Chip tda 7294 specifications. Low frequency amplifier on a TDA7384 chip

One of the first I assembled an amplifier on the TDA7294 according to the scheme proposed by the manufacturer.

At the same time, the quality of sound reproduction, especially in the high-frequency region, did not suit me very much. On the Internet, my attention was drawn to the LINCOR article posted on the site datagor.ru. The author's rave reviews about the sound of the UMZCH on the TDA7294, assembled according to the voltage-controlled current source circuit (ITUN), intrigued me. As a result, I assembled the UMZCH according to the following scheme.

The scheme works as follows. The signal from the input IN goes through the pass capacitor C1 to the low-resistance feedback arm R1 R3, which, together with the capacitor C2, forms a low-pass filter that prevents the penetration of interference and high-frequency noise into the audio path. Together with resistor R4, the input circuit creates the first segment of the FOS, whose K is equal to 2.34. Further, if it were not for the current sensor R7, the gain of the second circuit would be given by the ratio R5/R6 and would be equal to 45.5. final Ku would be about 100. However, there is still a current sensor in the circuit, and its signal, summing up with the voltage drop across R6, creates a partial OOS for current. With our circuit ratings Ku=15.5.

Characteristics of the amplifier when operating at a load of 4 ohms:

- Operating frequency range (Hz) - 20-20000;

– Supply voltage (V) – ±30;

– Rated input voltage (V) – 0.6;

- Rated output power (W) - 73;

– Input resistance (kΩ) – 9.4;

– THD at 60W, no more than (%) – 0.01.

A 12V parametric stabilizer is wired on the printed circuit board to power service circuits 9 and 10 of the TDA7294, shown in the figure.

In the “Play!” position, the amplifier is in an unlocked state and is ready to work every second. In the "Mute" position, the input and output stages of the microcircuit are blocked, and its consumption is reduced to the minimum standby currents. Capacitances C11 C12 are doubled compared to stock to provide a longer turn-on delay and prevent speaker clicks even when the power supply capacitors are charged for a long time.

Amplifier details

All resistors, except for R7 and R8, are carbon or metal film 0.125–0.25W, type C1-4, C2-23 or MLT–0.25. Resistor R7 is a 5W wirewound resistor. White SQP resistors in a ceramic case are recommended. R8 - Zobel circuit resistor, carbon, wire or metal film 2W.

C1 - film, the highest quality available, lavsan or polypropylene. K73-17 at 63V will also give a satisfactory result. C2 - ceramic disk or any other type, for example K10-17B. C3 - electrolyte of the highest available quality for a voltage of at least 35 V, C4 C7, C8, C9 - film type K73–17 for 63 V. C5 C6 - electrolytic for a voltage of at least 50 V. C11 C12 - any electrolytic for a voltage of at least 25 V. D1 - any 12 ... 15 V zener diode with a power of at least 0.5 W. Instead of the TDA7294 chip, you can use the TDA7296 ... 7293. In the case of using TDA7296, TDA7295, TDA7293, it is necessary to bite off or bend and not solder the 5th leg of the microcircuit.

Both output terminals of the amplifier are "hot", neither of them is grounded, because. the speaker system is also a feedback link. AC is switched between and .

Below is a board layout with element and wire side views created using the Sprint-Layout_6.0 program.

Amplifiers, the main purpose of which is to amplify the signal in terms of power, are called power amplifiers. As a rule, such amplifiers drive a low-impedance load, such as a loudspeaker.

voltage 3-18 V (nominal - 6 V) . The maximum current consumption is 1.5 A at a quiescent current of 7 mA (at 6 V) and 12 mA (at 18 V). Voltage gain 36.5 dB. at -1 dB 20 Hz - 300 kHz. Rated output power at 10% THD

temporarily turn off the soundtrack. You can double the output power of the TDA7233D when they are turned on according to the scheme shown in fig. 31.42. C7 prevents self-excitation of the device in the area

high frequencies. R3 is selected until an equal amplitude of the output signals is obtained at the outputs of the microcircuits.

