOH
Output voltage High
IOUT = 0.2mA
IOUT
Output current, sink
VOUT = 1V to VCC3-1V
IOUT
Output current, source
VOUT = 1V to VCC3-1V
0.05
VCC30.5
VCC30.05
V
10
mA
-10
mA
50
MHz
Voltage controlled oscillator (VCO)
fVCOmin
Minimum VCO frequency
fVCOmax
Maximum VCO frequency
C/N
Carrier to Noise
260
fVCO= 200MHz, Δf=1KHz,
B=1Hz, closed loop
80
MHz
dBc
SSTOP, INLOCK, ISSSTATUS outputs (open collector)
I = -200μA
V
Output voltage low
V
Output voltage high
-I
Output leakage current
V = 5V
I
Output current, sink
V = 0.5V-5V
0.2
-0.1
0.5
V
5
V
0.1
μA
1
mA
0.5
V
Switching outputs S1, S2 (open collector SMODE=1)
V
Output voltage low
I = -5mA
0.2
25/76
Electrical specifications
Table 9.
Symbol
TDA7540N
PLL electrical characteristics (continued)
(Tamb = 25°C, VCC1 = VCC2 = VCC3 = VCCST= VCCVCO = VCCMIX1 = VCCMIX2 = VCCIF1 = 8.5V,
fRF = 98MHz, dev. = 40kHz, fMOD = 1kHz, fXtal = 10.25MHz, in application circuit, unless
otherwise specified).
Parameter
Test conditions
V
Output voltage high
-I
Output leakage current
V = 5V
I
Output current, sink
V = 0.5V-VCC
Min.
Typ.
-0.5
Max.
Unit
VCC1
V
0.5
μA
7
mA
0.3
V
Switching outputs S1, S2 (Open emitter SMODE=0)
26/76
V
Output voltage low
I = 0μA
0.1
V
Output voltage high
I = 1mA
VCC1-1
I
Output current, sink
V = 5V
V
7
mA
TDA7540N
Functional description
4
Functional description
4.1
FM section
4.1.1
Mixer1, AGC and 1.IF
FM quadrature 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.
The mixer1 tank can be adjusted by software (IF1T). 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, 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,KAGC). The output signal is a controlled current for pin diode attenuator.
A 10.7MHz programmable amplifier (IFG1) correct the IF ceramic insertion loss and the
costumer level plan application.
4.1.2
Mixer2, limiter and demodulator
In this 2nd mixer stage the first 10.7MHz IF is converted into the second 450kHz IF. A multistage limiter generates signals for the complete integrated demodulator including spike
cancellation (DNB). MPX output DC offset versus noise DC level is correctable by software
(DEM), if tuner softmute is activated.
4.1.3
Quality detection and ISS
Fieldstrength
Parallel to mixer2 input a 10.7MHz limiter generates a signal for digital IF counter and a
fieldstrength output signal. This internal unweighted fieldstrength is used for keying AGC,
adjacent channel and multipath detection and is available at PIN22 (FSU) after +6dB buffer
stage. It is possible to combinate the IF counter result with this FSU via programmable
comparator (SSTH). The behaviour of FSU signal can be corrected for DC offset (SL) and
slope (SMSL). The generated unweighted fieldstrength is externally filtered and used for
softmute function and generation of ISS filter switching signal for weak input level (sm).
Adjacent channel detector
The input of the adjacent channel detector is AC coupled from internal unweighted
fieldstrength. A programmable highpass or bandpass (ACF) and amplifier (ACG) as well as
rectifier determines the influences. This voltage is compared with adjustable comparator1
thresholds (ACWTH, ACNTH). The output signal of this comparator generates a DC level at
PIN27 by programmable time constant. Time control (TISS) for a present adjacent channel
27/76
Functional description
TDA7540N
is made by charge and discharge current after comparator1 in an external capacitance. The
charge current is fixed and the discharge current is controlled by I2C Bus. This level
produces digital signals (ac, ac+) in an additional comparator4. The adjacent channel
information is available as analog output signal after rectifier and +8dB output buffer.
Multipath detector
The input of the multipath detector is AC coupled from internal unweighted fieldstrength. A
programmable bandpass (MPF) and amplifier (MPG) as well as rectifier determines the
influences. This voltage is compared with an adjustable comparator2 thresholds (MPTH).
The output signal of this comparator2 is used for the "Milano" effect. In this case the
adjacent channel detection is switched off. The "Milano" effect is selectable by I2C Bus
(MPOFF). The multipath information is available as analog output signal after rectifier and
+8dB output buffer.
450kHz IF narrow bandpass filter (ISS filter)
The device gets an additional 450KHz IF narrow bandpass filter for suppression of noise
and adjacent channel signal influences. This narrow filter has three switchable bandwidthes,
narrow range of 80kHz, mid range of 120kHz and 30KHz for weather band information.
Without ISS filter the IF bandwidth (wide range) is defined only by ceramic filter chain. The
filter is located between mixer2 and 450kHz limiter stage. The centre frequency is matched
to the demodulator center frequency.
Deviation detector
In order to avoid distortion in audio output signal the narrow ISS filter is switched OFF for
present overdeviation. Hence the demodulator output signal is detected. A lowpass filtering
and peak rectifier generates a signal that is defined by software controlled current (TDEV) in
an external capacitance.
This value is compared with a programmable comparator3 thresholds (DWTH, DTH) and
generates two digital signals (dev, dev+). For weak signal condition deviation threshold is
dependent on FSWO.
ISS switch logic
All digital signals coming from adjacent channel detector, deviation detector and softmute
are acting via switching matrix on ISS filter switch. The IF bandpass switch mode is
controlled by software (ISSON, ISS30, ISS80, CTLOFF). The switch ON of the IF bandpass
is also available by external manipulation of voltage at PIN27. Two application modes are
available (APPM).
The conditions are described in Table 52.
4.1.4
Soft mute control
The filtered fieldstrength (FSWO) signal is the reference for mute control. The startpoint and
mute depth are programmable (SMTH, SMD) in a wide range. The time constant is defined
by external capacitance. Additional adjacent channel mute function is supported. A
highpass filter with -3dB threshold frequency of 100kHz, amplifier and peak rectifier
generates an adjacent noise signal from MPX output with the same time constant for
softmute. This value is compared with comparator5 thresholds (ACM). For present strong
adjacent channel the MPX signal is additional attenuated (ACMD).
28/76
TDA7540N
4.2
Functional description
AM section
The up/down conversion is combined with gain control circuit sensing three input signals,
narrow band information at PIN 54, upconversion signal (IF2AGC) at PIN 71and wide band
information (RFAGC) at PIN 4.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 67. The intervention points for AGC (DAGC,WAGC) are programmable by software.
In order to avoid a misbehaviour of AGC intervention point it is important to know that the
DAGC threshold has to be lower than WAGC threshold !
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 increases 900KHz attenuation.In mixer2
the IF1 is down converted into the IF2 450kHz. After filtering by ceramic filter a 450kHz
amplifier is included with an additional gain control of IF2 below DAGC threshold. Time
constant is defined by capacitance at PIN 78.
Mixer1 and mixer2 tanks are software controlled adjustable (IF1T, IF2T).
The demodulator is a peak detector to generate the audio output signal.
A separate output is available for AMIF stereo (AMST).
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,
wich enlarge spike influences on audio signal and makes difficult to remove it in audio path.
The 10.7MHz AM IF signal generates before 10.7 MHz ceramic filter via limitation an
unweighted fieldstrenght signal including slope of noise spike. The comparison of these
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 450KHz AM mixer2. Additionally this funtionality is controlled by narrow AM
fieldstrenght (AINBD).
4.3
Stereodecoder
4.3.1
Decoder
The stereo decoder-part of the TDA7540N (see Figure 14) contains all functions necessary
to demodulate the MPX-signal like pilot tone-dependent MONO/STEREO-switching as well
as "stereoblend" and "highcut". Adaptations like programmable input gain, roll-off
compensation, selectable deemphasis time constant and a programmable field strength
input allow easy adaption to different applications.
