PHILIPS TDA3845

INTEGRATED CIRCUITS
DATA SHEET
TDA3845; TDA3845T
Quasi split-sound circuit and AM
demodulator
Objective specification
File under Integrated Circuits, IC02
January 1993
Philips Semiconductors
Objective specification
Quasi split-sound circuit and AM
demodulator
TDA3845; TDA3845T
• Stabilizer circuit for ripple rejection and constant output
signals
FEATURES
• Power supply from 5 V (200 mW) to 8 V source also an
alternative 12 V source (12 V not for TDA3845T)
• ESD protection for all pins
• Gain controlled wideband IF amplifier (AC coupled with
three stages)
• Suitable for all FM standards and L as well as L-accent
standard
• High precision internal 90° phase shifter for quadrature
demodulator
• NICAM compatible.
• Amplitude detector for gain control which operates as a
peak detector for FM sound and as a mean level
detector for AM sound (switchable)
GENERAL DESCRIPTION
The TDA3845 is a quasi split-sound IF circuit which is
designed to provide high performance television FM/AM
sound.
• In-phase wideband synchronous demodulator for AM
detection
QUICK REFERENCE DATA
SYMBOL
PARAMETER
MIN.
TYP.
MAX.
UNIT
positive supply voltage
VP1
pin 14
4.5
5.0
8.8
V
VP2
pin 11 (not for TDA3845T)
10.8
12.0
13.2
V
−
mA
IP
supply current
−
40
V1-16(RMS)
minimum IF input voltage (RMS value)
−
70
100
µV
IF control range
60
63
−
dB
V12-13(RMS)
intercarrier output voltage 5.5 MHz (RMS value)
70
100
−
mV
(S +W)/W
signal-to-weighted-noise ratio
(relative to 1 kHz; 50 kHz deviation)
at 5.5 MHz for 2T/20T
−
60
−
dB
at 5.742 MHz for 2T/20T
−
58
−
dB
V6-13(RMS)
AF output voltage AM (RMS value)
440
550
660
mV
(S +W)/W
signal-to-weighted-noise ratio; AM mode
−
56
−
dB
THD
total harmonic distortion; AM mode
−
1
2
%
Tamb
operating ambient temperature
0
−
+70
°C
ORDERING INFORMATION
EXTENDED
TYPE NUMBER
PACKAGE
PINS
PIN POSITION
MATERIAL
CODE
TDA3845
16
DIL
plastic
SOT38(1)
TDA3845T
16
SO16
plastic
SOT109A(2)
Note
1. SOT38-1; 1996 November 28.
2. SOT109-1; 1996 November 28.
January 1993
2
Philips Semiconductors
Objective specification
Quasi split-sound circuit and AM
demodulator
TDA3845; TDA3845T
(1) See note 10 to the characteristics.
(2) Not for TDA3845T, pin 11 not connected.
Fig.1 Block diagram.
January 1993
3
Philips Semiconductors
Objective specification
Quasi split-sound circuit and AM
demodulator
TDA3845; TDA3845T
PINNING
SYMBOL
(1) not for TDA3845T, pin 11 not connected.
Fig.2 Pin configuration.
PIN
DESCRIPTION
IF2
1
IF amplifier input 2
n.c.
2
not connected
AGC
3
AGC control capacitor
OPT
4
optional capacitor (see note 10 to
the characteristics)
PMD
5
peak/mean detector capacitor
AM
6
AM output
SW
7
FM/AM switch
LCREF
8
LC reference circuit for the picture
carrier
LCREF
9
LC reference circuit for the picture
carrier
n.c.
10
not connected
VP2
11
positive supply voltage 2
(+12 V); note 1
ICO
12
intercarrier output
GND
13
ground (0 V)
VP1
14
positive supply voltage 1 (+5 V)
n.c.
15
not connected
IF1
16
IF amplifier input 1
Note to Pinning
1. Not for TDA3845T, pin 11 not connected.
LIMITING VALUES
In accordance with the Absolute Maximum Rating System (IEC134)
SYMBOL
PARAMETER
MIN.
MAX.
UNIT
supply voltage
VP1
pin 14
4.5
8.8
V
VP2
pin 11 (not for TDA3845T)
10.8
13.2
V
Tamb
operating ambient temperature
0
+70
°C
Tstg
storage temperature
−25
+125
°C
January 1993
4
Philips Semiconductors
Objective specification
Quasi split-sound circuit and AM
demodulator
TDA3845; TDA3845T
CHARACTERISTICS
VP1 = 5 V (note 11); Tamb = 25 °C; all measurements are referenced to ground (pin 13); unless otherwise specified.
