Datasheet TDA3845T Datasheet (Philips)

INTEGRATED CIRCUITS

DATA SH EET

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

TDA3845; TDA3845T

demodulator

FEATURES

• Power supply from 5 V (200 mW) to 8 V source also an
alternative 12 V source (12 V not for TDA3845T)

• Gain controlled wideband IF amplifier (AC coupled with
three stages)

• High precision internal 90° phase shifter for quadrature
demodulator

• Amplitude detector for gain control which operates as a
peak detector for FM sound and as a mean level
detector for AM sound (switchable)

• In-phase wideband synchronous demodulator for AM
detection

QUICK REFERENCE DATA

SYMBOL PARAMETER MIN. TYP. MAX. UNIT

positive supply voltage

V

P1

V

P2

I

P

V

1-16(RMS)

pin 14 4.5 5.0 8.8 V

pin 11 (not for TDA3845T) 10.8 12.0 13.2 V
supply current − 40 − mA
minimum IF input voltage (RMS value) − 70 100 µV
IF control range 60 63 − dB

V

12-13(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

V

6-13(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 − 12%
T

amb

operating ambient temperature 0 − +70 °C

• Stabilizer circuit for ripple rejection and constant output
signals

• ESD protection for all pins

• Suitable for all FM standards and L as well as L-accent

standard

• NICAM compatible.

GENERAL DESCRIPTION

The TDA3845 is a quasi split-sound IF circuit which is
designed to provide high performance television FM/AM
sound.

ORDERING INFORMATION

EXTENDED

TYPE NUMBER

PINS PIN POSITION MATERIAL CODE

PACKAGE

TDA3845 16 DIL plastic SOT38
TDA3845T 16 SO16 plastic SOT109A

Note

1. SOT38-1; 1996 November 28.

2. SOT109-1; 1996 November 28.

January 1993 2

(1)

(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

(1) not for TDA3845T, pin 11 not connected.

Fig.2 Pin configuration.

TDA3845; TDA3845T

PINNING

SYMBOL 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
LC

REF

LC

REF

n.c. 10 not connected
V

P2

ICO 12 intercarrier output
GND 13 ground (0 V)
V

P1

n.c. 15 not connected
IF1 16 IF amplifier input 1

Note to Pinning

1. Not for TDA3845T, pin 11 not connected.

8 LC reference circuit for the picture

carrier

9 LC reference circuit for the picture

carrier

11 positive supply voltage 2

(+12 V); note 1

14 positive supply voltage 1 (+5 V)

LIMITING VALUES

In accordance with the Absolute Maximum Rating System (IEC134)

SYMBOL PARAMETER MIN. MAX. UNIT

supply voltage

V

P1

V

P2

T

amb

T

stg

pin 14 4.5 8.8 V

pin 11 (not for TDA3845T) 10.8 13.2 V
operating ambient temperature 0 +70 °C
storage temperature −25 +125 °C

January 1993 4

Philips Semiconductors Objective specification

Quasi split-sound circuit and AM

TDA3845; TDA3845T

demodulator

CHARACTERISTICS

= 5 V (note 11); T

V

P1

SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT

Supply

supply voltage

V

P1

V

P2

I

tot

pin 14 4.5 5.0 8.8 V
pin 11 (not for TDA3845T) 10.8 12.0 13.2 V

total supply current − 40 48 mA

IF amplifier

R

1-16

C

1-16

V

1-16(RMS)

input resistance − 2 − kΩ
input capacitance − 2.5 − pF
minimum IF input voltage

(RMS value)

V

1-16(RMS)

maximum IF input voltage

(RMS value)
∆G gain control range 60 63 − dB
G
B
V

v3-16
IF
1-16

gain control voltage range 1.5 − 3.0 V
IF bandwidth −3 dB 50 70 − MHz
DC potential − 1.7 − V

Intercarrier mode (FM mode; standard B/G) notes 3, 4 and 5

Reference amplifier
V

8-9(p-p)

picture carrier amplitude
(peak-to-peak value)

R

8-9

V

8-9

operating resistance − 4 − kΩ

DC potential − 3.9 − V
Intercarrier mixer and output stage
V

12(RMS)

output signal (RMS value)

at 5.5 MHz 70 100 − mV
at 5.74 MHz 32 45 − mV

B

12

intercarrier bandwidth

at −1 dB − 8 − MHz
at −3 dB − 9 − MHz

residual video AM on intercarrier

signal
R

12

V

12

I

12(peak)

output resistance − 30 −Ω

DC potential − 1.8 − V

permissible AC output current

(peak value)
I

12

permissible DC output current −−−2mA

= 25 °C; all measurements are referenced to ground (pin 13); unless otherwise specified.