The 4th order input filter has a corner frequency of 80kHz and is used to attenuate spikes
and noise and acts as an anti-aliasing filter for the following switch capacitor filters.
29/76
Functional description
TDA7540N
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 TDA7540 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 at least 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 header are trimmed.
In addition to that the FM signal can be inverted.
Deemphasis and highcut
The deemphasis low pass allows to choose between a time constant of 50µs/ 75μs
(DEEMP) and 25μs/37.5μs (DESFT). The highcut control range will be in both cases τHC =
2xτDeemp. Inside the highcut control range (between VHCH and VHCL) the LEVEL signal is
converted into a 5-bit word, which controls the low pass time constant between
τDeemp...3xτDeemp. Thereby the resolution will remain always 5 bits independently of the
absolute voltage range between the VHCH- and VHCL-values.
The highcut function can be switched off by I2C-bus .
In AM mode (AMON = 1) the bits DEEMP and DESFT together with the AM corner
frequency bits (AMCF1...5) can be used as programmable AM frequency response. The
maximum corner frequency is defined by τDeemp , the minimum is defined by 3xτDeemp
19kHz PLL and pilot tone detector
The PLL has the task to lock on the 19kHz 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
TDA7540N via I2C-bus or by reading the STEREO pin (pin 25).
Field strength control
The field strength input is used to control the highcut- and the stereoblend-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 (pin22). Appling a capacitor at
FSTC (pin33) a desired time constant can by reached together with the internal resistor of
10k between FSU pin and FSTC pin.
In addition to that the LEVEL signal is low pass filtered internally in order to suppress
undesired high frequency modulation on the highcut- and stereoblend-function . The filter is
a combination of a 1st-order RC-low pass at 53kHz (working as anti-aliasing filter) and a 1storder switched capacitor low pass at 2.2kHz. The second stage is a programmable gain
stage to adapt the LEVEL signal internally . The gain is widely programmable in 8 steps
from 0dB to 4,7dB (step=0.67dB). These 3bits are located together with the Roll-Off bits in
the "Stereo decoder 8"-byte to simplify a possible adaptation during the production of the
car radio.
30/76
TDA7540N
Functional description
Stereoblend control
The stereoblend 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 (see Figure 6).
To adjust the external LEVEL-voltage to the internal range two values must be defined: the
LEVEL gain LG and VSBL. To adjust the voltage where the full channel separation is
reached (VST) the LEVEL gain LG has to be defined. The following equation can be used to
estimate the gain:
LG = VREF1/FSU@full stereo
The MONO-voltage VMO (0dB channel separation) can be chosen selecting VSBL.
Figure 6.
Relation between internal and external level-voltagees and setup of
stereoblend
The stereo blend function can be switched ON/OFF using bit Addr25<d2>. Please note that
in AM it must be switched in forced mono!
Highcut control
The highcut control set-up is similar to the stereoblend 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 (see Figure 7).
Figure 7.
Highcut characteristics
Lowpass
time constant
3 • Deemp
τ Deemp
VHCL
VHCH
Fieldstrength
31/76
Functional description
4.3.2
TDA7540N
Functional description of the noise blanker
In the automotive environment spikes produced by the ignition or for example 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 22μs and 38μs (programmable). The block diagram of the noise
blanker is given inFigure 15.
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 MPX signal is high pass filtered, amplified and rectified. This second order
high pass filter has a corner-frequency of 140kHz. The rectified signal, RECT, is low pass
filtered to generate a signal called PEAK. Also noise with a frequency 140kHz increases the
PEAK voltage. The resulting voltage can be adjusted by use of the noise rectifier discharge
current. The PEAK voltage is fed to a threshold generator, which adds to the PEAK-voltage
a DC-dependent threshold VTH. Both signals, RECT and PEAK+VTH are fed to a
comparator, which triggers a re-triggerable monoflop. The monoflop's output activates the
sample-and-hold circuits in the signal path for the selected duration.
Automatic noise controlled threshold adjustment (Figure 3)
There are mainly two independent possibilities for programming the trigger threshold:
1.
the low threshold in 8 steps (NBLTH)
2.
and the noise adjusted threshold in 4 steps (NBCTH).
The low threshold is active in combination with a good MPX signal without any noise; the
PEAK voltage is less than 1V. The sensitivity in this operation is high.
If the MPX signal is noisy (low fieldstrength) the PEAK voltage increases due to the higher
noise, which is also rectified. With increasing of the PEAK voltage the trigger threshold
increases, too. This particular gain is programmable in 4 steps (NBCTH).
Automatic threshold control by the stereoblend voltage (Figure 5)
Besides the noise controlled threshold adjustment there is an additional possibility for
influencing the noise blanker trigger threshold using the bits NBFS. This influence depends
on the stereoblend 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 a opportunity to control the PEAK voltage by the
stereo blend function it is implemented.
Over deviation detector (Figure 4)
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
32/76
TDA7540N
Functional description
used to increase the PEAK voltage. Offset and gain of this circuit are programmable in 3
steps (NBDTH) of the stereo decoder-byte (the first step turns off the detector).
Multipath-level
To react on high repetitive spikes caused by a Multipath-situation, the discharge-time of the
PEAK voltage can be decreased depending on the voltage-level at Pin MPout. There are
two ways to do this. One way is to switch on the linear influence of the Multipath-Level on the
PEAK-signal . In this case the discharge slew rate is 1V/ms1). The second possibility is to
activate a function, which switches to the 18k discharge if the Multipath-Level is below 2.5V.
If multipath influence on noise blanker is switched ON than MPF bit has to be set to 0.
1)
The slew rate is measured with RDischarge=infinite and VMPout=2.5V
AM Mode of Noise Blanker
The TDA7540N offers an AM audio noise blanker too.
If the AM noise blanker is used the AM audio delay filter and the AM audio filter must be
switched on. It is not recommented to use the AM noise blanker without to use the AMIF
noiseblanker inside the tuner.
The noise blanker is activated if the spike 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).
4.3.3
Functional description of the multipath-detector
Using the internal Multipath-Detector the audible effects of a multipath condition can be
minimized. A multipath-condition is detected by rectifying the 19kHz spectrum in the
fieldstrength signal. An external capacitor is used to define the attack- and decay-times (see
block diagram, Figure 16). The MP_OUT-pin is used as detector-output connected to a
capacitor of about 47nF. Using this configuration an external adaptation to the user's
requirement is possible without affecting the "normal" fieldstrength input (LEVEL) for the
stereo decoder.
To keep the old value of the Multipath Detector during an AF-jump, the MP-Hold switch can
disconnect the external capacitor. This switch is controlled directly by the AFS-Pin.
Selecting MPION the channel separation is automatically reduced during a multipath
condition according to the voltage appearing at the MP_OUT-pin.
Programming
To obtain a good multipath performance an adaptation is necessary. Therefore the gain of
the first 19kHz-bandpass is programmable in two steps (MPG), the gain of the second
19kHz-bandpass is programmable in four steps (MPBPG) and the rectifier gain is
programmable in four steps(MPRG). Please note that the frequency of the first multipath
bandpass (MPF) must be set to 19kHz! 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 TDA7540N 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:
33/76
Functional description
TDA7540N
VQual = 0.8b (VNoise-0.8 V)+ a (VREF1-VMpout).
The noise-signal is the PEAK-signal without additional influences (see noise blanker
description). 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 output is a low impedance output 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
The TDA7540N is supplied with several functionality to support AF-checks using the stereo
decoder. The additional pin (AFS) is implemented in order to speed up the stereo decoder
AF-functions compared to IIC controlling.
The block diagramm of AFS function is shown in Figure 17.
In order to separate the different functions of the AFS pin, two different logic thresholds are
implemented. Below the higher threshold voltage (2.4V) only the multipath-detector is
switched into small time constant (internal logical signal MPfast).
Below the lower threshold voltage (0.8V) the full AFS function is activated. The MPXIN pin is
switched into high impedance mode (internal signal AFSMute), which avoids any clicks
during the jump condition. If the stereo decoder is not muted, it is possible at the same time
to evaluate the noise- and multipath-content of the alternate frequency using the Quality
detector output.
