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TDA1572
Datasheet (Philips)
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Datasheet TDA1572 Datasheet (Philips)

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Page 1
DATA SH EET
Product specification File under Integrated Circuits, IC01
December 1987
INTEGRATED CIRCUITS
TDA1572
AM receiver circuit
Page 2
December 1987 2
AM receiver circuit TDA1572
GENERAL DESCRIPTION
The TDA1572 integrated AM receiver circuit performs all the active functions and part of the filtering required 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 RF signals up to 500 mV.
RF radiation and sensitivity to interference are minimized by an almost symmetrical design. The controlled-voltage 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 IF amplifier.
Features
• Inputs protected against damage by static discharge
• Gain-controlled RF stage
• Double balanced mixer
• Separately buffered, voltage-controlled and temperature-compensated oscillator, designed for simple coils
• Gain-controlled IF stage with wide AGC range
• Full-wave, balanced envelope detector
• Internal generation of AGC voltage with possibility of second-order filtering
• Buffered field strength indicator driver with short-circuit protection
• AF preamplifier with possibilities for simple AF filtering
• Electronic standby switch
• IF output for stereo demodulator and search tuning.
QUICK REFERENCE DATA
PACKAGE OUTLINE
18-lead DIL; plastic (SOT102); SOT102-1; 1996 August 12.
PARAMETER SYMBOL MIN. TYP. MAX. UNIT
Supply voltage range V
P
7,5 − 18,0 V
Supply current range I
P
15 − 30 mA
RF input voltage
for (S+N)/N = 6 dB at m = 30% V
i(RF)
− 1,5 −µV
RF input voltage for 3% total
harmonic distortion (THD) at m = 80% V
i(RF)
− 500 − mV
IF output voltage with V
i
= 2 mV V
o(IF)
− 230 − mV
AF output voltage with V
i
= 2 mV;
f
i
= 1 MHz; m = 30%; fm = 400 Hz V
o(AF)
− 310 − mV
AGC range: change of V
i
for
1 dB change of V
o(AF)
− 86 − dB
Field strength indicator voltage at V
i
= 500 mV;
R
L(11)
= 2,7 kΩ V
IND
− 2,8 − V
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AM receiver circuit TDA1572
Fig.1 Block diagram and test circuit (connections shown in broken lines are not part of the test circuit).
(1) Coil data: TOKO sample no. 7XNS-A7523DY; L1 : N1/N2 = 12/32; Q
o
= 65; Q
B
= 57.
Filter data: Z
F
= 700 Ω at R
3-4
= 3 kΩ; Z
I
= 4,8 kΩ.
(2) AF output is pin 6 is not used.
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AM receiver circuit TDA1572
FUNCTIONAL DESCRIPTION Gain-controlled RF stage and mixer
The differential amplifier in the RF stage employs an AGC negative feedback network to provide a wide dynamic range. Very good cross-modulation behaviour is achieved by AGC delays at the various signal stages. Large signals are handled with low distortion and the (S+N)/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 IF 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
13-18
. An extra
buffered oscillator output (pin 12) is available for driving a synthesizer. If this is not needed, resistor R
L(12)
can be omitted.
Gain-controlled IF amplifier
This amplifier comprises two cascaded, variable-gain differential amplifier stages coupled by a band-pass filter. Both stages are gain-controlled by the AGC negative feedback network. The IF output is available at pin 10.
Detector
The full-wave, balanced envelope detector has very low distortion over a wide dynamic range. Residual IF carrier is blocked from the signal path by an internal low-pass filter.
AF 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 AF filtering.
AGC amplifier
The AGC amplifier provides a control voltage which is proportional to the carrier amplitude. Second-order filtering of the AGC voltage achieves signals with very little distortion, even at low audio frequencies. This method of filtering also gives fast AGC settling time which is advantageous for electronic search tuning. The AGC settling time can be further reduced by using capacitors of smaller value in the external filter (C16 and C17). The AGC voltage is fed to the RF and IF stages via suitable AGC 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(11)
can be omitted.
Standby switch
This switch is primarily intended for AM/FM band switching. During standby mode the oscillator, mixer and AF preamplifier are switched off.