SYMBOL
PARAMETER
CONDITIONS
MIN.
TYP.
MAX.
UNIT
Supply
supply voltage
VP1
pin 14
4.5
5.0
8.8
V
VP2
pin 11 (not for TDA3845T)
10.8
12.0
13.2
V
total supply current
−
40
48
mA
R1-16
input resistance
−
2
−
kΩ
C1-16
input capacitance
−
2.5
−
pF
V1-16(RMS)
minimum IF input voltage
(RMS value)
note 1
−
70
100
µV
V1-16(RMS)
maximum IF input voltage
(RMS value)
note 2
70
100
−
mV
Itot
IF amplifier
∆G
gain control range
60
63
−
dB
Gv3-16
gain control voltage range
1.5
−
3.0
V
BIF
IF bandwidth
50
70
−
MHz
V1-16
DC potential
−
1.7
−
V
−3 dB
Intercarrier mode (FM mode; standard B/G) notes 3, 4 and 5
Reference amplifier
V8-9(p-p)
picture carrier amplitude
(peak-to-peak value)
−
270
−
mV
R8-9
operating resistance
−
4
−
kΩ
V8-9
DC potential
−
3.9
−
V
at 5.5 MHz
70
100
−
mV
at 5.74 MHz
32
45
−
mV
−
8
−
MHz
−
9
−
MHz
−
3
10
%
−
30
−
Ω
−
1.8
−
V
−
−
±0.7
mA
−
−
−2
mA
Intercarrier mixer and output stage
V12(RMS)
B12
output signal (RMS value)
intercarrier bandwidth
at −1 dB
at −3 dB
residual video AM on intercarrier
signal
R12
output resistance
V12
DC potential
I12(peak)
permissible AC output current
(peak value)
I12
permissible DC output current
January 1993
note 6
note 7
5
Philips Semiconductors
Objective specification
Quasi split-sound circuit and AM
demodulator
SYMBOL
TDA3845; TDA3845T
PARAMETER
CONDITIONS
MIN.
TYP.
MAX.
UNIT
AF signal performance (note 8)
(S +W)/W
black picture
60/58
68/64
−
dB
(S +W)/W
2T/20T pulses with white bars
57/55
60/58
−
dB
(S +W)/W
6 kHz sinewave
(black-to-white modulation)
53/51
57/55
−
dB
(S +W)/W
250 kHz square wave
(black-to-white modulation)
50/44
56/50
−
dB
AM mode (standard L) note 9
S/N weighted in accordance with CCIR 468-3
V6(RMS)
AF output signal (RMS value)
BAF
AF bandwidth
THD
total harmonic distortion
−3 dB; note 12
440
550
660
mV
0.02
−
120
kHz
−
1
2
%
(S +W)/W
signal-to-weighted-noise ratio
50
56
−
dB
R6
output resistance
−
200
−
Ω
V6
DC potential
−
1.8
−
V
I6(peak)
permissible AC output current
(peak value)
−
−
±0.3
mA
I6
permissible DC output current
−
−
−1
mA
VP1 used
1.8
−
VP1
V
VP2 used
1.8
−
5.5
V
−
−
0.8
V
note 10
note 7
Standard switch (note 4)
V7
V7
peak signal AGC (FM mode)
or switch open-circuit
V7
mean signal AGC (AM mode)
I7
switch current
at 0 V
−
−
−200
µA
at VP1
−
−
10
µA
−
−
2.5
mA
30
40
−
dB
−
10
20
Hz
at VP2
via a 2.2 kΩ series resistor
Ripple rejection (note 13)
AM/AF signal
αRR
voltage ripple on VP/
voltage ripple on output signal
FM phase noise
∆f(RMS)
January 1993
intercarrier signal
6
Philips Semiconductors
Objective specification
Quasi split-sound circuit and AM
demodulator
SYMBOL
TDA3845; TDA3845T
PARAMETER
CONDITIONS
MIN.
TYP.
MAX.