Furthermore the AFS pin does also freeze the condition of pilot locking and magnitude
(internal signal PDhold). The Pdhold signal is defined by Vth1 or Vth2, dependent on the
PDH signal.
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 the radio tuning system. Only
one VCO is required to build a complete PLL system for FM world tuning and AM
upconversion (Figure 9). For auto search stop operation an IF counter system is available.
The PLL counter works in a two stages configuration. The first stage is a swallow counter
with a two modulus (32/33) precounter. The second stage is an 11-bit programmable
counter.
The circuit receives the scaling factors for the programmable counters and the values of the
reference frequencies via an I2C-Bus interface.The reference frequency is generated by an
adjustable internal (XTAL) oscillator followed by the reference divider. The main reference
and step-frequencies are free selectable (RC, PC).
Output signals of the phase detector are switching the programmable current sources. The
loop filter integrates their currents to a DC voltage.
The values of the current sources are programmable by 6 bits also received via the I2C Bus
(A, B, CURRH, LPF).
To minimize the noise induced by the digital part of the system, a special guard
configuration is implemented.
The loop gain can be set for different conditions by setting the current values of the
chargepump generator.
34/76
TDA7540N
Functional description
Frequency generation for phase comparison
The RF signals applies a two modulus counter (32/33) pre-scaler, which is controlled by a 5bit A-divider. The 5-bit register (PC0 to PC4) controls this divider. In parallel the output of the
prescaler connects to an 11-bit B-divider. The 11-bit PC register (PC5 to PC15) controls this
divider
Dividing range behind VCO divider:
fVCOdiv = [33 x A + (B + 1 - A) x 32] x fREF
fVCOdiv = (32 x B + A + 32) x fREF
Important: For correct operation: A ≤ 32; B ≥ A
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 generators signed pulses of current. The phase error signal decides the
duration and polarity of those pulses. The current absolute values are programmable by A
register for high current and B register for low current.
Inlock detector
Switching the chargepump in low current mode can be done either via software or
automatically by the inlock detector, by setting bit LDENA to "1".
After reaching a phase difference about lower than 40nsec the chargepump is forced in low
current mode. A new PLL divider alternation by I2C-Bus will switch the chargepump in the
high current mode.
Low noise CMOS op-amp
An internal voltage divider at pin VREF2 connects the positive input of the low noise opamp. 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 three input pins, to increase the flexibility in application. This feature allows two
separate active filters for different applications.
While the high current mode is activated LPHC output is switched on.
4.4.2
IF counter block
The aim of IF counter is to measure the intermediate frequency of the tuner for AM and FM
mode. The input signal for FM and AM upconversion is the same 10.7MHz IF level after
limiter. AM 450KHz signal is coming from narrow filtered IF2 before demodulation. A switch
controlled by IF counter mode (IFCM) is choosing the input signal for IF counter.
The grade of integration is adjustable by eight different measuring cycle times. The
tolerance of the accepted count value is adjustable, to reach an optimum compromise for
search speed and precision of the evaluation.
The IF-counter mode
The IF counter works in 3 modes controlled by IFCM register.
35/76
Functional description
TDA7540N
Sampling timer
A sampling timer generates the gate signal for the main counter. The basically sampling
time are in FM mode 6.25kHz (tTIM=160μs) and in AM mode 1kHz (tTIM=1ms). This is
followed by an asynchronous divider to generate several sampling times.
Intermediate frequency main counter
This counter is a 11 - 21-bit synchronous autoreload down counter. Five bits (CF) are
programmable to have the possibility for an adjust to the centre frequency of the IF-filter.
The counter length is automatic adjusted to the chosen sampling time and the counter mode
(FM, AM-UPC, 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 from 0h to 1FFFFFh.
This is detected by a control logic and an external search stop output is changing from LOW
to HIGH. The frequency range inside which a successful count result is adjustable by the
EW bits.
tCNT = (CF + 1696+1) / fIF
FM mode
tCNT = (CF + 10688+1) / fIF
AM up conversion mode
tCNT = (CF + 488+1) / fIF
AM mode
Counter result succeeded:
tTIM ≥ tCNT - tERR
tTIM ≤ tCNT + tERR
Counter result failed:
tTIM > tCNT + tERR
tTIM < tCNT - tERR
tTIM = IF timer cycle time (sampling time)
tCNT = IF counter cycle time
tERR = discrimination window (controlled by the EW registers)
The IF counter is only started by inlock information from the PLL part. It is enabled by
software (IFENA).
Adjustment of the measurement sequence time
The precision of the measurements is adjustable by controlling the discrimination window.
This is adjustable by programming the control registers EW.
The measurement time per cycle is adjustable by setting the registers IFS.
Adjust of the frequency value
The center frequency of the discrimination window is adjustable by the control registers CF.
36/76
TDA7540N
4.5
Functional description
I2C-Bus interface
The TDA7540N 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.
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 receive 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 TDA7540N 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 59 defines the state of this address bit. So up to two devices
could be connected on the same bus. When PIN 59 is connected to VCC2 and a resistor at
PIN 55 versus ground of about 5.6k Ohm the address bit “1” is selected. In this case the AM
part doesn’t work. Otherwise the address bit “0” is selected (FM and AM is working).
Therefor a double FM tuner concept is possible.
37/76
Functional description
TDA7540N
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 TDA7540N 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 TDA7540N 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.
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 64 internal addresses.
Upon receipt of the word address the TDA7540N slave device will respond with an
"acknowledge". At this time, all the following words transmitted to the TDA7540N will be
considered as Data. The internal address will be automatically incremented up to hex40 in
page mode. Than again subaddresse hex60 has to be transmitted for following registers
above 32.
After each word receipt the TDA7540N will answer with an "acknowledge".
Read operation
If the master sends a slave address word with the R/W bit set to "1", the TDA7540N will
transit 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)
38/76
TDA7540N
Software specification
5
Software specification
The interface protocol comprises:
- start condition (S)
- chip address byte
- subaddress byte
- sequence of data (N bytes + Acknowledge)
- stop condition (P)
The pagermode is only working up to byte 31. After byte 31 it is need to send again the chip
address followed by the subaddress 32 and the databytes starting from 32 up to 39!
5.1
Address organization
Table 10.
Address organization
Function
Addr
7
6
5
4
3
2
1
0
CHARGEPUMP
0
FMSEEK
CURRH
B1
B0
A3
A2
A1
A0
1
PC7
PC6
PC5
PC4
PC3
PC2
PC1
PC0
2
PC15
PC14
PC13
PC12
PC11
PC10
PC9
PC8
TV1
3
TV1O7
TV1O6
TV1O5
TV1O4
TV1O3
TV1O2
TV1O1
TV1O0
TV2
4
TV2O7
TV2O6
TV2O5
TV2O4
TV2O3
TV2O2
TV2O1
TV2O0
IFC CTRL 1
5
LDENA
CASF
IFCM1
IFCM0
IFENA
IFS2
IFS1
IFS0
IFC CTRL 2
6
EW2
EW1
EW0
CF4
CF3
CF2
CF1
CF0
AM CTL
7
LM
TVMODE
TV2WB
TV1WB
AMD1
AMD0
AMST
AMSEEK
QUALITYISS
8
TISS2
TISS1
TISS0
---
ISS30
ISS80
ISSON
CTLOFF
QUALITY AC
9
ACNTH1
ACNTH0 ACWTH2 ACWTH1 ACWTH0
ACG
ACF
---
QUALITY MP
10
MPAC
APPM2
APPM1
MPTH1
MPTH0
MPG
MPF
MPOFF
QUALITYDEV
11
BWCTL
DTH1
DTH0
DWTH1
DWTH0
TDEV2
TDEV1
TDEV0
MUTE1
12
MENA
SMD3
SMD2
SMD1
SMD0
SMTH2
SMTH1
SMTH0
MUTE2
13
F100K
ACM3
ACM2
ACM1
ACM0
ACMD1
ACMD0
SMCTH
VCO/PLLREF
14
LPF
AMON
RC2
RC1
RC0
VCOD2
VCOD1
VCOD0
PLL COUNTER
39/76
Software specification
Table 10.