Short-circuit protection
All pins have short-circuit protection to ground.
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December 1987 5
AM receiver circuit TDA1572
RATINGS
Limiting values in accordance with the Absolute Maximum Rating System (IEC 134)
THERMAL RESISTANCE
PARAMETER SYMBOL MIN. MAX. UNIT
Supply voltage V
P
= V
15-18
− 20 V
Total power dissipation P
tot
− 875 mW
Input voltage V
16-17
−12 V
−V
16-18,−V17-18
− 0,6 V
V
16-18
, V
17-18
− V
P
V
Input current I
16
, I18−200 mA
Operating ambient temperature range T
amb
−40 + 85 °C
Storage temperature range T
stg
−55 + 150 °C
Junction temperature T
j
−+ 125 °C
From junction to ambient R
th j-a
80 K/W
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AM receiver circuit TDA1572
CHARACTERISTICS
V
P
= V
15-18
= 8,5 V; T
amb
= 25 °C; fi = 1 MHz; fm = 400 Hz; m = 30%; fIF = 460 kHz; measured in test circuit of Fig.1; all
voltages referenced to ground; unless otherwise specified.
PARAMETER SYMBOL MIN. TYP. MAX. UNIT
Supply
Supply voltage (pin 15) V
P
7,5 8,5 18,0 V
Supply current (pin 15) I
P
15 23 30 mA RF stage and mixer (pins 16 and 17) DC input voltage V
I
− VP/2 − V
RF input impedance at V < 300 µVZ
i
−5,5 − kΩ
RF input capacitance C
i
− 25 − pF
RF input impedance at V
I
> 10 mV Z
i
− 8 − kΩ
RF input capacitance C
i
− 22 − pF
IF output impedance (pin 1) Z
o
200 −−kΩ IF output capacitance C
o
− 6 − pF
Conversion transconductance
before start of AGC I
1/Vi
− 6,5 − mA/V
Maximum IF output voltage, inductive
coupling to pin 1 (peak-to-peak value) V
1-15(p-p)
− 5 − V
DC value of output current;
at V
I
= 0 V (pin 1) I
O
− 1,2 − mA AGC range of input stage − 30 − dB RF signal handling capability:
(r.m.s. value): input voltage for THD = 3% at m = 80% V
i(rms)
− 500 − mV
Oscillator
Frequency range f
osc
0,1 − 60 MHz Oscillator amplitude (pins 13 to 14) V − 130 150 mV External load impedance (pins 14 to 13) R
(ext)
0,5 − 200 kΩ External load impedance for no
oscillation (pins 14 to 13) R
(ext)
−−60 Ω
Ripple rejection at V
P(rms)
= 100 mV;
f
p
= 100 Hz
(SVRR = 20 log [V
15/V13
]) RR − 55 − dB
Source voltage for switching diodes
(6 × V
BE
) (pin 13) V − 4,2 − V
DC output current (for switching
diodes) (pin 13) −I
O
0 − 20 mA Change of output voltage at
∆l13 = 20 mA (switch to maximum load) (pin 13) ∆V
I
− 0,3 − V
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AM receiver circuit TDA1572
Buffered oscillator output (pin 12) DC output voltage V
O
− 0,8 − V
Output signal amplitude
(peak-to-peak value) V
o(p-p)
− 320 − mV
Output impedance Z
O
− 170 −Ω
Output current −I
O(peak)
−−3mA
IF, AGC and AF stages
DC input voltage (pins 3 and 4) V
I
− 2,0 − V
IF input impedance (pins 3 to 4) Z
i
2,4 3,0 3,9 kΩ IF input capacitance C
i
− 7 − pF
IF input voltage for
THD = 3% at m = 80% (pins 3 and 4) V
i
− 90 − mV
IF output impedance (pin 10) Z
o
− 50 −Ω
Unloaded IF output voltage
at V
i