Rice. 31.43. KR174UNZ 7

KR174UN31 is intended for use as output low-power household REA.

When the supply voltage changes from

2.1 to 6.6 V with an average current consumption of 7 mA (without an input signal), the voltage gain of the microcircuit varies from 18 to 24 dB.

The coefficient of non-linear distortion at an output power of up to 100 mW is not more than 0.015%, the output noise voltage does not exceed 100 μV. Input microcircuit 35-50 kOhm. load - not less than 8 ohms. Operating frequency range - 20 Hz - 30 kHz, limit - 10 Hz - 100 kHz. The maximum input signal voltage is up to 0.25-0.5 V.

The article is dedicated to lovers of loud and high-quality music. TDA7294 (TDA7293) is a low-frequency amplifier chip manufactured by the French company THOMSON. The circuit contains field-effect transistors, which ensures high sound quality and soft sound. A simple circuit, few additional elements makes the circuit accessible to any radio amateur. A properly assembled amplifier from serviceable parts starts working immediately and does not need to be adjusted.

The audio frequency power amplifier on the TDA 7294 chip differs from other amplifiers of this class:

high output power
wide supply voltage range,
low percentage of harmonic distortion,
"soft sound,
few "mounted" parts,
low cost.

It can be used in amateur radio audio devices, when modifying amplifiers, acoustic systems, audio equipment devices, etc.

The figure below shows typical circuit diagram power amplifier for one channel.

The TDA7294 chip is a powerful operational amplifier whose gain is set by a negative feedback circuit connected between its output (pin 14 of the chip) and the inverted input (pin 2 of the chip). A direct signal is input (pin 3 of the microcircuit). The circuit consists of resistors R1 and capacitor C1. By changing the values of the resistances R1, you can adjust the sensitivity of the amplifier to the parameters of the preamplifier.

Structural diagram of the amplifier on the TDA 7294

Technical characteristics of the TDA7294 chip

Technical characteristics of the TDA7293 chip

Schematic diagram of the amplifier on the TDA7294

To assemble this amplifier, you will need the following parts:

1. Chip TDA7294 (or TDA7293)
2. 0.25 watt resistors
R1 - 680 Ohm
R2, R3, R4 - 22 kOhm
R5 - 10 kOhm
R6 - 47 kOhm
R7 - 15 kOhm
3. Film capacitor, polypropylene:
C1 - 0.74 mkF
4. Electrolytic capacitors:
C2, C3, C4 - 22 mkF 50 volt
C5 - 47 mkF 50 volt
5. Resistor variable dual - 50 kOm

On one chip, you can assemble a mono amplifier. To assemble a stereo amplifier, you need to make two boards. To do this, we multiply all the necessary details by two, except for the dual variable resistor and the PSU. But more on that later.

Amplifier printed circuit board on a TDA 7294 chip

The circuit elements are mounted on a printed circuit board made of one-sided foil fiberglass.

A similar circuit, but a little more elements, mostly capacitors. The turn-on delay circuit is enabled at the “mute” input, pin 10. This is done for a soft, pop-free turn-on of the amplifier.

A microcircuit is installed on the board, in which unused conclusions are removed: 5, 11 and 12. Mount with a wire with a cross section of at least 0.74 mm2. The microcircuit itself must be installed on a radiator with an area of at least 600 cm2. The radiator should not touch the amplifier case as it will have a negative supply voltage. The case itself must be connected to a common wire.

If you use a smaller area of the radiator, you must make forced airflow by placing a fan in the amplifier case. The fan is suitable from a computer, with a voltage of 12 volts. The microcircuit itself should be mounted on a heatsink using heat-conducting paste. Do not connect the radiator to live parts, except for the negative power bus. As mentioned above, the metal plate at the back of the microcircuit is connected to the negative power circuit.

Microcircuits for both channels can be installed on one common radiator.

