U2860B-B
Preliminary Information
TELEFUNKEN Semiconductors
Rev. A1, 17-Jun-96
1 (11)
Dual-Channel FM Sound Demodulator for TV Systems
Description
The U2860B is a dual-channel FM sound demodulator
realized with TEMIC's advanced bipolar process. All TV
FM standards, from 4.5 up to 6.5 MHz (standard M, B/G,
I, D/K) can be processed with high performance. The
circuit is alignment-free and has a minimum number of
external components. With 5 V supply voltage, the
U2860B is suitable for TV, VCR and multimedia
applications.
Features
D Two alignment-free PLL
FM
demodulators,
automatic lock in on the received sound carrier
frequency
D Mono and dual channel application
D Sound IF inputs provided for ceramic filters
D Automatic mute for 2nd sound channel (squelch)
D Mute function for both sound channels
D 5 V supply voltage, low power consumption
D Few external components
Package: DIP14, SO14
Loop
filter 1
VCO 1
Mute
1
3
4
13
11
12
Supply
8
7
94 8139 e
C
stab
VCO
offset
10
VCO offset
Loop
filter 2
VCO 1
V
S
Squelch
Squelch (second carrier)
14
Squelch
V
in1
V
in2
Mute
V
AF1
V
AF2
6
9
R
ref
(optional)
Figure 1. Block diagram
U2860B-B
TELEFUNKEN Semiconductors
Rev. A1, 17-Jun-96
Preliminary Information
2 (11)
Circuit Description
The U2860B includes two identical sound IF channels.
Each consists of a limiter amplifier, PLL FM demodulator
and AF amplifier. Additionally, this circuit contains a
squelch function, mute switch and internal voltage
regulation.
Limiter Amplifiers
The intercarrier signals are fed through external ceramic
bandpass filters to a 7-stage limiter amplifier. This
guarantees high input sensitivity and excellent
AM suppression.
PLL FM Demodulators
The alignment-free "Phase Locked Loop" (PLL) demo-
dulator covers a wide frequency range of 4.5 MHz up to
6.5 MHz with low noise performance. The linear voltage
to frequency characteristic results in low harmonic
distortion. The free-running frequency of the internal
VCO circuit is about 5.5 MHz. For this frequency, the
input sensitivity and VCO locking is optimal. An addi-
tional external resistor at Pin 10 allows a frequency shift
of
1 MHz via an internal offset current. With this option,
it is possible to shift the optimum conditions to the upper
frequency (6.5 MHz) or to the lower frequency
(4.5 MHz). The offset current acts simultaneously on
both VCO circuits. If no resistor is connected, the offset
current is disabled.
Audio Amplifiers
The demodulated signals are amplified to 500 mVrms
with low output impedance at the audio outputs (Pin 6 and
Pin 7). AC decoupling at Pin 8 and Pin 9 of the audio am-
plifiers leads to high common mode rejection.
Squelch Function
For channel 2 the audio output amplifier and VCO2 is
muted automatically (squelch) when the second sound
carrier is not present. This avoids a wrong identification
for stereo and dual sound in the stereo decoder. Therefore,
with mono sound, there is no output signal at Pin 6. The
automatic squelch function can be disabled by switching
Pin 4 to ground.
Mute Switch
Simultaneously muting of both circuits is possible by
switching Pin 3 to ground.
Internal Voltage Stabilizer
The internal bandgap reference ensures constant
performance independent of supply voltage and
temperature.
Ordering Information
Extended Type Number
Package
Remarks
U2860B-B
DIP14
U2860B-BFP
SO14
taped
U2860B-B
Preliminary Information
TELEFUNKEN Semiconductors
Rev. A1, 17-Jun-96
3 (11)
Pin Description
14
13
12
11
10
9
8
1
2
3
4
5
6
7
94 8679
V
in1
NC
V
mute
V
sque
V
AF2
V
AF1
GND
V
in2
V
S
C
stab
R
ref
C
9
C
8
U2860B
NC
Figure 2. Connection diagram
Pin
Symbol
Function
1
V
in1
Intercarrier input of sound
channel 1 (5.5 MHz)
2
NC
Not connected
3
V
mute
Mute for sound channel 1+2
"on/off"
4
V
sque
Automatic mute for 2nd sound
channel (squelch) "on/off"
5
NC
Not connected
6
V
AF2
Audio output AF2 of sound
channel 2
7
V
AF1
Audio output AF1 of sound
channel 1
8
C
8
Decoupling capacitor for sound
channel 1
9
C
9
Decoupling capacitor for sound
channel 2
10
R
ref
VCO offset of the free-running
frequency
11
C
stab
Internal supply voltage
stabilization
12
GND
Ground
13
V
S
Supply voltage
14
V
in2
Intercarrier input of sound
channel 2 (5.74 MHz)
Maximum Ratings
Reference point Pin 12, unless otherwise specified
Parameters
Symbol
Value
Unit
Supply voltage
Pin 13
V
S
9.0
V
Supply current
Pin 13
I
S
33
mA
Power dissipation
V
S
= +9 V
P
300
mW
Output currents
Pin 6, 7
I
out
1.5
mA
External voltages
Pin 1, 14
Pin 3, 4
Pin 6, 7, 8, 9, 10, 11
V
ext
V
ext
V
ext
2.0
V
S
4.5 V
V
V
V
Junction temperature
T
j
+125
C
Storage temperature
T
stg
25 to +125
C
Electrostatic handling
*
) all pins
V
ESD
200
V
*
)
Machine model in accordance with ESD S5.2 standard
U2860B-B
TELEFUNKEN Semiconductors
Rev. A1, 17-Jun-96
Preliminary Information
4 (11)
Operating Range
Parameters
Symbol
Value
Unit
Supply voltage range
Pin 13
V
S
4.5 to 9.0
V
Ambient temperature
T
amb
0 to +85
C
Thermal Resistance
Parameters
Symbol
Value
Unit
Junction ambient when soldered to PCB
R
thJA
90
K/W
Electrical Characteristics
V
S
= 5 V, T
amb
= 25
_C, reference point Pin 12, unless otherwise specified
Parameters
Test Conditions / Pins
Symbol
Min.
