tda1072a.pdf
(
648 KB
)
Pobierz
199643192 UNPDF
INTEGRATED CIRCUITS
DATA SHEET
TDA1072A
AM receiver circuit
Product specification
File under Integrated Circuits, IC01
May 1984
Philips Semiconductors
Product specification
AM receiver circuit
TDA1072A
GENERAL DESCRIPTION
The TDA1072A integrated AM receiver circuit performs the active and part of the filtering functions of an AM radio
receiver. It is intended for use in mains-fed home receivers and car radios. The circuit can be used for oscillator
frequencies up to 50 MHz and can handle r.f. signals up to 500 mV. R.F. radiation and sensitivity to interference are
minimized by an almost symmetrical design. The voltage-controlled oscillator provides signals with extremely low
distortion and high spectral purity over the whole frequency range even when tuning with variable capacitance diodes.
If required, band switching diodes can easily be applied. Selectivity is obtained using a block filter before the i.f. amplifier.
Features
·
Inputs protected against damage by static discharge
·
Gain-controlled r.f. stage
·
Double balanced mixer
·
Separately buffered, voltage-controlled and temperature-compensated oscillator, designed for simple coils
·
Gain-controlled i.f. stage with wide a.g.c. range
·
Full-wave, balanced envelope detector
·
Internal generation of a.g.c. voltage with possibility of second-order filtering
·
Buffered field strength indicator driver with short-circuit protection
·
A.F. preamplifier with possibilities for simple a.f. filtering
·
Electronic standby switch.
QUICK REFERENCE DATA
Supply voltage range
V
P
7,5 to 18 V
Supply current range
I
P
15 to 30 mA
R.F. input voltage for S
+
N/N = 6 dB at m = 30%
V
i
typ.
1,5
m
V
R.F. input voltage for 3% total harmonic
distortion (THD) at m = 80%
V
i
typ.
500 mV
A.F. output voltage with V
i
= 2 mV;
f
i
= 1 MHz; m = 30% and f
m
= 400 Hz
V
o(af)
typ.
310 mV
A.G.C. range: change of V
i
for 1 dB change of V
o(af)
typ.
86 dB
Field strength indicator voltage at
V
i
= 500 mV; R
L(9)
= 2,7 k
W
V
IND
typ.
2,8 V
PACKAGE OUTLINE
16-lead DIL; plastic (SOT38); SOT38-1; 1996 August 09.
May 1984
2
Philips Semiconductors
Product specification
AM receiver circuit
TDA1072A
(1) Coil data: TOKO sample no. 7XNS-A7523DY; L1 : N1/N2 = 12/32; Q
o
= 65; Q
B
= 57.
Filter data: Z
F
= 700
W
at R
3-4
= 3 k
W
; Z
I
= 4,8 k
W
.
Fig.1 Block diagram and test circuit (connections shown in broken lines are not part of the test circuit).
May 1984
3
Philips Semiconductors
Product specification
AM receiver circuit
TDA1072A
FUNCTIONAL DESCRIPTION
Gain-controlled r.f. stage and mixer
The differential amplifier in the r.f. stage employs an a.g.c. negative feedback network to provide a wide dynamic range.
Very good cross-modulation behaviour is achieved by a.g.c. delays at the various signal stages. Large signals are
handled with low distortion and the S/N ratio of small signals is improved. Low noise working is achieved in the differential
amplifier by using transistors with low base resistance.
A double balanced mixer provides the i.f. output signal to pin 1.
Oscillator
The differential amplifier oscillator is temperature compensated and is suitable for simple coil connection. The oscillator
is voltage-controlled and has little distortion or spurious radiation. It is specially suitable for electronic tuning using
variable capacitance diodes. Band switching diodes can easily be applied using the stabilized voltage V
11-16
. An extra
buffered oscillator output (pin 10) is available for driving a synthesizer. If this is not needed, resistor R
L(10)
can be omitted.
Gain-controlled i.f. amplifier
This amplifier comprises two cascaded, variable-gain differential amplifier stages coupled by a band-pass filter. Both
stages are gain-controlled by the a.g.c. negative feedback network.
Detector
The full-wave, balanced envelope detector has very low distortion over a wide dynamic range. Residual i.f. carrier is
blocked from the signal path by an internal low-pass filter.