Power supply for the amplifier.

The power supply is a step-down transformer with two windings with a voltage of 25 volts and a current of at least 5 amperes. The voltage on the windings must be the same and the filter capacitors too. Voltage surge must not be allowed. When applying bipolar power to the amplifier, it must be supplied at the same time!

Diodes in the rectifier are better to put ultra-fast, but in principle, conventional ones like D242-246 for a current of at least 10A are also suitable. It is advisable to solder a capacitor with a capacity of 0.01 microfarads in parallel with each diode. You can also use ready-made diode bridges with the same current parameters.

Filter capacitors C1 and C3 have a capacitance of 22,000 microfarads for a voltage of 50 volts, capacitors C2 and C4 have a capacitance of 0.1 microfarads.

The supply voltage of 35 volts should only be at a load of 8 ohms, if you have a load of 4 ohms, then the supply voltage must be reduced to 27 volts. In this case, the voltage on the secondary windings of the transformer should be 20 volts.

You can use two identical transformers with a power of 240 watts each. One of them is used to obtain a positive voltage, the second - a negative one. The power of two transformers is 480 watts, which is quite suitable for an amplifier with an output power of 2 x 100 watts.

Transformers TBS 024 220-24 can be replaced by any other transformers with a capacity of at least 200 watts each. As mentioned above, nutrition should be the same - transformers must be the same!!! The voltage on the secondary winding of each transformer is from 24 to 29 volts.

Amplifier circuit increased power on two TDA7294 chips in a bridge circuit.

According to this scheme, four microcircuits are needed for the stereo version.

Amplifier Specifications:

Maximum output power at a load of 8 ohms (power supply +/- 25V) - 150 W;
Maximum output power at a load of 16 ohms (power supply +/- 35V) - 170 W;
Load resistance: 8 - 16 Ohm;
Coef. harmonic distortion, at max. power 150 watts, e.g. 25V, load 8 Ohm, frequency 1 kHz - 10%;
Coef. harmonic distortion, at a power of 10-100 watts, e.g. 25V, load 8 Ohm, frequency 1 kHz - 0.01%;
Coef. harmonic distortion, at a power of 10-120 watts, e.g. 35V, load 16 Ohm, frequency 1 kHz - 0.006%;
Frequency range (with non-frequency response 1 db) - 50Hz ... 100kHz.

View of the finished amplifier in a wooden case with a transparent plexiglass top cover.

To operate the amplifier at full power, you need to apply the required signal level to the input of the microcircuit, and this is at least 750mV. If the signal is not enough, then you need to assemble a preamplifier for buildup.

Preamplifier circuit on TDA1524A

Setting up the amplifier

A properly assembled amplifier does not need to be adjusted, but no one guarantees that all the parts are absolutely in good order; when you turn it on for the first time, you need to be careful.

The first power-up is carried out without load and with the input signal source turned off (it is better to short the input with a jumper altogether). It would be nice to include fuses of the order of 1A in the power circuit (both in the "plus" and "minus" between the power source and the amplifier itself). We briefly (~0.5 sec.) apply the supply voltage and make sure that the current consumed from the source is small - the fuses do not burn out. It is convenient if the source has LED indicators - when disconnected from the mains, the LEDs continue to burn for at least 20 seconds: the filter capacitors are discharged for a long time by a small quiescent current of the microcircuit.

If the current consumed by the microcircuit is large (more than 300 mA), then there can be many reasons: short circuit in the installation; poor contact in the "ground" wire from the source; mixed up "plus" and "minus"; the pins of the microcircuit touch the jumper; microcircuit is faulty; capacitors C11, C13 are incorrectly soldered; capacitors C10-C13 are faulty.