amb

note 1 − 70 100 µV

note 2 70 100 − mV

− 270 − mV

note 6 − 310%

note 7 −−±0.7 mA

January 1993 5

Philips Semiconductors Objective specification

Quasi split-sound circuit and AM

TDA3845; TDA3845T

demodulator

SYMBOL 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)
(S +W)/W 250 kHz square wave

(black-to-white modulation)

AM mode (standard L) note 9

S/N weighted in accordance with CCIR 468-3
V

6(RMS)

B

AF

AF output signal (RMS value) 440 550 660 mV

AF bandwidth −3 dB; note 12 0.02 − 120 kHz
THD total harmonic distortion − 12%
(S +W)/W signal-to-weighted-noise ratio note 10 50 56 − dB
R

6

V

6

I

6(peak)

output resistance − 200 −Ω

DC potential − 1.8 − V

permissible AC output current

note 7 −−±0.3 mA

(peak value)
I

6

permissible DC output current −−−1mA

Standard switch (note 4)

V

7

V

7

V

7

I

7

peak signal AGC (FM mode) VP1 used 1.8 − V

or switch open-circuit VP2 used 1.8 − 5.5 V
mean signal AGC (AM mode) −−0.8 V
switch current

at 0 V −−−200 µA

at V

P1

at V

P2

via a 2.2 kΩ series resistor −−2.5 mA

Ripple rejection (note 13)

AM/AF signal
αRR voltage ripple on V

/

P

voltage ripple on output signal

FM phase noise
∆f(RMS) intercarrier signal − 10 20 Hz

53/51 57/55 − dB

50/44 56/50 − dB

P1

V

−−10 µA

30 40 − dB

January 1993 6

Philips Semiconductors Objective specification

Quasi split-sound circuit and AM

TDA3845; TDA3845T

demodulator

SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT

AM mode (standard L) note 9

S/N weighted in accordance with CCIR 468-3
V

6(RMS)

B

AF

THD total harmonic distortion − 12%
(S +W)/W signal-to-weighted-noise ratio note 10 50 56 − dB
R

6

V

6

I

6(peak)

I

6

Standard switch (note 4)

V

7

V

7

V

7

I

7

Ripple rejection (note 13)

AM/AF signal
αRR voltage ripple on V

FM phase noise
∆f(RMS) intercarrier signal − 10 20 Hz

AF output signal (RMS value) 440 550 660 mV
AF bandwidth −3 dB; note 12 0.02 − 120 kHz

output resistance − 200 −Ω
DC potential − 1.8 − V
permissible AC output current

note 7 −−±0.3 mA

(peak value)
permissible DC output current −−−1mA

peak signal AGC (FM mode) VP1 used 1.8 − V

P1

V

or switch open-circuit VP2 used 1.8 − 5.5 V
mean signal AGC (AM mode) −−0.8 V
switch current

at 0 V −−−200 µA

at V

at V

P1
P2

via a 2.2 kΩ series resistor −−2.5 mA

/

P

−−10 µA

30 40 − dB

voltage ripple on output signal

January 1993 7

Philips Semiconductors Objective specification

Quasi split-sound circuit and AM

TDA3845; TDA3845T

demodulator

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); V
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:

CSCPfPCfSC⁄()

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.

2

C

–=

P

= 10 mV (RMS). Transmitter mode: DSB.

1-16

January 1993 8

Philips Semiconductors Objective specification

Quasi split-sound circuit and AM

TDA3845; TDA3845T

demodulator

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) V

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.

= 10 mV (RMS).

1-16

January 1993 9

Philips Semiconductors Objective specification

Quasi split-sound circuit and AM
demodulator

(1) See note 5 to the characteristics.

TDA3845; TDA3845T

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

APPLICATION INFORMATION

TDA3845; TDA3845T

(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.

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.

Fig.8 AM IF filter for standard L-accent.

January 1993 12

Philips Semiconductors Objective specification

Quasi split-sound circuit and AM
demodulator

TDA3845; TDA3845T

January 1993 13

Fig.9 Internal pin circuitry.

(1) Not for TDA3845T; pin 11 not connected.

Philips Semiconductors Objective specification

Quasi split-sound circuit and AM
demodulator

Picture modulation; 6 kHz sinewave.
Intercarrier signal; sound Channel 1 = 5.5 MHz,

sound Channel 2 = 5.74 MHz.

