Product specification
Supersedes data of May 1994
File under Integrated Circuits, IC01
1997 Feb 27
Philips SemiconductorsProduct specification
IF amplifier/demodulator for FM radio receiversTDA1597
FEATURES
• Balanced limiting amplifier
• Balanced coincidence demodulator
• Two open-collector stop pulse outputs for
microcomputer tuning control
• Simulated behaviour of ratio detector (internal field
strength and detuning dependent voltage for dynamic
AF signal muting)
GENERAL DESCRIPTION
The TDA1597 provides IF amplification, symmetrical
quadrature demodulation and level detection for quality
home and car FM radio receivers and is suitable for mono
and stereo reception. It may also be applied to common
front-ends, stereo decoders and AM receivers circuits.
All pin numbers mentioned in this data sheet refer to the
SO version (TDA1597T) unless otherwise specified.
• Mono/stereo blend field strength indication control
voltage
• AFC output
• 3-state mode switch for FM-MUTE-ON, FM-MUTE-OFF
and FM-OFF
• Internal compensation of AF signal Total Harmonic
Distortion (THD)
• Built-in hum and ripple rejection circuits.
QUICK REFERENCE DATA
SYMBOLPARAMETERCONDITIONSMIN.TYP.MAX.UNIT
V
P
I
P
V
iIF(rms)
supply voltage7.58.512V
supply current (l2=I7=0)−2026mA
IF input sensitivity for limiting on pin 20
142235µV
(RMS value)
V
oAF(rms)
S/Nsignal-to-noise ratiof
AF output signal on pin 4 (RMS value)180200220mV
= 400 Hz;
m
−82−dB
∆f=±75 kHz
THDtotal harmonic distortionf
= 1 kHz;
m
−0.10.3%
∆f=±75 kHz
K2 adjustment and
−0.070.25%
FM-MUTE-OFF
T
amb
operating ambient temperature−40−+85°C
ORDERING INFORMATION
TYPE
NUMBER
NAMEDESCRIPTIONVERSION
PACKAGE
TDA1597DIP18plastic dual in-line package; 18 leads (300 mil)SOT102-1
TDA1597TSO20plastic small outline package; 20 leads; body width 7.5 mmSOT163-1
1997 Feb 272
1997 Feb 273
BLOCK DIAGRAM
Philips SemiconductorsProduct specification
IF amplifier/demodulator for FM radio receiversTDA1597
THD
(1)
V
FILTER
V
(11)
int
LP
1 MHz
ref
13
ATTENUATOR
MUTE
HP
FILTER
50 kHz
25 kΩ
TDA1597T
V
int
DETUNE
DETECTOR
47 nF
FM-OFF
MUTE-OFF
V
offset
STOP-0STOP-1
25 kΩ
16
15
(14)
(13)
V
int
MODE
×2
SWITCH
25 kΩ
14
(12)
+−
11 (10)
10
(9)
12
+5 V
9
n.c.
3.3
kΩ
QL =19
n.c.
100
pF
FM-IF
input
SFE
20
(18)
DETECTOR
LIMITING
AMPLIFIER
VOLTAGE
STABILIZER
LEVEL
330 Ω
V
ref
22 nF22 nF
19
(17)
40 kΩ
40
kΩ
25
kΩ
18
(16)
25 kΩ
7.5
kΩ
V
V
9 pF
int
int
9 pF
17
(15)
QUADRATURE
DEMODULATOR
COMPENSATION
1(1)2(2)3(3)4(4)
VP (+8.5 V)
V
ref
optional level shift
unweighted level
information
(FM-MUTE-ON)
(FM-MUTE-OFF)
The pin numbers given in parenthesis refer to the TDA1597.
(1) Connecting pin 13 (11) to ground is only allowed to measure the current on pin 16 (14).
(2) FM-MUTE-OFF.
(3) FM-OFF.
(4) FM-MUTE-ON.
Fig.1 Block diagram and application circuit.
V
ref
adjustment
for minimum
2nd harmonic
handbook, full pagewidth
5(5)6(6)
V
oAF
MPX signal weighted level
V
ref
information
7(7)8(8)
(2)(3)
(4)
MED829
100 nF
Philips SemiconductorsProduct specification
IF amplifier/demodulator for FM radio receiversTDA1597
PINNING
SYMBOL
DESCRIPTION
DIP18SO20
PIN
V
P
11supply voltage (+8.5 V)
LVA22level adjustment for stop condition
ULV33unweighted level output/K2 adjustment
V
IF amplifier/demodulator for FM radio receiversTDA1597
FUNCTIONAL DESCRIPTION
The limiter amplifier has five stages of IF amplification
using balanced differential limiter amplifiers with emitter
follower coupling.
