Data Sheet

TDA6170X

Semiconductor Group

6

21.7.99

7.3.1

Logic Allocation

7.3.2

IF-Muting

7.4

Converter Mixer

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.

7.5

IF Limiter with Demodulator

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.

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

1. Chip address (CAS) Pin 5 grounded

0

1

0

0

0

1

0

0

A

=H44

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