UNIT
AM mode (standard L) note 9
S/N weighted in accordance with CCIR 468-3
V6(RMS)
AF output signal (RMS value)
440
550
660
mV
BAF
AF bandwidth
0.02
−
120
kHz
THD
total harmonic distortion
(S +W)/W
signal-to-weighted-noise ratio
−
1
2
%
50
56
−
dB
R6
output resistance
−
200
−
Ω
V6
DC potential
I6(peak)
permissible AC output current
(peak value)
−
1.8
−
V
−
−
±0.3
mA
I6
permissible DC output current
−
−
−1
mA
VP1 used
1.8
−
VP1
V
VP2 used
1.8
−
5.5
V
−
−
0.8
V
at 0 V
−
−
−200
µA
at VP1
−
−
10
µA
−
−
2.5
mA
30
40
−
dB
−
10
20
Hz
−3 dB; note 12
note 10
note 7
Standard switch (note 4)
V7
V7
peak signal AGC (FM mode)
or switch open-circuit
V7
mean signal AGC (AM mode)
I7
switch current
at VP2
via a 2.2 kΩ series resistor
Ripple rejection (note 13)
AM/AF signal
αRR
voltage ripple on VP/
voltage ripple on output signal
FM phase noise
∆f(RMS)
January 1993
intercarrier signal
7
Philips Semiconductors
Objective specification
Quasi split-sound circuit and AM
demodulator
TDA3845; TDA3845T
Notes to the characteristics
1. Start of gain control (LOW IF input signal) at −3 dB intercarrier signal reduction at pin 12, AGC mode set to FM or
−3 dB AF signal reduction at pin 6, AGC mode set to AM.
2. End of gain control (HIGH IF input signal) at +1 dB intercarrier signal expansion at pin 12, AGC mode set to FM or
+1 dB AF signal expansion at pin 6, AGC mode set to AM.
3. Picture carrier (38.9 MHz) to sound carriers (33.4 MHz/33.158 MHz) ratio: 13/20 dB.
IF input signal (picture carrier at sync pulse); V1-16 = 10 mV (RMS). Transmitter mode: DSB.
Reference for the (S + W)/W ratio (0 dB) corresponds to the sound modulation where f = 1 kHz and frequency
deviation ∆f = ± 50 kHz.
With reduced frequency deviation ∆f = ± 27 kHz and the (S + W)/W figures will decrease by 5.4 dB.
4. If the device is used only for the B/G standard (no AM), the capacitor at pin 5 can be omitted (pin 5 has to be
disconnected). In this event the AGC will always operate as a peak signal AGC and is independent of the voltage at
pin 7.
The AM mode can also be used for the B/G standard, consequently standard switching is not required. However, the
intercarrier level depends on the video modulation and the AF performance may decrease.
When the IC is operated from a 12 V power supply pin 7 can be connected to a 12 V logic level via a 2.2 kΩ resistor.
5. LC reference circuit for the picture carrier (pins 8 and 9); 68 pF/0.247 µH; in series with 27 pF:
Q loaded = 40 (Qo = 90); tuned to 38.9 MHz yields quadrature demodulation for the picture carrier which provides
optimum video suppression at the intercarrier output (e.g. black-to-white jump of the video modulation.The series
capacitor provides a notch at the sound carrier frequency in order to produce more attenuation for the sound carrier
in the PC reference channel. The ratio of parallel to series capacitance depends on the ratio of picture to sound
carrier frequency which has to be adapted to other TV transmission standards, if required, in accordance with the
formula:
C S = C P ( f PC ⁄ f SC ) 2 – C P
Where:
CS = series capacitor
C = parallel capacitor
fPC = picture carrier frequency
fSC = sound carrier frequency
The result is an improved ‘intercarrier buzz’ in the stereo system B/G, particularly with 250 kHz video modulation
(up to 10 dB improvement in sound Channel 2), or to suppress 350 kHz video modulated beat in the digitally
modulated NICAM subcarrier
In order to optimize the AF signal performance, fine tuning to the optimum S/W at the sound Channel 2 may be
achieved by a 250 kHz video modulated square wave.
6. Residual video AM is defined as:
m = (A−B)/A
A = intercarrier level at sync pulse
B = intercarrier level at 100% white video modulation
7. If higher AC output current is required an external resistor must be connected between the output pin and ground in
order to increase the bias current of the emitter follower. The permissible maximum DC output current must not be
exceeded.