= 10 mV (pin 10) V
o
180 230 290 mV Voltage gain before start of AGC
(pins 3 to 4; 6 to 18) G
v
− 68 − dB
AGC range of IF stages: change of
V
3-4
for 1 dB change of V
o(AF);
V
3-4 (ref)
= 75 mV ∆V
v
− 55 − dB
AF output voltage at V
3-4(IF)
= 50 µVV
o(AF)
− 130 − mV
AF output voltage at V
3-4(IF)
= 1 mV V
o(AF)
− 310 − mV
AF output impedance (pin 6) Z
o
2,8 3,5 4,2 kΩ Indicator driver (pin 11) Output voltage at Vi = 0 mV;
R
L
= 2,7 kΩ V
o
−−140 mV
Output voltage at V
i
= 500 mV;
R
L
= 2,7 kΩ V
o
2,5 2,8 3,1 V
Load resistance R
L
1,5 −−kΩ
Standby switch
Switching threshold at;
V
P
= 7,5 to 18 V
T
amb
= −40 to +80 °C
ON-voltage V
2-1
0 − 2,0 V
OFF-voltage V
2-1
3,5 − 20,0 V
ON-current at V
2-1
= 0 V −I
2
− 100 200 µA
OFF-current at V
2-1
= 20 V I2−−10 µA
PARAMETER SYMBOL MIN. TYP. MAX. UNIT
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December 1987 8
AM receiver circuit TDA1572
OPERATING CHARACTERISTICS
V
P
= 8,5 V; fi = 1 MHz; m = 30%; fm = 400 Hz; T
amb
= 25 °C; measured in Fig.1; unless otherwise specified
PARAMETER SYMBOL MIN. TYP. MAX. UNIT
RF sensitivity
RF input required for (S+N)/N = 6 dB V
i
− 1,5 −µV
RF input required for (S+N)/N = 26 dB V
i
− 15 −µV
RF input required for (S+N)/N = 46 dB V
i
− 150 −µV
RF input at start of AGC V
i
− 30 −µV
RF large signal handling
RF input at THD = 3%; m = 80% V
i
− 500 − mV
RF input at THD = 3%; m = 30% V
i
− 700 − mV
RF input at THD = 10%; m = 30% V
i
− 900 − mV
AGC range
Change of V
i
for 1 dB change
of V
o(AF)
; V
i(ref)
= 500 mV ∆V
i
− 86 − dB
Change of V
i
for 6 dB change
of V
o(AF)
; V
i(ref)
= 500 mV ∆V
i
− 91 − dB
Output signal
IF output voltage at Vi = 2 mV V
o(IF)
180 230 290 mV
AF output voltage at
V
i
= 4 µV; m = 80% V
o(AF)
− 130 − mV
AF output voltage at V
i
= 2 mV V
o(AF)
240 310 390 mV
THD at V
i
= 1 mV d
tot
− 0,5 − %
THD at V
i
= 500 mV d
tot
− 1 − %
Signal plus noise-to-noise ratio
at V
i
= 100 mV (S+N)/N − 58 − dB
Ripple rejection at V
i
= 2 mV;
V
P(rms)
= 100 mV; fp = 100 Hz
(SVRR = 20 log [V
P/Vo(AF)
]) RR − 38 − dB a) additional AF signal at IF output RR − 0* − dB b) add modulation at IF output (m
ref
= 30%) RR − 40 − dB
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December 1987 9
AM receiver circuit TDA1572
* AF signals at the IF output will be suppressed by a coupling capacitor to the demodulator and by full wave-detection in
the demodulator.
** Value to be fixed.
APPLICATION INFORMATION
Unwanted signals
Suppression of IF whistles at
V
i
= 15 µV; m = 0% related to AF signal of m = 30% at f
i
≈ 2 × f
IF
α
2IF
− ** − dB
at f
i
≈ 3 × f
IF
α
3IF
− ** − dB
IF suppression at RF input;
for symmetrical input α
IF
− 40 − dB
for asymmetrical input α
IF
− 40 − dB
Residual oscillator signal at mixer output;
at f
osc
I
1(osc)
− 1 −µA
at 2 × f
osc
I
1(2osc)
− 1,1 −µA
PARAMETER SYMBOL MIN. TYP. MAX. UNIT
Fig.2 Oscillator circuit using quartz crystal; centre frequency = 27 MHz.