TDA7540N
Address organization (continued)
Function
Addr
7
6
5
4
3
2
1
0
FMAGC
15
RFKAGC
KAGC2
KAGC1
KAGC0
IFAGC1
IFAGC0
RFAGC1
RFAGC0
AMAGC
16
DAGC3
DAGC2
DAGC1
DAGC0
WAGC3
WAGC2
WAGC1
WAGC0
DEM ADJ
17
DNB1
DNB0
DEM5
DEM4
DEM3
DEM2
DEM1
DEM0
LEVEL
18
ODSW
ODCUR
SMSL
SL4
SL3
SL2
SL1
SL0
IF1/XTAL
19
XTAL4
XTAL3
XTAL2
XTAL1
XTAL0
IFG11
IFG10
XTLIM
TANK ADJ
20
IF1T3
IF1T2
IF1T1
IF1T0
IF2T3
IF2T2
IF2T1
IF2T0
I/Q ADJ
21
SMO1
SMO0
---
---
PH3
PH2
PH1
PH0
AMIFNB
22
AINT1
AINT0
AINBD1
AINBD0
AINBT3
AINBT2
AINBT1
AINBT0
SCTRL
23
SSTH3
SSTH2
SSTH1
SSTH0
S2MODE
S2
S1MODE
S1
STD1
24
STVCO1
STVCO0
NBT1
NBT0
SI
TFCKL
NBFT
TSMA
STD2
25
STING1
STING0
DEEMP
PTH
NBPC
MS
STDON
STDM
STD3
26
NBDTH1
NBDTH0
NBON
NBCTH1
NBCTH0
NBLTH2
NBLTH1
NBLTH0
STD4
27
NBSMP
VHCL1
VHCL0
VHCH1
VHCH0
STD5
28
MPPC
QDC1
QDC0
NBFS1
NBFS0
STD6
29
MPRG1
MPRG0
MPCC
MPION
STD7
30
AMAF
LG2
LG1
LG0
ROC3
STD8
31
AMNBD
PDH
STD9
32
AMCF4
AMCF3
AMCF2
TESTTU1
33
OUT20
ISSIN
TESTTU2
34
OUT7
TESTTU3
35
TESTTU4
MAXHC1 MAXHC0
SBC1
SBC0
NBRR1
NBRR0
ROC2
ROC1
ROC0
AFSM
AFSON
QNG1
QNG0
AMCF1
AMCF0
DESFT
---
---
TOUT
TIN1
CLKSEP
TEST3
TEST2
TEST1
OUT6
OUT5
OUT4
OUT3
OUT2
OUT1
OUT0
---
TINACM
TINMP
TINAC
OUT11
OUT10
OUT9
OUT8
36
OUT19
OUT18
OUT17
OUT16
OUT15
OUT14
OUT13
OUT12
TESTTU5
37
TIN2
OUT27
OUT26
OUT25
OUT24
OUT23
OUT22
OUT21
TESTSTD
38
---
---
---
TST
FMDEMSB
39
VCOM
PCM
SBW
SBT
5.2
AMNBFO AMNBHP
MPBPG1 MPBPG0
MUXST3 MUXST2 MUXST1 MUXST0
---
SBSH
SBA
SBTO
Control register function
Table 11.
Control register function
Register Name
A
Function
Charge pump high current
ACF
Adjacent channel filter select
ACG
Adjacent channel filter gain
ACM
Threshold for startpoint adjacent channel mute
ACMD
40/76
SBC2
HCON
Adjacent channel mute depth
TDA7540N
Software specification
Table 11.
Control register function (continued)
Register Name
Function
ACNTH
Adjacent channel narrow band threshold
ACWTH
Adjacent channel wide band threshold
AFSM
AFS influence on stereodecoder mute
AFSON
AFS Pin enable
AINBD
AM IF noise blanker desensitivity
AINBT
AM IF noise blanker threshold
AINT
AM IF noise blanking time
AMAF
AM audio filter
AMD
AM prescaler
AMCF
AM corner frequency
AMIN
AM IF1 input select
AMNBD
AM audio delay for noise blanking
AMON
AM-FM switch
AMSEEK
Set short time constant of AGC in AM seek mode
AMST
AM stereo select
APPM
Application mode quality detection
B
BWCTL
CASF
CF
Charge pump low current
ISS filter fixed bandwith (ISS80) in automatic control
Check alternative station frequency
Center frequency IF counter
CLKSEP
Clock separation (only for testing)
CTLOFF
Switch off automatic control of ISS filter
CURRH
Set current high charge pump
DAGC
DEEMP
DEM
AM narrow band AGC threshold
Stereodecoder deemphasis
Demodulator offset
DESFT
Stereodecoder deemphasis shift
DEVM
Deviation detector mode
DNB
Demodulator spike blanking threshold
DTH
Deviation detector threshold for ISS filter “OFF”
DWTH
EW
Deviation detector threshold for ISS filter narrow/wide
Frequency error window IF counter
F100K
Corner frequency of AC-mute high pass filter
FMSEEK
ISS time constant change in FM seek mode
HCON
High cut enable
41/76
Software specification
Table 11.
TDA7540N
Control register function (continued)
Register Name
IF1T
FM/AM mixer1 tank adjust
IF2T
AM mixer2 tank adjust
IFAGC
FM IF AGC
IFCM
IF counter mode
IFENA
IF counter enable
IFG
IF1 amplifier gain (10.7MHz)
IFS
IF counter sampling time
ISSIN
Test input for ISS filter
ISSON
ISS filter “ON”
ISS30
ISS filter 30KHz weather band
ISS80
ISS filter narrow/mid switch
KAGC
FM keying AGC
LDENA
Lock detector enable
LG
Level gain adjust in stereodecoder
LM
Local mode FM seek stop
LPF
Loop filter input select
MAXHC
Maximum high cut
MENA
Softmute enable
MPAC
Adjacent channel control by multipath
MPCC
Multipath detector charge current
MPBPG
Multipath detector bandpass filter gain
MPF
Multipath filter frequency
MPG
Multipath filter gain
MPION
Multipath internal influence enable
MPOFF
Multipath control “OFF”
MPPC
Multipath influence on peak discharge current
MPRG
Multipath detector rectifier gain
MPTH
Multipath threshold
MS
42/76
Function
Mono/Stereo switch automatically
MUXST
Test multiplexer output stereodecoder
NBCTH
Noise blanker noise controlled threshold
NBDTH
Noise blanker deviation controlled threshold
NBFS
Field strength controlled noise blanker
NBFT
AM noise blanker fixed threshold
NBLTH
Noise blanker low threshold
TDA7540N
Software specification
Table 11.
Control register function (continued)
Register Name
Function
NBON
Noise blanker enable
NBPC
Noise blanker peak charge current
NBRR
Noise blanker rectifier discharge resistor
NBSMP
NBT
Strong multipath influence on noise blanker on/off
Noise blanker time
ODCUR
Current for overdeviation-correction
ODSW
Overdeviation-correction enable
OUT
PC
Test output (only for testing)
Counter for PLL (VCO frequency)
PCM
Pilot cancellation mode
PDH
PD hold activation
PH
I/Q mixer phase adjust
PTH
Pilot threshold
QDC
Quality detector coefficient
QNG
Quality noise gain
RC
RFAGC
RFKAGC
ROC
S
Reference counter PLL
FM RF AGC
FM RF keying AGC
Roll-Off compensation
Two mode switching output enable
SBA
FM demodulator spike blanker attack mode
SBC
Stereoblend control
SBSH
SBT
FM demodulator spike blanker sample&hold mode
FM demodulator spike blanker test mode
SBTO
FM demodulator spike blanker toggle mode
SBW
FM demodulator spike blanker window mode
SI
Signal invertion
SL
S meter slider
SMODE
Two mode switching output
SMCTH
Softmute capacitor threshold for ISS “ON”
SMD
Softmute depth threshold
SMO
Softmute reference voltage offset
SMSL
S meter slope
SMTH
Softmute startpoint threshold
SSTH
Unweighted fieldstrenght threshold for seek stop
43/76
Software specification
Table 11.