After making sure that everything is fine with the quiescent current, safely turn on the power and measure the constant voltage at the output. Its value should not exceed + -0.05 V. A large voltage indicates problems with C3 (less often with C4), or with a microcircuit. There were cases when the "inter-ground" resistor was either poorly soldered, or instead of 3 ohms it had a resistance of 3 kOhm. At the same time, the output was a constant of 10 ... 20 volts. By connecting an AC voltmeter to the output, we make sure that the AC voltage at the output is zero (this is best done with the input closed, or simply with the input cable not connected, otherwise there will be noise at the output). The presence of an alternating voltage at the output indicates problems with the microcircuit, or circuits C7R9, C3R3R4, R10. Unfortunately, often ordinary testers cannot measure the high-frequency voltage that appears during self-excitation (up to 100 kHz), so it is best to use an oscilloscope here.

All! You can enjoy your favorite music!

At present, a wide range of imported low-frequency integrated amplifiers has become available. Their advantages are satisfactory electrical parameters, the ability to select microcircuits with a given output power and supply voltage, stereo or quad performance with the possibility of bridging.
For the manufacture of a structure based on an integral ULF, a minimum of attachments is required. The use of known-good components ensures high repeatability and typically no further tuning is required.
The given typical switching circuits and the main parameters of integrated ULF are designed to facilitate the orientation and selection of the most suitable microcircuit.
For quadraphonic ULF, the parameters in the bridged stereo connection are not indicated.

TDA1010

Supply voltage - 6...24 V
Output power (Un \u003d 14.4 V, THD \u003d 10%):
RL=2 ohm - 6.4W
RL=4 Ohm - 6.2 W
RL=8 ohm - 3.4W
Quiescent current - 31 mA
Switching scheme

TDA1011

Supply voltage - 5.4...20 V
Maximum current consumption - 3 A
Un=16V - 6.5W
Un=12V - 4.2 W
Un=9V - 2.3 W
Un=6B - 1.0W
SOI (P=1 W, RL=4 Ohm) - 0.2%
Quiescent current - 14 mA
Switching scheme

TDA1013

Supply voltage - 10...40 V
Output power (THD=10%) - 4.2 W
SOI (P=2.5 W, RL=8 Ohm) - 0.15%
Switching scheme

TDA1015

Supply voltage - 3.6 ... 18 V
Output power (RL=4 ohm, THD=10%):
Un=12V - 4.2 W
Un=9V - 2.3 W
Un=6B - 1.0W
SOI (P=1 W, RL=4 Ohm) - 0.3%
Quiescent current - 14 mA
Switching scheme

TDA1020

Supply voltage - 6...18 V

RL=2 ohm - 12W
RL=4 Ohm - 7W
RL=8 ohm - 3.5 W
Quiescent current - 30 mA
Switching scheme

TDA1510

Supply voltage - 6...18 V
Maximum current consumption - 4 A
THD=0.5% - 5.5 W
THD=10% - 7.0 W
Quiescent current - 120 mA
Switching scheme

TDA1514

Supply voltage - ±10...±30 V
Maximum current consumption - 6.4 A
Output power:
Un \u003d ± 27.5 V, R \u003d 8 Ohm - 40 W
Un \u003d ± 23 V, R \u003d 4 Ohm - 48 W
Quiescent current - 56 mA
Switching scheme

TDA1515

Supply voltage - 6...18 V
Maximum current consumption - 4 A
RL=2 ohm - 9W
RL=4 ohm - 5.5W
RL=2 ohm - 12W
RL4 Ohm - 7 W
Quiescent current - 75 mA
Switching scheme

TDA1516

Supply voltage - 6...18 V
Maximum current consumption - 4 A
Output power (Un =14.4 V, THD=0.5%):
RL=2 ohm - 7.5W
RL=4 Ohm - 5 W
Output power (Un =14.4 V, THD=10%):
RL=2 ohm - 11W
RL=4 Ohm - 6W
Quiescent current - 30 mA
Switching scheme

TDA1517

Supply voltage - 6...18 V
Maximum current consumption - 2.5 A
Output power (Un=14.4B RL=4 ohm):
THD=0.5% - 5 W
THD=10% - 6 W
Quiescent current - 80 mA
Switching scheme