Typ.
Max.
Unit
DC-supply
Pin 13
Supply voltage range
V
S
4.5
5.0
9.0
V
Supply current
I
S
27
33
mA
Intercarrier input 1
Pin 1
DC input voltage
V
DC
1.75
V
Input resistance
See note 1
R
in
680
750
W
Input limiting voltage
Input signal v
in
:
f = 5.5 MHz
output signal AF1:
v
AF1
3 dB
v
lim
150
mV
Intercarrier input 2
Pin 14
DC input voltage
V
DC
1.75
V
Input resistance
See note 1
R
in
680
750
W
Input limiting voltage
Input signal v
in
:
f = 5.74 MHz
output signal AF2:
v
AF2
3 dB
v
lim
150
mV
Input signal for automatic
second sound carrier "mute
off" (squelch)
Audio output AF2 active
v
in
> 0.7
1.0
< 1.5
mV
FM demodulators, internal VCO's
Pin 10
Free-running frequency
f
VCO
5.5
MHz
Oscillator drift
(free-running) as function
of temperature
T = 55
C
f
VCO
500
kHz
Oscillator shift
(free-running) as function
of supply voltage
4.5 V < V
S
< 5.5 V
f
VCO
200
kHz
Adjustment range of
free-running frequencies
By external resistor R
ref
at
Pin 10
f
adj
1
MHz
Adjustment resistance for
free-running frequencies
R
ref
15
22
30
k
W
U2860B-B
Preliminary Information
TELEFUNKEN Semiconductors
Rev. A1, 17-Jun-96
5 (11)
Unit
Max.
Typ.
Min.
Symbol
Test Conditions / Pins
Parameters
FM demodulators, internal VCO's
Pin 10
Steepness of free-running
frequency adjustment
Resistor R
ref
at Pin 10
S
200
kHz/k
W
Capture range of PLL's
f
cap
1.4
1.9
MHz
Holding range of PLL's
f
hold
2.0
3.0
MHz
Audio outputs, AF1 (Pin 7) and AF2 (Pin 6)
DC output voltage
V
DC
2.2
V
DC output current
I
DC
1.0
1.3
mA
Output resistance
See note 1
R
out
150
W
AC output peak current
i
AC
1.0
mA
AF output voltage,
RMS value
v
in
= 10 mV,
f = 5.5 MHz,
FM-dev. = 27 kHz,
f
mod
= 1 kHz
v
AF
500
mV
Difference between the
output signals
v
AF
1
dB
Total harmonic distortion
v
in
= 10 mV,
f = 5.5 MHz,
FM-dev. = 27 kHz,
f
mod
= 1 kHz
THD
0.1
0.5
%
AM suppression
v
in
= 10 mV,
f = 5.5 MHz,
f
mod
= 1 kHz,
reference signal:
FM-dev. = 50 kHz
test signal: m = 30%
a
AM
46
66
dB
Crosstalk attenuation
between the AF outputs
f = 50 Hz to 12.5 kHz
a
att
70
dB
Supply voltage ripple
rejection
V
RR
< 200 mV, f = 70 Hz
RR
24
dB
Mute switch
Pin 3
Control voltage - muteoff
- mute on
AF outputs active
AF outputs not active
V
mute
2.0
0
V
S
0.8
V
V
Control current
I
mute
150
mA
Squelch function
Pin 4
Control voltage for
automatic mute-2nd carrier
"off"
automatic mute-2nd carrier
"on"
V
sque
0
2.0
0.8
V
S
V
V
Control current
I
sque
150
mA
Notes
1.)
This parameter is given as an application information and not measured during final testing.
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