TDA3845; TDA3845T

Fig.10 Response curve of the signal-to-weighted

noise ratio of the demodulated intercarrier
signal.

handbook, full pagewidth

2

THD

(%)

1

MLB058

0

10

2

10

10

Fig.11 Response curve for the total harmonic distortion of the AM signal.

January 1993 14

3

4

10

f (Hz)

5

10

Philips Semiconductors Objective specification

Quasi split-sound circuit and AM
demodulator

PACKAGE OUTLINES

DIP16: plastic dual in-line package; 16 leads (300 mil); long body

D

seating plane

L

Z

16

e

b

b

1

9

A

1

w M

TDA3845; TDA3845T

SOT38-1

M

E

A

2

A

c

(e )

1

M

H

pin 1 index

1

0 5 10 mm

DIMENSIONS (inch dimensions are derived from the original mm dimensions)

A

UNIT

mm

inches

Note

1. Plastic or metal protrusions of 0.25 mm maximum per side are not included.

A

max.

4.7 0.51 3.7

OUTLINE
VERSION

SOT38-1

min.

A

1 2

max.

0.15

IEC JEDEC EIAJ

050G09 MO-001AE

b

1.40

1.14

0.055

0.045

b

0.53

0.38

0.021

0.015

1

cEe M

0.32

0.23

0.013

0.009

REFERENCES

D

21.8

21.4

0.86

0.84

8

scale

(1) (1)

6.48

6.20

0.26

0.24

E

(1)

Z

e

0.30

1

0.15

0.13

M

L

3.9

3.4

E

8.25

7.80

0.32

0.31

EUROPEAN

PROJECTION

9.5

8.3

0.37

0.33

w

H

0.2542.54 7.62

0.010.100.0200.19

ISSUE DATE

92-10-02
95-01-19

max.

2.2

0.087

January 1993 15

Philips Semiconductors Objective specification

Quasi split-sound circuit and AM
demodulator

SO16: plastic small outline package; 16 leads; body width 3.9 mm

D

c

y

Z

16

9

TDA3845; TDA3845T

SOT109-1

E

H

E

A

X

v M

A

pin 1 index

1

e

0 2.5 5 mm

DIMENSIONS (inch dimensions are derived from the original mm dimensions)

mm

A

max.

1.75

0.069

A1A2A

0.25

1.45

0.10

1.25

0.010

0.057

0.004

0.049

0.25

0.01

b

3

p

0.49

0.25

0.36

0.19

0.0100

0.019

0.0075

0.014

UNIT

inches

Note

1. Plastic or metal protrusions of 0.15 mm maximum per side are not included.

(1)E(1) (1)

cD

10.0

9.8

0.39

0.38

8

b

p

scale

eHELLpQZywv θ

4.0

1.27

3.8

0.16

0.050

0.15

w M

6.2

5.8

0.244

0.228

A

2

1.05

0.041

Q

A

1

detail X

1.0

0.7

0.4

0.6

0.028

0.039

0.020

0.016

(A )

L

p

L

0.25 0.1

0.25

0.01

0.01 0.004

A

3

θ

0.7

0.3

0.028

0.012

o

8

o

0

OUTLINE
VERSION

SOT109-1

IEC JEDEC EIAJ

076E07S MS-012AC

REFERENCES

January 1993 16

EUROPEAN

PROJECTION

ISSUE DATE

95-01-23
97-05-22

Philips Semiconductors Objective specification

Quasi split-sound circuit and AM
demodulator

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

“IC Package Databook”

our

DIP

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
printed-circuit board has been pre-heated, forced cooling
may be necessary immediately after soldering to keep the
temperature within the permissible limit.

R

EPAIRING 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.

(order code 9398 652 90011).

). If the

stg max

TDA3845; TDA3845T

to the printed-circuit board by screen printing, stencilling or
pressure-syringe dispensing before package placement.

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.

Preheating is necessary to dry the paste and evaporate
the binding agent. Preheating duration: 45 minutes at
45 °C.

W

AVE SOLDERING

Wave soldering techniques can be used for all SO
packages if the following conditions are observed:

• A double-wave (a turbulent wave with high upward
pressure followed by a smooth laminar wave) soldering
technique should be used.

• 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.

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.

A mildly-activated flux will eliminate the need for removal
of corrosive residues in most applications.

EPAIRING SOLDERED JOINTS

R

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

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.

Philips Semiconductors Objective specification

Quasi split-sound circuit and AM

TDA3845; TDA3845T

demodulator

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