Decoupling of the stages from the supply voltage line and
an internal high-ohmic DC feedback loop gives a very
stable IF performance. The amplifier gain is virtually
independent of changes in temperature.
The FM demodulator is fully balanced and contains two
cross-coupled differential amplifiers.
The quadrature detection of the FM signal is performed by
direct feeding of one differential amplifier from the limiter
amplifier output and the other via an external 90 degrees
phase shifting network. The demodulator has a good
stability and a small zero cross-over shift. The bandwidth
of the demodulator output is restricted by an internal
low-pass filter to approximately 1 MHz. Non-linearities,
which are introduced by demodulation, are compensated
for by the THD compensation circuit. For this reason, the
demodulator resonance circuit (between pins 10 and 11)
must have a loaded Q-factor of 19.
Consequently, there is no need for the demodulator tuned
circuit to be adjusted for minimum distortion. Adjustment
criterion is a symmetrical stop pulse. The control voltage
for the mute attenuator (pin 16) is derived from the values
of the level detector and the detuning detector output
signals. The mute attenuator has a fast attack and a slow
decay, determined by the capacitor connected to pin 16.
The AF signal is fed via the mute attenuator to the output
(pin 4). A weighted control voltage (pin 6) is obtained from
the mute attenuator control voltage via a buffer amplifier
that introduces an additional voltage shift and gain.
The level detector generates a voltage output signal
proportional to the amplitude of the input signal.
The unweighted level detector output signal is available in
the FM-MUTE-ON condition (mode switch).
The open-collector tuning stop output voltages STOP-0
and STOP-1 (pins 15 and 14) are derived from the
detuning and the input signal level. Pins 14 and 15 may be
tied together if only one tuning-stop output is required.
LIMITING VALUES
In accordance with the Absolute Maximum Rating System (IEC 134).
SYMBOLPARAMETERCONDITIONSMIN.MAX.UNIT
V
P
V
n
supply voltage−0.3+13V
voltage at pins 2, 4, 5, 6, 10, 11 and 16−0.3+10V
voltage at pins 3, 7, 8, 14, 15, 18,
−0.3V
P
V
19 and 20
V
13
I
14, 15
P
tot
T
stg
T
amb
V
es
voltage on pin 13−6V
current at pins 14 and 15−2mA
total power dissipation−360mW
storage temperature−55+150°C
operating ambient temperature−40+85°C
electrostatic handling
all pins except pins 5 and 7note 1−2000+2000V
pin 5note 1−2000+800V
pin 7note 1−2000+1000V
Note
1. Equivalent to discharging a 100 pF capacitor through a 1.5 kΩ series resistor.
1997 Feb 275
Philips SemiconductorsProduct specification
IF amplifier/demodulator for FM radio receiversTDA1597
THERMAL CHARACTERISTICS
SYMBOLPARAMETERVALUEUNIT
R
th j-a
CHARACTERISTICS
= 8.5 V; T
V
P
Vi= 10 mV (RMS) at pin 20; de-emphasis of 50 µs; tuned circuit at pins 10 and 11 aligned for symmetrical stop pulses;
measurements taken in Fig.4; unless otherwise specified.
SYMBOLPARAMETERCONDITIONSMIN.TYP.MAX.UNIT
V
P
I
P
Mode switch input
I
7
V
7
thermal resistance from junction to ambient in free air
IF amplifier/demodulator for FM radio receiversTDA1597
OPERATING CHARACTERISTICS
VP= 7.5 to 12 V; T
Vi= 10 mV (RMS) at pin 20; de-emphasis of 50 µs; tuned circuit at pins 10 and 11 aligned for symmetrical stop pulses;
measurements taken in Fig.4; unless otherwise specified.
SYMBOLPARAMETERCONDITIONSMIN.TYP.MAX.UNIT
IF amplifier and demodulator
V
i(rms)
input signal for start of limiting
(−3 dB) (RMS value; pin 20)
input signal for signal-to-noise
ratio (RMS value)