A.F. preamplifier
This stage preamplifies the audio frequency output signal. The amplifier output has an emitter follower with a series
resistor which, together with an external capacitor, yields the required low-pass for a.f. filtering.
A.G.C. amplifier
The a.g.c. amplifier provides a control voltage which is proportional to the carrier amplitude. Second-order filtering of the
a.g.c. voltage achieves signals with very little distortion, even at low audio frequencies. This method of filtering also gives
fast a.g.c. settling time which is advantageous for electronic search tuning. The a.g.c. settling time can be further reduced
by using capacitors of smaller value in the external filter (C16 and C17). The a.g.c. voltage is fed to the r.f. and i.f. stages
via suitable a.g.c. delays. The capacitor at pin 7 can be omitted for low-cost applications.
Field strength indicator output
A buffered voltage source provides a high-level field strength output signal which has good linearity for logarithmic input
signals over the whole dynamic range. If the field strength information is not needed, R
L(9)
can be omitted.
Standby switch
This switch is primarily intended for AM/FM band switching. During standby mode the oscillator, mixer and a.f.
preamplifier are switched off.
Short-circuit protection
All pins have short-circuit protection to ground.
May 1984
4
Philips Semiconductors
Product specification
AM receiver circuit
TDA1072A
RATINGS
Limiting values in accordance with the Absolute Maximum Rating System (IEC 134)
Supply voltage
V
P
= V
13-16
max.
20 V
Total power dissipation
P
tot
max.
875 mW
Input voltage
ï
V
14-15
ï
max.
12 V
-
V
14-16
,
-
V
15-16
max.
0,6 V
V
14-16
, V
15-16
max.
V
P
V
Input current
ï
I
14
ï
,
ï
I
15
ï
max.
200 mA
Operating ambient temperature range
T
amb
-
40 to
+
80
°
C
Storage temperature range
T
stg
-
55 to
+
150
°
C
Junction temperature
T
j
max.
+
125
°
C
THERMAL RESISTANCE
From junction to ambient
R
th j-a
=
80
K/W
DEVICE CHARACTERISTICS
V
P
= V
13-16
= 8,5 V; T
amb
= 25
°
C; f
i
= 1 MHz; f
m
= 400 Hz; m = 30%; f
if
= 460 kHz; measured in test circuit of Fig.1;
unless otherwise specified
PARAMETER
SYMBOL
MIN.
TYP. MAX.
UNIT
Supplies
Supply voltage
V
P
= V
13-16
7,5
8,5
18
V
Supply current
I
P
= I
13
15
23
30
mA
R.F. stage and mixer
Input voltage (d.c. value)
V
14-16
, V
15-16
-
V
P
/2
-
V
R.F. input impedance at V
i
<
300
m
V
R
14-16
, R
15-16
-
5,5
-
k
W
C
14-16
, C
15-16
-
25
-
pF
R.F. input impedance at V
i
>
10 mV
R
14-16
, R
15-16
-
8
-
k
W
C
14-16
, C
15-16
-
22
-
pF
I.F. output impedance
R
1-16
500
-
-
k
W
C
1-16
-
6
-
pF
Conversion transconductance
before start of a.g.c.
I
1
/V
i
-
6,5
-
mA/V
Maximum i.f. output voltage, inductive
coupling to pin 1
V
1-13(p-p)
-
5
-
V
D.C. value of output current (pin 1)
at V
i
= 0 V
I
1
-
1,2
-
mA
A.G.C. range of input stage
-
30
-
dB
R.F. signal handling capability:
input voltage for THD = 3% at m = 80%
V
i(rms)
-
500
-
mV
May 1984
5
Plik z chomika:
aos.artur2
Inne pliki z tego folderu:
tda1010a.pdf
(635 KB)
tda1170s.pdf
(319 KB)
tda1013b.pdf
(109 KB)
tda1072a.pdf
(648 KB)
tda1023.pdf
(266 KB)
Inne foldery tego chomika:
• Katalogi - Wielka baza układów scalonych
• Katalogi tranzystorów
4xxx
74xxx
7xxx
Zgłoś jeśli
naruszono regulamin