TDA7540N
Control register function (continued)
Register Name
STDON
Stereodecoder on/off if muted
STDM
Stereodecoder mute enable
STING
Stereodecoder ingain
STVCO
Stereodecoder VCO adjust
TDEV
Time constant for deviation detector
TEST
Testing PLL/IFC (only for testing)
TFCKL
TIN
TINAC
TINACM
TINMP
Fast clock for testing audioprocessor
Switch FSU PIN to TEST input (only for testing)
Test input adjacent channel (only for testing)
Test input adjacent channel mute (only for testing)
Test input multipath(only for testing)
TISS
Time constant for ISS filter “ON”/”OFF”
TMSA
Test mode stereodecoder and audioprocessor
TOUT
Switch FSU PIN to Test output (only for testing)
TST
Test stereodecoder enable
TVMODE
Tuning voltage offset mode
TVO
Tuning voltage offset for prestage
TVWB
Tuning voltage offset for prestage (weather band mode)
VCOD
VCO divider
VCOM
Stereodecoder VCO mode
VCOON
44/76
Function
Enable Stereo Decoder VCO
VHCH
Start level high cut
VHCL
Stop level high cut
WAGC
AM wide band AGC
XTAL
Xtal frequency adjust
XTLIM
Xtal amplitude limitation
TDA7540N
Table 12.
Software specification
Subaddress
MSB
LSB
Function
I
A5
A4
A3
A2
A1
A0
0
0
0
0
0
0
Charge pump control
-
-
-
-
-
-
-
1
0
0
0
0
0
STD9
-
-
-
-
-
-
-
1
0
0
1
1
1
FMDEMSB
0
Page mode “OFF”
1
Page mode enable
5.2.1
Data byte specification
Table 13.
Addr 0 Charge Pump Control
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
0
0
0
0
High current = 0mA
0
0
0
1
High current = 0.5mA
0
0
1
0
High current = 1mA
0
0
1
1
High current = 1.5mA
-
-
-
-
-
1
1
1
1
High current = 7.5mA
0
0
Low current = 0µA
0
1
Low current = 50µA
1
0
Low current = 100µA
1
1
Low current = 150µA
0
Select low current
1
Select high current
0
ISS time constant at PIN 27 available, FMSEEK “OFF”
1
ISS time constant at PIN 28 available, FMSEEK “ON”
45/76
Software specification
Table 14.
TDA7540N
Addr 1 PLL counter 1 (LSB)
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
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 15.
Addr 2 PLL counter 2 (MSB)
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
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
Swallow mode: fVCO/fSYN = LSB + MSB + 32
Table 16.
Addr 3,4 TV1,2
MSB
LSB
Function
d7
-
d6
d5
d4
d3
d2
d1
d0
0
0
0
0
0
0
0
Tuning Voltage Offset = 0
0
0
0
0
0
0
1
TVO = 25mV
0
0
0
0
0
1
0
TVO = 50mV
-
-
-
-
-
-
-
-
1
1
1
1
1
1
1
TVO = 3175mV
0
-TVO
1
+TVO
46/76
TDA7540N
Table 17.
Software specification
Addr 5 IF counter control 1
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
0
0
0
tSample = 20.48ms (FM)128ms (AM )
0
0
1
tSample = 10.24ms (FM)64ms (AM )
0
1
0
tSample = 5.12ms (FM)32ms (AM )
0
1
1
tSample = 2.56ms (FM)16ms (AM )
1
0
0
tSample = 1.28ms (FM)8ms (AM )
1
0
1
tSample = 640µs (FM)4ms (AM )
1
1
0
tSample = 320µs (FM)2ms (AM)
1
1
1
tSample = 160µs (FM)1ms (AM )
0
IF counter disable / stand by
1
IF counter enable
0
0
Not valid
0
1
IF counter FM mode
1
0
IF counter AM mode (450KHz)
1
1
IF counter AM mode (10.7MHz)
0
Disable mute & AGC on hold in FM mode
1
Enable mute & AGC on hold in FM mode
0
Lock detector disable
1
Lock detector enable
Table 18.
Addr 6 IF counter control 2
MSB
LSB
Function
d7
-
-
-
d6
-
-
-
d5
-
-
-
d4
d3
d2
d1
d0
0
0
0
0
0
fCenter = 10.60625MHz (FM) / 10.689MHz ; 449KHz (AM)
0
0
0
0
1
fCenter = 10.61250MHz (FM) / 10.690MHz ; 450KHz (AM)
recommended
-
-
-
-
-
-
0
1
0
1
1
fCenter = 10.67500MHz (FM) / 10.700MHz ; 460KHz (AM)
-
-
-
-
-
-
0
1
1
1
1
fCenter = 10.70000MHz (FM) / 10.704MHz ; 464KHz (AM)
recommended
-
-
-
-
-
-
1
1
1
1
1
fCenter = 10.80000MHz (FM) / 10.720MHz ;480KHz (AM)
0
0
0
Not valid
0
0
1
Not valid
47/76
Software specification
Table 18.
TDA7540N
Addr 6 IF counter control 2 (continued)
MSB
LSB
Function
d7
d6
d5
0
1
0
Not valid
0
1
1
Δf = 6.25kHz (FM)1kHz (AM) not recommended
1
0
0
Δf = 12.5kHz (FM) 2kHz (AM) not recommended
1
0
1
Δf = 25kHz (FM) 4kHz (AM)
1
1
0
Δf = 50kHz (FM) 8kHz (AM)
1
1
1
Δf = 100kHz (FM)16kHz (AM)
Table 19.
d4
d3
d2
d1
d0
Addr 7 AM control
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
0
Normal AGC time constant
1
Short time constant for AM seek stop
0
Multipath information available FM at PIN 24
1
AM stereo output available at PIN 24
0
0
Prescaler ratio 10
0
1
Prescaler ratio 8
1
0
Prescaler ratio 6
1
1
Prescaler ratio 4
0
0
Disable additional TV1, 2 offset
0
1
Enable additional TV1 offset +3.175V (for weather band)
1
0
Enable additional TV2 offset +3.175V (for weather band)
1
1
Enable additional TV1, 2 offset +3.175V (for weather band)
0
TV is tracking with PLL
1
TV is independing on PLL
0
Disable local mode
1
Enable local mode (PIN diode current = 0.5mA)
Table 20.
Addr 8 quality ISS filter
MSB
LSB
Function
d7
48/76
d6
d5
d4
d3
d2
d1
d0
0
ISS filter control “ON” recommended
1
ISS filter control “OFF”
0
Switch ISS filter “OFF”
1
Switch ISS filter “ON”
TDA7540N
Table 20.
Software specification
Addr 8 quality ISS filter (continued)
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
0
Switch “OFF” ISS filter 120kHz
1
Switch “ON” ISS filter 80kHz
0
Switch “OFF” ISS filter 30KHz for weatherband
1
Switch “ON” ISS filter 30KHz for weatherband
0
0
0
discharge current1µA, charge current mid 74µA
narrow124µA
0
0
1
discharge current3µA, charge current mid 72µA
narrow122µA
0
1
0
discharge current5µA, charge current mid 70µA
narrow120µA
0
1
1
discharge current7µA, charge current mid 68µA
narrow118µA
-
-
-
-
1
1
1
discharge current15µA,charge current mid 60µA
narrow110µA
Table 21.
Addr 9 quality detection adjacent channel
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
0
dc-coupling deviation detector (has to be 0 in AM mode)
1
ac-coupling deviation detector (recommended mode)
0
AC highpass frequency 100kHz
1
AC bandpass frequency 100kHz
0
AC gain 32dB
1
AC gain 38dB
0
0
0
AC wide band threshold 0.25V
0
0
1
AC wide band threshold 0.35V
0
1
0
AC wide band threshold 0.45V
-
-
-
-
1
1
1
AC wide band threshold 0.95V
0
0
AC narrow band threshold 0.0V
0
1
AC narrow band threshold 0.1V
1
0
AC narrow band threshold 0.2V
1
1
AC narrow band threshold 0.3V
49/76
Software specification
Table 22.