January 1993
8
Philips Semiconductors
Objective specification
Quasi split-sound circuit and AM
demodulator
TDA3845; TDA3845T
8. For all S/N measurements the used vision IF modulator must conform to the following:
Incidental phase modulation for black-to-white jump should be less than 0.5 degrees. Intercarrier performance,
measured with the television demodulator AMF2 (intercarrier mode weighted S/N ratio) better than 60 dB for 6 kHz
sinewave black-to-white video modulation. Weighted S/N ratio of the demodulated intercarrier signals in accordance
with CCIR 468-3, measured with de-emphasis of 50 µs.
The indicated (S + W)/W ratio X/Y concerns the sound channels 1 and 2 that means demodulated intercarrier signals
of 5.5 and 5.74 MHz respectively.
9. Sound carrier frequency in the range of 30 to 40 MHz modulated with f = 1 kHz and a modulation depth of 80%.
IF input signal (sound carrier) V1-16 = 10 mV (RMS).
10. The capacitor at pin 4 can be omitted, however, the (S + W)/W figure for the AM sound (standard L) will be up to
8 dB worse in the IF voltage range 1 mV to 100 mV.
11. When the supply at VP2 = 12 V the performance will be comparable with the performance when VP1 = 5 to 8 V.
The power supply pin that is not in use should be disconnected.
12. The maximum value given as minimum 120 kHz and typical 700 kHz.
13. Voltage ripple < 200 mV (p-p) at 70 Hz.
January 1993
9
Philips Semiconductors
Objective specification
Quasi split-sound circuit and AM
demodulator
TDA3845; TDA3845T
(1) See note 5 to the characteristics.
Fig.3 Test circuit for the +5 V supply.
(1) See note 5 to the characteristics.
Fig.4 Test circuit for the +12 V supply; not for TDA3845T.
January 1993
10
Philips Semiconductors
Objective specification
Quasi split-sound circuit and AM
demodulator
TDA3845; TDA3845T
APPLICATION INFORMATION
(1) See note 5 to the characteristics.
Fig.5 Application diagram for the +12 V supply; not for TDA3845T.
(1) See note 5 to the characteristics.
Fig.6 Application diagram for the +5 V supply.
January 1993
11
Philips Semiconductors
Objective specification
Quasi split-sound circuit and AM
demodulator
TDA3845; TDA3845T
Fig.7 AM IF filter for standard L.
Fig.8 AM IF filter for standard L-accent.
IF filter proposal for AM sound (see Figs 7 and 8)
With an IF filter in accordance with this proposal, the video buzz suppression on the audio output is better than 50 dB (in
accordance with CCIR 468-3, m = 54%) for the worst case video modulation with 6 kHz sinewave black-to-white.
Note to figures 7 and 8.
Where SC = sound carrier and PC = picture carrier.
January 1993
12
Philips Semiconductors
Objective specification
Quasi split-sound circuit and AM
demodulator
(1) Not for TDA3845T; pin 11 not connected.
Fig.9 Internal pin circuitry.
TDA3845; TDA3845T
January 1993
13
Philips Semiconductors
Objective specification
Quasi split-sound circuit and AM
demodulator
TDA3845; TDA3845T
Picture modulation; 6 kHz sinewave.
Intercarrier signal; sound Channel 1 = 5.5 MHz,
sound Channel 2 = 5.74 MHz.
Fig.10 Response curve of the signal-to-weighted
noise ratio of the demodulated intercarrier
signal.
MLB058
2
handbook, full pagewidth
THD
(%)
1
0
10
10 2
10 3
10 4
Fig.11 Response curve for the total harmonic distortion of the AM signal.
January 1993
14
f (Hz)
10 5
Philips Semiconductors
Objective specification
Quasi split-sound circuit and AM
demodulator
TDA3845; TDA3845T
PACKAGE OUTLINES
DIP16: plastic dual in-line package; 16 leads (300 mil); long body
SOT38-1
ME
seating plane
D
A2
A
A1
L
c
e
Z
b1
w M
(e 1)
b
MH
9
16
pin 1 index
E
1
8
0
5
10 mm
scale
DIMENSIONS (inch dimensions are derived from the original mm dimensions)
UNIT
A
max.
A1
min.