TDA1518

Supply voltage - 6...18 V
Maximum current consumption - 4 A
Output power (Un =14.4 V, THD=0.5%):
RL=2 ohm - 8.5W
RL=4 Ohm - 5 W
Output power (Un =14.4 V, THD=10%):
RL=2 ohm - 11W
RL=4 Ohm - 6W
Quiescent current - 30 mA
Switching scheme

TDA1519

Supply voltage - 6...17.5 V
Maximum current consumption - 4 A
Output power (Up=14.4 V, THD=0.5%):
RL=2 ohm - 6 W
RL=4 Ohm - 5 W
Output power (Un =14.4 V, THD=10%):
RL=2 ohm - 11W
RL=4 Ohm - 8.5W
Quiescent current - 80 mA
Switching scheme

TDA1551

Supply voltage -6...18 V
THD=0.5% - 5 W
THD=10% - 6 W
Quiescent current - 160 mA
Switching scheme

TDA1521

Supply voltage - ±7.5...±21 V
Output power (Un=±12V, RL=8 ohm):
THD=0.5% - 6 W
THD=10% - 8 W
Quiescent current - 70 mA
Switching scheme

TDA1552

Supply voltage - 6...18 V
Maximum current consumption - 4 A
Output power (Un = 14.4 V, RL = 4 ohms):
THD=0.5% - 17 W
THD=10% - 22 W
Quiescent current - 160 mA
Switching scheme

TDA1553

Supply voltage - 6...18 V
Maximum current consumption - 4 A
Output power (Up=4.4 V, RL=4 Ohm):
THD=0.5% - 17 W
THD=10% - 22 W
Quiescent current - 160 mA
Switching scheme

TDA1554

Supply voltage - 6...18 V
Maximum current consumption - 4 A
THD=0.5% - 5 W
THD=10% - 6 W
Quiescent current - 160 mA
Switching scheme

TDA2004

Output power (Un=14.4V, THD=10%):
RL=4 Ohm - 6.5W
RL=3.2 ohm - 8.0 W
RL=2 ohm - 10W
RL=1.6 ohm - 11W
KHI (Un=14.4V, P=4.0 W, RL=4 Ohm) - 0.2%;
Bandwidth (by level -3 dB) - 35...15000 Hz
Quiescent current -<120 мА
Switching scheme

TDA2005

Dual integrated ULF, designed specifically for use in a car and allowing operation at a low-resistance load (up to 1.6 Ohm).
Supply voltage - 8...18 V
Maximum current consumption - 3.5 A
Output power (Up = 14.4 V, THD = 10%):
RL=4 Ohm - 20W
RL=3.2 Ohm - 22W
SOI (Up = 14.4 V, P = 15 W, RL = 4 Ohm) - 10%
Bandwidth (by level -3 dB) - 40...20000 Hz
Quiescent current -<160 мА
Switching scheme

TDA2006

The pinout matches the pinout of the TDA2030 chip.
Supply voltage - ±6.0...±15 V
Maximum current consumption - 3 A
Output power (Ep=±12V, THD=10%):
at RL=4 Ohm - 12 W
at RL=8 Ohm - 6...8 W SOI (Ep=±12V):
at P=8 W, RL= 4 Ohm - 0.2%
at P=4 W, RL= 8 Ohm - 0.1%
Bandwidth (by level -3 dB) - 20...100000 Hz
Consumption current:
at Р=12 W, RL=4 Ohm - 850 mA
at P=8 W, RL=8 Ohm - 500 mA
Switching scheme

TDA2007

A dual integral ULF with a single in-line arrangement of pins, specially designed for use in television and portable radio receivers.
Supply voltage - +6...+26 V
Quiescent current (Ep=+18 V) - 50...90 mA
Output power (THD=0.5%):
at Ep=+18 V, RL=4 Ohm - 6 W
at En=+22 V, RL=8 Ohm - 8 W
SOI:
at En=+18 V P=3 W, RL=4 Ohm - 0.1%
at En=+22 V, P=3 W, RL=8 Ohm - 0.05%
Bandwidth (by level -3 dB) - 40...80000 Hz
Switching scheme