TDA7540N
Addr 10 quality detection multipath
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
0
Multipath control “ON”
1
Multipath control “OFF”
0
MP bandpass frequency 19KHz if MPION=1, NBSMP=1,
MPPC=1, than has to be 0
1
MP bandpass frequency 31KHz
0
MP gain 12dB
1
MP gain 23dB
0
0
MP threshold 0.50V
0
1
MP threshold 0.75V
1
0
MP threshold 1.00V
1
1
MP threshold 1.25V
0
0
Application mode 1
0
1
Application mode 2
0
Multipath eliminates ac
1
Multipath eliminates ac and ac+
Table 23.
Addr 11 quality deviation detection
MSB
LSB
Function
d7
50/76
d6
d5
d4
d3
d2
d1
d0
0
0
0
charge current 39µA, discharge current 1µA
0
0
1
charge current 38µA, discharge current 2µA
0
1
0
charge current 37µA, discharge current 3µA
0
1
1
charge current 36µA, discharge current 4µA
-
-
-
-
1
1
1
charge current 32µA, discharge current 8µA
0
0
DEV threshold for ISS narrow/wide 30kHz
0
1
DEV threshold for ISS narrow/wide 45kHz
1
0
DEV threshold for ISS narrow/wide 60kHz
1
1
DEV threshold for ISS narrow/wide 75kHz
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
TDA7540N
Table 23.
Software specification
Addr 11 quality deviation detection
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
0
Disable ISS filter to fixed bandwith (ISS80) in automatic
control
1
Enable ISS filter to fixed bandwith (ISS80) in automatic
control
Table 24.
Addr 12 softmute control 1
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
0
0
0
Startpoint mute 0 in application about 3dBµV antenna level
0
0
1
Startpoint mute 1 in application about 4dBµV antenna level
-
-
-
-
1
1
1
Startpoint mute 7 in application about 10dBµV antenna level
0
0
0
0
Mute depth 0 in application 18dB
0
0
0
1
Mute depth 1 in application 20dB
0
0
1
0
Mute depth 2 in application 22dB
0
0
1
1
Mute depth 3 in application 24dB
-
-
-
-
- (logarithmically behaviour)
1
1
1
1
Mute depth 15 in application 36dB
0
FM mute disable, (has to be 0 in AM mode)
1
FM mute enable
Table 25.
Addr 13 softmute control 2
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
0
Disable mute threshold for ISS filter “ON”
1
Enable mute threshold for ISS filter “ON”
0
0
AC mute depth 10dB
0
1
AC mute depth 8dB
1
0
AC mute depth 6dB
1
1
AC mute depth 4dB
0
0
0
0
AC mute threshold 60mV
0
0
0
1
AC mute threshold 80mV
0
0
1
0
AC mute threshold 100mV
-
-
-
-
-
0
1
1
1
AC mute threshold 340mV
51/76
Software specification
Table 25.
TDA7540N
Addr 13 softmute control 2
MSB
LSB
Function
d7
d6
d5
d4
d3
1
1
1
1
d2
d1
d0
AC mute “OFF”
0
AC mute filter 110KHz
1
AC mute filter 100KHz
Table 26.
Addr 14 VCODIV/PLLREF
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
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
1
0
0
PLL reference frequency 50KHz
1
0
1
PLL reference frequency 25KHz
1
1
0
PLL reference frequency 10KHz
1
1
1
PLL reference frequency 9KHz
0
0
0
PLL reference frequency 2KHz
0
Select FM mode
1
Select AM mode
0
Select PLL low pass filter FM
1
Select PLL low pass filter AM
Table 27.
Addr 15 FM AGC
MSB
LSB
Function
d7
52/76
d6
d5
d4
d3
d2
d1
d0
0
0
RFAGC threshold V9-11TH= 85(77 ANT)dBµV
0
1
RFAGC threshold V9-11TH= 90(82 ANT)dBµV
1
0
RFAGC threshold V9-11TH= 94(86 ANT)dBµV
1
1
RFAGC threshold V9-11TH= 96(88 ANT)dBµV
0
0
IFAGC threshold V77TH= 86(60 ANT)dBµV
0
1
IFAGC threshold V77TH= 92(66 ANT)dBµV
1
0
IFAGC threshold V77TH= 96(70 ANT)dBµV
1
1
IFAGC threshold V77TH= 98(72 ANT)dBµV
TDA7540N
Table 27.
Software specification
Addr 15 FM AGC
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
0
0
0
KAGC threshold 80dBµV
0
0
1
KAGC threshold 82dBµV
0
1
0
KAGC threshold 84dBµV
0
1
1
KAGC threshold 86dBµV
1
0
0
KAGC threshold 88dBµV
1
0
1
KAGC threshold 90dBµV
1
1
0
KAGC threshold 92dBµV
1
1
1
Keying AGC “OFF”
0
RF KAGC“0FF”
1
RF KAGC“0N”
Table 28.
Addr 16 AM AGC
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
0
0
0
0
not valid
0
0
0
1
not valid
0
0
1
0
WAGC V4TH= 97dBµ V71TH= 96.5dBµ
0
0
1
1
WAGC V4TH= 98.5dBµ V71TH= 98.5dBµ
0
1
0
0
WAGC V4TH= 100dBµ V71TH= 100dBµ
0
1
0
1
WAGC V4TH= 101.5dBµ V71TH= 101dBµ
0
1
1
0
WAGC V4TH= 102.5dBµ V71TH= 102.5dBµ
0
1
1
1
WAGC V4TH= 103.5dBµ V71TH= 103.5dBµ
1
0
0
0
WAGC V4TH= 104.5dBµ V71TH= 104dBµ
1
0
0
1
WAGC V4TH= 105dBµ V71TH= 105dBµ
1
0
1
0
WAGC V4TH= 106dBµ V71TH= 105.5dBµ
1
0
1
1
WAGC V4TH= 106.5dBµ V71TH= 106.5dBµ
1
1
0
0
WAGC V4TH= 107dBµ V71TH= 107dBµ
1
1
0
1
WAGC V4TH= 108dBµ V71TH= 107.5dBµ
1
1
1
0
WAGC V4TH= 108.5dBµ V71TH= 108dBµ
1
1
1
1
WAGC V4TH= 109dBµ V71TH= 108.5dBµ
0
0
0
0
DAGC V71TH= 74dBµ
0
0
0
1
DAGC V71TH= 77dBµ
0
0
1
0
DAGC V71TH= 79dBµ
0
0
1
1
DAGC V71TH= 80.5dBµ
53/76
Software specification
Table 28.
TDA7540N
Addr 16 AM AGC (continued)
MSB
LSB
Function
d7
d6
d5
d4
0
1
0
0
DAGC V71TH= 82dBµ
0
1
0
1
DAGC V71TH= 83.5dBµ
0
1
1
0
DAGC V71TH= 85dBµ
0
1
1
1
DAGC V71TH= 86.5dBµ
1
0
0
0
DAGC V71TH= 88dBµ
1
0
0
1
DAGC V71TH= 89dBµ
1
0
1
0
DAGC V71TH= 90dBµ
1
0
1
1
DAGC V71TH= 91dBµ
1
1
0
0
DAGC V71TH= 92dBµ
1
1
0
1
DAGC V71TH= 93dBµ
1
1
1
0
DAGC V71TH= 94dBµ
1
1
1
1
DAGC V71TH= 96dBµ
Table 29.
d3
d2
d1
d0
Addr 17 FM demodulator fine adjust
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
0
0
0
0
0
0
0mV
0
0
0
0
0
1
+8.5mV
0
0
0
0
1
0
+17mV
-
-
-
-
-
-
-
0
1
1
1
1
1
+263.5mV
1
0
0
0
0
0
0mV
1
0
0
0
0
1
-8.5mV
1
0
0
0
1
0
-17mV
-
-
-
-
-
-
-
1
1
1
1
1
1
-263.5mV
0
0
Spike cancelation ”OFF”
0
1
Threshold for spike cancelation 750mV
1
0
Threshold for spike cancelation 270mV
1
1
Threshold for spike cancelation 520mV recommended
54/76
TDA7540N
Table 30.