A2
max.
b
b1
c
D (1)
E (1)
e
e1
L
ME
MH
w
Z (1)
max.
mm
4.7
0.51
3.7
1.40
1.14
0.53
0.38
0.32
0.23
21.8
21.4
6.48
6.20
2.54
7.62
3.9
3.4
8.25
7.80
9.5
8.3
0.254
2.2
inches
0.19
0.020
0.15
0.055
0.045
0.021
0.015
0.013
0.009
0.86
0.84
0.26
0.24
0.10
0.30
0.15
0.13
0.32
0.31
0.37
0.33
0.01
0.087
Note
1. Plastic or metal protrusions of 0.25 mm maximum per side are not included.
REFERENCES
OUTLINE
VERSION
IEC
JEDEC
SOT38-1
050G09
MO-001AE
January 1993
EIAJ
EUROPEAN
PROJECTION
ISSUE DATE
92-10-02
95-01-19
15
Philips Semiconductors
Objective specification
Quasi split-sound circuit and AM
demodulator
TDA3845; TDA3845T
SO16: plastic small outline package; 16 leads; body width 3.9 mm
SOT109-1
D
E
A
X
c
y
HE
v M A
Z
16
9
Q
A2
A
(A 3)
A1
pin 1 index
θ
Lp
1
L
8
e
0
detail X
w M
bp
2.5
5 mm
scale
DIMENSIONS (inch dimensions are derived from the original mm dimensions)
UNIT
A
max.
A1
A2
A3
bp
c
D (1)
E (1)
e
HE
L
Lp
Q
v
w
y
Z (1)
mm
1.75
0.25
0.10
1.45
1.25
0.25
0.49
0.36
0.25
0.19
10.0
9.8
4.0
3.8
1.27
6.2
5.8
1.05
1.0
0.4
0.7
0.6
0.25
0.25
0.1
0.7
0.3
0.01
0.019 0.0098 0.39
0.014 0.0075 0.38
0.16
0.15
0.050
0.24
0.23
0.041
0.039
0.016
0.028
0.020
0.01
0.01
0.004
0.028
0.012
inches
0.069
0.0098 0.057
0.0039 0.049
θ
Note
1. Plastic or metal protrusions of 0.15 mm maximum per side are not included.
REFERENCES
OUTLINE
VERSION
IEC
JEDEC
SOT109-1
076E07S
MS-012AC
January 1993
EIAJ
EUROPEAN
PROJECTION
ISSUE DATE
91-08-13
95-01-23
16
o
8
0o
Philips Semiconductors
Objective specification
Quasi split-sound circuit and AM
demodulator
TDA3845; TDA3845T
to the printed-circuit board by screen printing, stencilling or
pressure-syringe dispensing before package placement.
SOLDERING
Introduction
Several techniques exist for reflowing; for example,
thermal conduction by heated belt. Dwell times vary
between 50 and 300 seconds depending on heating
method. Typical reflow temperatures range from
215 to 250 °C.
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.
Preheating is necessary to dry the paste and evaporate
the binding agent. Preheating duration: 45 minutes at
45 °C.
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).
WAVE SOLDERING
Wave soldering techniques can be used for all SO
packages if the following conditions are observed:
DIP
• A double-wave (a turbulent wave with high upward
pressure followed by a smooth laminar wave) soldering
technique should be used.
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 longitudinal axis of the package footprint must be
parallel to the solder flow.
• The package footprint must incorporate solder thieves at
the downstream end.
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 (Tstg 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.
During placement and before soldering, the package must
be fixed with a droplet of adhesive. The adhesive can be
applied by screen printing, pin transfer or syringe
dispensing. The package can be soldered after the
adhesive is cured.
Maximum permissible solder temperature is 260 °C, and
maximum duration of package immersion in solder is
10 seconds, if cooled to less than 150 °C within
6 seconds. Typical dwell time is 4 seconds at 250 °C.
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.
A mildly-activated flux will eliminate the need for removal
of corrosive residues in most applications.
REPAIRING SOLDERED JOINTS
Fix the component by first soldering two diagonallyopposite end leads. Use only a low voltage soldering iron
(less than 24 V) applied to the flat part of the lead. Contact
time must be limited to 10 seconds at up to 300 °C. When
using a dedicated tool, all other leads can be soldered in
one operation within 2 to 5 seconds between
270 and 320 °C.
SO
REFLOW SOLDERING
Reflow soldering techniques are suitable for all SO
packages.
Reflow soldering requires solder paste (a suspension of
fine solder particles, flux and binding agent) to be applied
January 1993
17
Philips Semiconductors
Objective specification
Quasi split-sound circuit and AM
demodulator
TDA3845; TDA3845T
DEFINITIONS
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.
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.
January 1993
18