TDA2008

Integral ULF, designed to operate on a low-resistance load, providing a high output current, very low harmonic content and intermodulation distortion.
Supply voltage - +10...+28 V
Quiescent current (Ep=+18 V) - 65...115 mA
Output power (Ep=+18V, THD=10%):
at RL=4 Ohm - 10...12 W
at RL=8 Ohm - 8 W
THD (Ep= +18 V):
at Р=6 W, RL=4 Ohm - 1%
at P=4 W, RL=8 Ohm - 1%
Maximum consumption current - 3 A
Switching scheme

TDA2009

Dual integrated ULF, designed for use in high-quality music centers.
Supply voltage - +8...+28 V
Quiescent current (Ep=+18 V) - 60...120 mA
Output power (Ep=+24 V, THD=1%):
at RL=4 Ohm - 12.5 W
at RL=8 Ohm - 7 W
Output power (Ep=+18 V, THD=1%):
at RL=4 Ohm - 7 W
at RL=8 Ohm - 4 W
SOI:
at Ep = +24 V, P = 7 W, RL = 4 Ohm - 0.2%
at En= +24 V, P=3.5 W, RL=8 Ohm - 0.1%
at Ep = +18 V, P = 5 W, RL = 4 Ohm - 0.2%
at En= +18 V, P=2.5 W, RL=8 Ohm - 0.1%
Maximum consumption current - 3.5 A
Switching scheme

TDA2030

Integral ULF providing high output current, low harmonics and intermodulation distortion.
Supply voltage - ±6...±18 V
Quiescent current (Ep=±14 V) - 40...60 mA
Output power (Ep=±14 V, THD=0.5%):
at RL=4 Ohm - 12...14 W
at RL=8 Ohm - 8...9 W
SOI (Ep=±12V):
at P=12 W, RL=4 Ohm - 0.5%
at P=8 W, RL=8 Ohm - 0.5%
Bandwidth (by level -3 dB) - 10...140000 Hz
Consumption current:
at P=14 W, RL=4 Ohm - 900 mA
at P=8 W, RL=8 Ohm - 500 mA
Switching scheme

TDA2040

Integral ULF providing high output current, low harmonics and intermodulation distortion.
Supply voltage - ±2.5...±20 V
Quiescent current (Ep=±4.5...±14 V) - mA 30...100 mA
Output power (Ep=±16 V, THD=0.5%):
at RL=4 Ohm - 20...22 W
at RL=8 Ohm - 12 W
SOI (Ep=±12V, P=10W, RL=4 Ohm) - 0.08%
Maximum consumption current - 4 A
Switching scheme

TDA2050

Integral ULF, providing high output power, low harmonics and intermodulation distortion. Designed to work in Hi-Fi stereo complexes and high-end TVs.
Supply voltage - ±4.5...±25 V
Quiescent current (Ep=±4.5...±25 V) - 30...90 mA
Output power (Ep=±18, RL=4 Ohm, THD=0.5%) - 24...28 W
THD (Ep=±18V, P=24W, RL=4 Ohm) - 0.03...0.5%
Bandwidth (by level -3 dB) - 20...80000 Hz
Maximum consumption current - 5 A
Switching scheme

TDA2051

Integral ULF, which has a small number of external elements and provides a low content of harmonics and intermodulation distortion. The output stage operates in class AB, which allows you to get more output power.
Output power:
at Ep=±18 V, RL=4 Ohm, SOI=10% - 40 W
at Ep=±22 V, RL=8 Ohm, SOI=10% - 33 W
Switching scheme