Software specification
Addr 18 S-meter slider
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
0
0
0
0
S meter slider offset SL=0dB
0
0
0
1
S meter offset SL=1dB
0
0
1
0
S meter offset SL=2dB
-
-
-
-
-
1
1
1
1
S meter offset SL=15dB
0
S meter offset -SL
1
S meter offset +SL
0
S Meter slope 1V/decade
1
S meter slope 1.5V/decade
0
Overdeviation correction current max=45µA
1
Overdeviation correction current max=90µA
0
Overdeviation correction “OFF”
1
Overdeviation correction “ON”
Table 31.
Addr 20 Tank Adjust
Addr 19 IF GAIN/XTAL adjust
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
0
Xtal amplitude limitation disable
1
Xtal amplitude limitation enable
0
0
IF1 gain1 9dB
0
1
IF1 gain1 12dB
1
0
IF1 gain1 15dB
1
1
IF1 gain1 18dB
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
1
CLoad 23.25pF
55/76
Software specification
Table 32.
TDA7540N
Tank adjust
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
0
0
0
0
450kHz 0pF
0
0
0
1
450kHz 1.6pF
0
0
1
0
450kHz 3.2pF
0
0
1
1
450kHz 4.8pF
-
-
-
-
-
1
1
1
1
450kHz 24pF
0
0
0
0
10.7MHz 0pF
0
0
0
1
10.7MHz 0.55pF
0
0
1
0
10.7MHz 1.1pF
0
0
1
1
10.7MHz 1.65pF
-
-
-
-
-
1
1
1
1
10.7MHz 8.25pF
Table 33.
Addr 21 I/Q FM mixer1 adjust
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
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
1
+8degree
0
0
Softmute reference offset OFF
0
1
Softmute reference offset -50mV
1
0
Softmute reference offset -100mV
1
1
Softmute reference offset -150mV
56/76
TDA7540N
Table 34.
Software specification
Addr 22 AM IF noise blanker
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
0
0
0
0
Not valid
0
0
0
1
AINBT 12.5mV
0
0
1
0
AINBT 25mV
-
-
-
-
-
1
1
1
1
AINBT 187.5mV
0
0
AINBD “ON”
0
1
AINBD 4.0V
1
0
AINBD 3.2V
1
1
AINBD “OFF”
0
0
AINT 8µs
0
1
AINT 11µs
1
0
AINT 14µs
1
1
AINT 17µs
Table 35.
Addr 23 switch control
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
0
S1 LOW output voltage
1
S1 HIGH output voltage
0
S1 emitter output available
1
S1 open collector output available
0
S2 LOW output voltage
1
S2 HIGH output voltage
0
S2 emitter output available
1
S2 open collector output available
0
0
0
0
SSTOP=IFC (IF counter status)
0
0
0
1
SSTOP= H if IFC=H&FSU>0.89V
0
0
1
0
SSTOP= H if IFC=H&FSU>1.16V
0
0
1
1
SSTOP= H if IFC=H&FSU>1.43V
-
-
-
-
1
1
1
1
SSTOP= H if IFC=H&FSU>4.67V
57/76
Software specification
Table 36.
TDA7540N
Addr 24 stereodecoder 1
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
1
only for testing (has to be set to 1)
0
not valid (only for testing)
1
Audio AM noise blanker fix threshold enable
1
only for testing (has to be set to 1)
0
Audio inverter OFF
1
Audio inverter ON
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
0
Stereodecoder VCO adjust minus
1
Stereodecoder no VCO adjust recommended
0
Stereodecoder VCO adjust plus
1
Stereodecoder no VCO adjustrecommended
Table 37.
Addr 25 stereodecoder 2
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
0
Stereo decoder mute disable
1
Stereo decoder mute enable
0
Stereo decoder “ON” if muted
1
Stereo decoder “OFF” if muted
0
Forced MONO, must be set in AM
1
MONO/STEREO switch automatically
0
Noise blanker peak charge current low
1
Noise blanker peak charge current high
0
Pilot threshold high
1
Pilot threshold low
0
Deemphasis 50µs
1
Deemphasis 75µs
0
0
Stereodecoder ingain = 3.75dB
0
1
Stereodecoder ingain = 2.5dB
1
0
Stereodecoder ingain = 1.25dB
1
1
Stereodecoder ingain = 0dB
58/76
TDA7540N
Table 38.
Software specification
Addr 26 stereodecoder 3
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
0
0
0
Audio noise blanker low threshold 280mV
0
0
1
Audio noise blanker low threshold 261mV
0
1
0
Audio noise blanker low threshold 242mV
0
1
1
Audio noise blanker low threshold 223mV
1
0
0
Audio noise blanker low threshold 204mV
1
0
1
Audio noise blanker low threshold 185mV
1
1
0
Audio noise blanker low threshold 166mV
1
1
1
Audio noise blanker low threshold 147mV
0
0
Audio noise blanker noise controlled threshold 1200mV
0
1
Audio noise blanker noise controlled threshold 950mV
1
0
Audio noise blanker noise controlled threshold 700mV
1
1
Audio noise blanker noise controlled threshold 450mV
0
Audio noise blanker OFF
1
Audio noise blanker ON
0
0
Deviation adjust 2.0V
0
1
Deviation adjust 1.5V
1
0
Deviation adjust 1.0V
1
1
Deviation detector off
Table 39.
Addr 27 stereodecoder 4
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
0
High Cut OFF
1
High Cut ON
0
0
max. High Cut 10dB
0
1
max. High Cut 5.5dB
1
0
max. High Cut 7.5dB
1
1
max. High Cut 8.5dB
0
0
Start level High Cut at 42% REF5V
0
1
Start level High Cut at 50% REF5V
1
0
Start level High Cut at 58% REF5V
1
1
Start level High Cut at 66% REF5V
0
0
Stop level High Cut at 11% VHCH
0
1
Stop level High Cut at 18.3% VHCH
59/76
Software specification
Table 39.
TDA7540N
Addr 27 stereodecoder 4 (continued)
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
1
0
Stop level High Cut at 25.7% VHCH
1
1
Stop level High Cut at 33% VHCH
0
Strong multipath influence on peak discharge OFF
1
Strong multipath influence on peak discharge ON (MPF = 0!!)
Table 40.
Addr 28 stereodecoder 5
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
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
0
0
Audio noise blanker field strength adjust 2.0V
0
1
Audio noise blanker field strength adjust 1.6V
1
0
Audio noise blanker field strength adjust 1.4V
1
1
Audio noise blanker field strength adjust OFF
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
0
Multipath influence on peak discharge OFF
1
Multipath influence on peak discharge ON (-1V/ms) (MPF = 0!!)
Table 41.
Addr 29 stereodecoder 6
MSB
LSB
Function
d7
60/76
d6
d5
d4
d3
d2
d1
d0
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
TDA7540N
Table 41.
Software specification
Addr 29 stereodecoder 6 (continued)
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
0
0
Multipath detector band pass gain =6dB
0
1
Multipath detector band pass gain =12dB
1
0
Multipath detector band pass gain =9dB
1
1
Multipath detector band pass gain =10.5dB
0
Multipath detector internal influence ON
1
Multipath detector internal influence OFF
0
Multipath detector charge current =0.8µA
1
Multipath detector charge current =0.4µA
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
Table 42.
Addr 30 stereodecoder 7
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
0
0
0
0
Roll-Off compensation not allowed
0
0
0
1
Roll-Off compensation 17.1%
0
0
1
0
Roll-Off compensation 15.2%
0
0
1
1
Roll-Off compensation 13.3%
0
1
0
0
Roll-Off compensation 11.4%
0
1
0
1
Roll-Off compensation 9.6%
0
1
1
0
Roll-Off compensation 7.8% recommended
0
1
1
1
Roll-Off compensation 6.0%
1
0
0
0
Roll-Off compensation not allowed
1
0
0
1
Roll-Off compensation 4.7%
1
0
1
0
Roll-Off compensation 2.9%
1
0
1
1
Roll-Off compensation 1.3%
1
1
0
0
Roll-Off compensation -0.2%
1
1
0
1
Roll-Off compensation -1.8%
1
1
1
0
Roll-Off compensation -3.4%
1
1
1
1
Roll-Off compensation -5%
0
0
0
Level gain 0dB
0
0
1
Level gain 0.67dB
61/76
Software specification
Table 42.
