
Data Sheet
TDA6170X
Semiconductor Group
6
21.7.99
7.3.1
Logic Allocation
7.3.2
IF-Muting
7.4
In the converter mixer the sound subcarriers (frequency band approx. 5 to 9.9 MHz) contained in the base-
band of the received composite satellite signal are converted to an output frequency of 10.52 MHz and 10.7
MHz for example. The converter consists of a high-pass input filter followed by a double balanced mixer and a
low impedance output.
The signal of the on chip voltage controlled oscillator (VCO) is applied to the PLL input.
Converter Mixer
7.5
The two limiter amplifiers are implemented as balanced five stage, capacitively coupled differential amplifiers.
The three inputs are designed as high-pass inputs. The load resistors for the IF filters are connected to
ground.
The output signals of the limiter amplifiers are fed directly to the internal PLL FM demodulators.
The demodulated AF signals are fed to the input of a pre volume control part in front of the expander the de-
emphasis networks and audio switches.
IF Limiter with Demodulator
Byte
Data
Remarks
Address Byte
0
1
0
0
0
0
MA
R/W
A
Progr. Divider Byte 1
0
0
N11
N10
N9
N8
N7
N6
A
Progr. Divider Byte 2
0
0
N5
N4
N3
N2
N1
N0
A
Control Byte 1
1
5I
Z2
Z1
Z0
X
X
X
A
Control Byte 2
1
VL2
VL1
VL0
VR2
VR1
VR0
X
A
Control Byte 3
1
PVL2
PVL1
PVL0 PVR2 PVR1 PVR0
X
A
Address Byte 1
1
1. Chip address (CAS) Pin 5 grounded
0
1
0
0
0
1
0
0
A
=H44
Address Byte 2
2
2. Chip address (CAS) Pin 5 open
0
1
0
0
0
1
1
0
A
=H46
Control Bits
IF-Source
Function
Z2
Z1
Z0
IF1
IF2
IF3
0
0
0
on
on
off
expanders are working, audio = stereo
0
0
1
off
on
off
expanders are working, audio = mono
0
1
0
on
off
off
expanders are working, audio = mono
0
1
1
off
off
on
de-emphasis = 50
μ
; audio = mono
1
0
0
off
off
on
de-emphasis = 75
μ
; audio = mono
1
0
1
off
off
on
de-emphasis = J17; audio = mono
1
1
0
off
off
off
External audio
1
1
1
off
off
off
Mute