(1) Capacitor values depend on crystal type. (2) Coil data: 9 windings of 0,1 mm dia laminated Cu wire on TOKO coil set 7K 199CN; Qo = 80.
Page 10
December 1987 10
AM receiver circuit TDA1572
Fig.3 AF output as a function of RF input in the
circuit of Fig.1; fi = 1 MHz; fm = 400 Hz; m = 30%.
Fig.4 Total harmonic distortion and (S + N)/N as
functions of RF input in the circuit of Fig.1; m = 30% for (S + N)/N curve and m = 80% for THD curve.
Fig.5 Total harmonic distortion as a function of modulation frequency at Vi = 5 mV; m = 80%; measured in the
circuit of Fig.1 with C
7-18(ext)
= 0 µF and 2,2 µF.
Page 11
December 1987 11
AM receiver circuit TDA1572
Fig.6 Indicator driver voltage as a function of RF
input in the circuit of Fig.1.
Fig.7 Typical frequency response curves from
Fig.1 showing the effect of filtering as follows:
 with IF filter;  -  -  with AF filter;
− − − − − − with IF and AF filters.
Fig.8 Car radio application with inductive tuning.
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December 1987 12
AM receiver circuit TDA1572
Fig.9 AF output as a function of RF input using the circuit of Fig.8 with that of Fig.1.
Fig.10 Suppression of cross-modulation as a function of input signal, measured in the circuit of Fig.8 with the
input circuit as shown in Fig.11. Curve is for Wanted V
o(AF)
/Unwanted V
o(AF)
= 20 dB; V
rfw,Vrfu
are signals
at the aerial input, V’
aew,
V’
aeu
are signals at the unloaded output of the aerial.
Wanted signal (V’
aew, Vrfw
): fi = 1 MHz; fm = 400 Hz; m = 30%.
Unwanted signal (V’
aeu,
V’
rfu
): fi = 900 kHz; fm = 400 Hz; m = 30%.
Effective selectivity of input tuned circuit = 21 dB.
Page 13
December 1987 13
AM receiver circuit TDA1572
Fig.11 Input circuit to show cross-modulation suppression (see Fig.10).
Fig.12 Oscillator amplitude as a function of pin 13, 14 impedance in the circuit of Fig.8.
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December 1987 14
AM receiver circuit TDA1572
Fig.13 Total harmonic distortion and (S +N)/N as functions of RF input using the circuit of Fig.8 with that of Fig.1.
Fig.14 Forward transfer impedance as a function of intermediate frequency for filters 1 to 4 shown in Fig.15;
centre frequency = 455 kHz.
Page 15
December 1987 15
AM receiver circuit TDA1572
Fig.15 IF filter variants applied to the circuit of Fig.1. For filter data, refer to Table 1.
Page 16
December 1987 16
AM receiver circuit TDA1572
Fig.16 IF output voltage as a function of RF input in the circuit of Fig.1; fi = 1 MHz.
Page 17
December 1987 17
AM receiver circuit TDA1572
Table 1 Data for IF filters shown in Fig.15. Criteria for adjustment is Z
F
= maximum (optimum selectivity curve at centre frequency f
0
= 455 kHz).
See also Fig.14.
* The beginning of an arrow indicates the beginning of a winding; N1 is always the inner winding, N2 the outer winding.
FILTER NO. 1 2 3 4 UNIT
Coil data L1 L1 L1 L2 L1
Value of C 3900 430 3900 4700 3900 pF
N1: N2 12 : 32 13 : (33 + 66) 15 : 31 29 : 29 13 : 31
Diameter of Cu
laminated wire 0,09 0,08 0,09 0,08 0,09 mm
Q
o
65 (typ.) 50
75
60 75
Schematic*
of
windings
(N1) (N2)
Toko order no. 7XNS-A7523DY L7PES-A0060BTG 7XNS-A7518DY 7XNS-A7521AIH 7XNS-A7519DY
Resonators
Murata type SFZ455A SFZ455A SFZ455A SFT455B
D (typical value) 4 4 4 6 dB
R
G
, R
L
33 33kΩ
Bandwidth (−3 dB) 4,2 4,2 4,2 4,5 kHz
S
9kHz
24 24 24 38 dB
Filter data
Z
I
4,8 3,8 4,2 4,8 kΩ
Q
B
57 40 52 (L1) 18 (L2) 55
Z
F
0,70 0,67 0,68 0,68 kΩ
Bandwidth (−3 dB) 3,6 3,8 3,6 4,0 kHz
S
9kHz
35 31 36 42 dB
S
18kHz
52 49 54 64 dB
S
27kHz
63 58 66 74 dB
12 32
661333
15 31
29
29
13 31
Page 18
December 1987 18
AM receiver circuit TDA1572
PACKAGE OUTLINE
REFERENCES
OUTLINE VERSION
EUROPEAN
PROJECTION
ISSUE DATE
IEC JEDEC EIAJ
SOT102-1
93-10-14 95-01-23
UNIT
A
max.