TDA7540N
Addr 30 stereodecoder 7 (continued)
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
0
1
0
Level gain 1.34dB
-
-
-
-
1
1
1
Level gain 4.7dB
0
AM audio filter “OFF”
1
AM audio filter “ON” (has to be set if AMNB is used !!)
Table 43.
Addr 31 stereodecoder 8
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
0
0
Quality noise gain =6dB
0
1
Quality noise gain =9dB
1
0
Quality noise gain =12dB
1
1
Quality noise gain =15dB
0
Enable AFS PIN
1
Disable AFS PIN
0
AFS influence on stereodecoder mute
1
No AFS influence on stereodecoder mute
0
PD hold activation if AFS<Vth1
1
PD hold activation if AFS<Vth2
0/1
not valid
0/1
not valid
0
AM audio delay for noise blanking “OFF”
1
AM audio delay for noise blanking “ON”(has to be set if
AMNB is used !!)
Table 44.
Addr 32 stereodecoder 9
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
0
Deemphasis shift (25/37.5µs)
1
Deemphasis no shift (50/75µs)
0
0
0
0
0
AM corner frequency = 3.18kHz
0
0
0
0
1
AM corner frequency = 3.10kHz
0
0
0
1
0
AM corner frequency = 3.02kHz
-
-
-
-
-
1
1
1
0
1
AM corner frequency = 1.12kHz
1
1
1
1
1
AM corner frequency = 1.06kHz
62/76
TDA7540N
Table 45.
Software specification
Addr 33 test tuner control 1
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
x
x
x
x
x
x
x
x
Table 46.
Only for testing ( have to be set to 0)
Addr 34 test tuner control 2
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
x
x
x
x
x
x
x
x
Table 47.
Only for testing ( have to be set to 0)
Addr 35 test tuner control 3
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
x
x
x
x
x
x
x
x
Table 48.
Only for testing ( have to be set to 0)
Addr 36 test tuner control 4
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
x
x
x
x
x
x
x
x
Table 49.
Only for testing ( have to be set to 0)
Addr 37 test tuner control 5
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
x
x
x
x
x
x
x
x
Table 50.
Only for testing ( have to be set to 0)
Addr 38 test stereodecoder control
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
x
x
x
x
x
x
x
0
Table 51.
Only for testing ( have to be set to 1)
Addr39 test FM demodulator spike blanker and stereo decoder
MSB
LSB
Function
d7
d6
d5
d4
d3
d2
d1
d0
x
x
x
x
x
x
x
0
Only for testing ( have to be set to 1)
63/76
Appendix
TDA7540N
6
Appendix
Figure 8.
Block diagram I/Q mixer
Figure 9.
Block diagram VCO
64/76
TDA7540N
Appendix
Figure 10. Block diagram keying AGC
Figure 11. Block diagram ISS function
65/76
Appendix
TDA7540N
Block diagram quality detection principle (without overdeviation correction)
Table 52.
Block diagram quality detection principle
Signal
Low
High
ac
No adjacent channel
Adjacent channel present
ac+
No strong adjacent channel
Adjacent channel higher as ac
sm
Fieldstrength higher as softmute threshold
Fieldstrength lower as softmute 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)
Table 53.
Functional mode quality detection
Input signals
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
1
0
1
0
0
1
1
narrow
1
1
narrow
1
1
1
0
0
1
1
narrow
1
1
narrow
1
0
1
1
0
1
0
mid
1
0
mid
1
1
1
1
0
1
0
mid
1
1
narrow
1
0
1
1
1
1
0
mid
1
0
mid
1
1
1
1
1
1
0
mid
1
1
narrow
66/76
TDA7540N
Appendix
Figure 12. Block diagram AM part
67/76
Appendix
Figure 13. Block diagram AM IF noise blanker
Figure 14. Block diagram stereodecoder
68/76
TDA7540N
TDA7540N
Appendix
Figure 15. Block diagram audio noise blanker
Figure 16. Block diagram multipath detection
69/76
Appendix
Figure 17. Block diagram AFS function
70/76
TDA7540N
TDA7540N
7
Part list
Part list
Table 54.
Part list (application- and measurment circuit)
Item
Description
F1
TOKO 5KM 396INS-A543EK
F2
TOKO MC152 E558HNA-100092
F3
TOKO 7PSG P826RC-5134N
F4
TOKO PGL 5PGLC-5103N
L1
TOKO FSLM 2520-150 15uH
L2,L4
TOKO FSLM 2520-680 68uH
L3
SIEMENS SIMID03 B82432 1mH
L5
TOKO LLQ 2012-220
L6
TOKO LLQ 2012-680
CF1,CF2
muRata SFE10.7MS3A10-A 180KHz
CF3
muRata SFE10.7MJA10-A 150KHz
CF4
muRata SFPS 450H
D1
TOSHIBA 1SV172
D2,D3
TOKO KP2311E
D4
TOKO KV1410
D5
PHILIPS BB156
Q1
TOSHIBA HN3G01J
71/76
Application circuit
8
Application circuit
Figure 18. Application circuit
72/76
TDA7540N
TDA7540N
9
Application notes
Application notes
Following items are important to get highest performance of TDA7540N in application:
1.
In order to avoid leakage current from PLL loop filter input to ground a guardring is
recommended around loop filter PIN’s with PLL reference (VREF2) voltage potential.
2.
Distance between Xtal and VCO input PIN 18 should be far as possible and Xtal
package should get a shield versus ground.
3.
Blocking of VCO supply should be near at PIN 20 and PIN 21.
4.
Blocking of VCC2 supply should be near at PIN 64 and PIN 61.
5.
Wire lenght to FM mixer1-input and -output should be symetrically and short.
6.
FM demodulator capacitance at PIN 56 should be sense connected as short as
possible versus demodulator ground at PIN 57.
7.
Wire lenght from AM mixer tank output to 9KHz ceramic filter input has to be short as
possible.
8.
To minimize “AM TWEET” the AM demodulator capacitor should be connected versus
GNDVCC1 at PIN 41 and FSU output at PIN 22 should be filtered with capacitor of
about 2,2nF versus GNDVCC2.
73/76
Package information
10
TDA7540N
Package information
In order to meet environmental requirements, ST offers these devices in ECOPACK®
packages. These packages have a lead-free second level interconnect. 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 19. LQFP80 (14x14x1.40mm) mechanical data and package dimensions
mm
inch
DIM.
MIN.
TYP.
A
MAX.
MIN.
TYP.
MAX.
1.600
0.0630
0.150 0.0020
0.0059
A1
0.050
A2
1.350
1.400
1.450 0.0531 0.0551 0.0571
b
0.220
0.320
0.380 0.0087 0.0126 0.0150
c
0.090
0.200 0.0035
0.0079
D
15.800 16.000 16.200 0.6220 0.6299 0.6378
D1
13.800 14.000 14.200 0.5433 0.5512 0.5591
D3
12.350
0.4862
E
15.800 16.000 16.200 0.6220 0.6299 0.6378
E1
13.800 14.000 14.200 0.5433 0.5512 0.5591
E3
12.350
e
L
L1
k
ccc
0.4862
0.650
0.450
0.600
OUTLINE AND
MECHANICAL DATA
0.0256
0.750 0.0177 0.0236 0.0295
1.000
0.0394
LQFP80 (14x14x1.40mm)
Low profile Quad Flat Package
0˚ (min.); 3.5˚ (typ,); 7˚ (max.)
0.100
0.0039
0062342 D
74/76
TDA7540N
11
Revision history
Revision history
Table 55.
Document revision history
Date
Revision
12-Nov-2007
1
Changes
Initial release.
75/76
TDA7540N
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