Philips TDA3866 Datasheet

INTEGRATED CIRCUITS

DATA SH EET

TDA3866

Quasi-split sound processor for all
standards

Preliminary specification
File under Integrated Circuits, IC02

January 1992

Philips Semiconductors Preliminary specification

Quasi-split sound processor for all standards TDA3866

FEATURES

• Quasi-split sound processor for all standards e. g. B/G
(FM sound) and L (AM sound)

• AF2 signal automatically muted (at B/G) by the input
signal level

• AM signal processing for L standard and switching over
the audio signal

• Stereo-matrix correction

• Layout-compatible with TDA3858 (32 pins) and

TDA3857 (20 pins)

• AM output level typically 500 mV at m = 0.54 (+2.5 dB in
comparison to TDA3856)

GENERAL DESCRIPTION

Separate symmetrical IF inputs for FM or AM sound.
Gain controlled wideband IF amplifier, input select switch.

AGC generation due to peak sync for FM or mean signal
level for AM. Reference amplifier for the regeneration of
the vision carrier. Optimized limiting amplifier for AM
suppression in the regenerated vision carrier signal and
90° phase shifter.

Intercarrier mixer for FM sound, output with low-pass filter.
Separate signal processing for 5.5 and 5.74 MHz

intercarriers.
Wide supply voltage range, only 300 mW power

dissipation at 5 V.

QUICK REFERENCE DATA

SYMBOL PARAMETER MIN. TYP. MAX. UNIT

V

P

I

P

V

iIF

V

o

supply voltage (pin 21) 4.5 5 8.8 V
supply current − 60 72 mA
IF input sensitivity (−3 dB) − 70 100 µV
audio output signal for FM standard B/G (RMS value) − 1 − V
audio output signal for AM standard L (RMS value) − 0.5 − V

THD total harmonic distortion

for FM − 0.5 − %
for AM − 1 − %

S/N (W) weighted signal-to-noise ratio

for FM − 68 − dB
for AM − 56 − dB

ORDERING AND PACKAGE INFORMATION

EXTENDED TYPE

NUMBER

PINS PIN POSITION MATERIAL CODE

PACKAGE

TDA3866 24 shrink DIL plastic SOT234

Note

1. SOT234-1; 1997 January 8.

January 1992 2

(1)

Philips Semiconductors Preliminary specification

Quasi-split sound processor for all standards TDA3866

Fig.1 Block diagram (B/G and L).

January 1992 3

Philips Semiconductors Preliminary specification

Quasi-split sound processor for all standards TDA3866

PINNING

SYMBOL PIN DESCRIPTION

AMIF1 1 AM IF difference input 1 for L standard (32.4 MHz)
AMIF2 2 AM IF difference input 2 for L standard
C
C

AGC
AM

3 charge capacitor for AGC (FM and AM)

4 charge capacitor for AM AGC
MODE 5 3-state input for standard select
FM2R1 6 reference circuit for FM2 (5.74 MHz)
FM2R2 7 reference circuit for FM2 (5,74 MHz)
AF2 8 AF2 output (AF out of 5.74 MHz)
AF1 9 AF1 output (AF out of 5.5 MHz or AM)
FM1R1 10 reference circuit for FM1 (5.5 MHz)
FM1R2 11 reference circuit for FM1 (5.5 MHz)
VC-R1 12 reference circuit for the vision carrier (38.9 MHz)
VC-R2 13 reference circuit for the vision carrier (38.9 MHz)
C

AFAM

14 DC-decoupling capacitor for AM demodulator (AF-AM)
FM1I 15 intercarrier input for FM1 (5.5 MHz)
C

AF1

16 DC-decoupling capacitor for FM1 demodulator (AF1)
ICO 17 intercarrier output signal (5.5/5.74 MHz)
C

AF2

18 DC-decoupling capacitor for FM2 demodulator (AF2)
FM2I 19 intercarrier input for FM2 (5.74 MHz)
GND 20 ground (0 V)
V

P

C

ref

21 +5 ... +8 V supply voltage

22 charge capacitor for reference voltage
FMIF1 23 IF difference input 1 for B/G standard (38.9 MHz)
FMIF2 24 IF difference input 2 for B/G standard (38.9 MHz)

PIN CONFIGURATION

Fig.2 Pin configuration.

January 1992 4

Philips Semiconductors Preliminary specification

Quasi-split sound processor for all standards TDA3866

FUNCTIONAL DESCRIPTION

The quasi-split sound processor is for
all standards. Dependent on the
voltage on pin 5 either FM mode
(B/G) or AM mode (L) is selected.

B/G standard (FM mode):
Pins 23 and 24 are active, AGC
detector uses peak sync level. Sound
carrier SC1 (5.5 MHz) provides AF1,
sound carrier SC2 (5.74 MHz)
provides AF2. With no sound carrier
SC2 on pin 19, AF2 output is muted
(in mid-position of the standard select
switch FM mode without muting of
AF2 is selected).

The mute circuit prevents false signal
recognition in the stereo decoder at
high IF signal levels when no second
sound carrier exists (mono) and an
AF signal is present in the
identification signal frequency range.

With 1 mV on pin 19, under
measurement conditions, AF2 is
switched on (see limiting amplifier).
Weak input signals at pins 23 and 24
generate noise on pin 19, which is
present in the intercarrier signal and
passes through the 5.74 MHz filter.
Noise on pin 19 inhibits muting. No
misinterpretation due to white noise
occurs in the stereo decoder; when
non-correlated noise masks the
identification signal frequencies,
which may be present in sustained

tone signals. The stereo decoder
remains switched to mono.

The series capacitor C
resonant circuit provides a notch at
the sound carrier frequency in order
to provide more attenuation for the
sound carrier in the vision carrier
reference channel. The ratio of
parallel/series capacitor depends on
the ratio of VC/SC frequency and has
to be adapted to other TV
transmission standards if necessary,
according to the formula
CS=CP (fVC/fSC)2− CP.

The result is an improved “intercarrier
buzz” (up to 10 dB improvement in
sound channel 2 with 250 kHz video
modulation for B/G stereo) or
suppression of 350 kHz video
modulated beat frequency in the
digitally-modulated NICAM
subcarrier.
The picture carrier for quadrature
demodulation in the intercarrier mixer
is not exactly 90 degrees due to the
shift variation in the integrated phase
shift network. The tuning of the LC
reference circuit to provide optimal
video suppression at the intercarrier
output is not the same as that to
provide optimal intercarrier buzz
suppression. In order to optimize the
AF signal performance, a fine tuning
for the optimal S/N at the sound
channel 2 (from 5.74 MHz) may be
performed with a 250 kHz square
wave video modulation.

in 38.9 MHz

s

Measurements at the demodulators:
For all signal-to-noise measurements
the generator must meet the following
specifications;
phase modulation errors < 0.5 degree
for B/W-jumps intercarrier
signal-to-noise ratio as measured
with “TV-demodulator AMF2”
(weighted S/N) must be > 60 dB at
6 kHz sine wave modulation of the
B/W-signal.
Signal-to-noise ratios are measured
with ∆f=±50 kHz deviation and
f

= 1 kHz; with a deviation

mod

of ±27 kHz the S/N ratio is
deteriorated by 5.3 dB.

L standard (AM mode): Pins 1 and 2
are active, AGC detector uses mean
signal level. The audio signal from the
AM demodulator is output on AF1,
with AF2 output muted.

January 1992 5