12
b
1
(1) (1)
(1)
b
2
cD E e M
Z
H
L
mm
DIMENSIONS (inch dimensions are derived from the original mm dimensions)
A
min.
A
max.
b
max.
w
M
E
e
1
1.40
1.14
0.53
0.38
0.32
0.23
21.8
21.4
6.48
6.20
3.9
3.4
0.2542.54 7.62
8.25
7.80
9.5
8.3
0.854.7 0.51 3.7
inches
0.055
0.044
0.021
0.015
0.013
0.009
1.40
1.14
0.055
0.044
0.86
0.84
0.26
0.24
0.15
0.13
0.010.10 0.30
0.32
0.31
0.37
0.33
0.0330.19 0.020 0.15
M
H
c
(e )
1
M
E
A
L
seating plane
A
1
w M
b
1
b
2
e
D
A
2
Z
18
1
10
9
b
E
pin 1 index
0 5 10 mm
scale
Note
1. Plastic or metal protrusions of 0.25 mm maximum per side are not included.
DIP18: plastic dual in-line package; 18 leads (300 mil)
SOT102-1
Page 19
December 1987 19
AM receiver circuit TDA1572
SOLDERING Introduction
There is no soldering method that is ideal for all IC packages. Wave soldering is often preferred when through-hole and surface mounted components are mixed on one printed-circuit board. However, wave soldering is not always suitable for surface mounted ICs, or for printed-circuits with high population densities. In these situations reflow soldering is often used.
This text gives a very brief insight to a complex technology. A more in-depth account of soldering ICs can be found in our
“IC Package Databook”
(order code 9398 652 90011).
Soldering by dipping or by wave
The maximum permissible temperature of the solder is 260 °C; solder at this temperature must not be in contact with the joint for more than 5 seconds. The total contact time of successive solder waves must not exceed 5 seconds.
The device may be mounted up to the seating plane, but the temperature of the plastic body must not exceed the specified maximum storage temperature (T
stg max
). If the printed-circuit board has been pre-heated, forced cooling may be necessary immediately after soldering to keep the temperature within the permissible limit.
Repairing soldered joints
Apply a low voltage soldering iron (less than 24 V) to the lead(s) of the package, below the seating plane or not more than 2 mm above it. If the temperature of the soldering iron bit is less than 300 °C it may remain in contact for up to 10 seconds. If the bit temperature is between 300 and 400 °C, contact may be up to 5 seconds.
DEFINITIONS
LIFE SUPPORT APPLICATIONS
These products are not designed for use in life support appliances, devices, or systems where malfunction of these products can reasonably be expected to result in personal injury. Philips customers using or selling these products for use in such applications do so at their own risk and agree to fully indemnify Philips for any damages resulting from such improper use or sale.
Data sheet status
Objective specification This data sheet contains target or goal specifications for product development. Preliminary specification This data sheet contains preliminary data; supplementary data may be published later. Product specification This data sheet contains final product specifications.
Limiting values
Limiting values given are in accordance with the Absolute Maximum Rating System (IEC 134). Stress above one or more of the limiting values may cause permanent damage to the device. These are stress ratings only and operation of the device at these or at any other conditions above those given in the Characteristics sections of the specification is not implied. Exposure to limiting values for extended periods may affect device reliability.
Application information
Where application information is given, it is advisory and does not form part of the specification.
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