TDA2052

Integral ULF, the output stage of which operates in class AB. Allows a wide range of supply voltages and has a large output current. It is intended for work in television and radio receivers.
Supply voltage - ±6...±25 V
Quiescent current (En = ±22 V) - 70 mA
Output power (Ep = ±22 V, THD = 10%):
at RL=8 Ohm - 22 W
at RL=4 Ohm - 40 W
Output power (En = 22 V, THD = 1%):
at RL=8 Ohm - 17 W
at RL=4 Ohm - 32 W
SOI (with a bandwidth of -3 dB 100 ... 15000 Hz and Pout = 0.1 ... 20 W):
at RL=4 Ohm -<0,7 %
at RL=8 Ohm -<0,5 %
Switching scheme

TDA2611

Integral ULF, designed to work in household equipment.
Supply voltage - 6...35 V
Quiescent current (Ep=18 V) - 25 mA
Maximum consumption current - 1.5 A
Output power (THD=10%): at Ep=18 V, RL=8 Ohm - 4 W
at Ep=12V, RL=8 0m - 1.7 W
at Ep=8.3 V, RL=8 Ohm - 0.65 W
at Ep=20 V, RL=8 Ohm - 6 W
at Ep=25 V, RL=15 Ohm - 5 W
SOI (at Рout=2 W) - 1%
Bandwidth - >15 kHz
Switching scheme

TDA2613

SOI:
(Ep=24 V, RL=8 Ohm, Pout=6 W) - 0.5%
(Ep=24 V, RL=8 Ohm, Рout=8 W) - 10%
Quiescent current (Ep=24 V) - 35 mA
Switching scheme

TDA2614

Integral ULF, designed to work in household equipment (television and radio receivers).
Supply voltage - 15...42 V
Maximum consumption current - 2.2 A
Quiescent current (Ep=24 V) - 35 mA
SOI:
(Ep=24 V, RL=8 Ohm, Pout=6.5 W) - 0.5%
(Ep=24 V, RL=8 Ohm, Pout=8.5 W) - 10%
Bandwidth (by level -3 dB) - 30...20000 Hz
Switching scheme

TDA2615

Dual ULF, designed to work in stereo radios or TVs.
Supply voltage - ±7.5...21 V
Maximum current consumption - 2.2 A
Quiescent current (Ep=7.5...21 V) - 18...70 mA
Output power (Ep=±12 V, RL=8 ohm):
THD=0.5% - 6 W
THD=10% - 8 W
Bandwidth (by level-3 dB and Рout=4 W) - 20...20000 Hz
Switching scheme

TDA2822

Dual ULF, designed to work in portable radio and television receivers.

Quiescent current (Ep=6 V) - 12 mA
Output power (THD=10%, RL=4 ohm):
En \u003d 9V - 1.7 W
En \u003d 6V - 0.65 W
En \u003d 4.5V - 0.32 W
Switching scheme

TDA7052

ULF, designed to work in battery-powered portable audio devices.
Supply voltage - 3...15V
Maximum current consumption - 1.5A
Quiescent current (E p \u003d 6 V) -<8мА
Output power (Ep \u003d 6 V, R L \u003d 8 Ohm, THD \u003d 10%) - 1.2 W

Switching scheme

TDA7053

Dual ULF, designed to work in portable audio devices, but can also be used in any other equipment.
Supply voltage - 6...18 V
Maximum current consumption - 1.5 A
Quiescent current (E p \u003d 6 V, R L \u003d 8 Ohms) -<16 mA
Output power (E p \u003d 6 V, RL \u003d 8 Ohm, THD \u003d 10%) - 1.2 W
SOI (E p \u003d 9 V, R L \u003d 8 Ohm, Pout \u003d 0.1 W) - 0.2%
Operating frequency range - 20...20000 Hz
Switching scheme

TDA2824

Dual ULF, designed to work in portable radio and television receivers
Supply voltage - 3...15 V
Maximum current consumption - 1.5 A
Quiescent current (Ep=6 V) - 12 mA
Output power (THD=10%, RL=4 ohm)
En \u003d 9 V - 1.7 W
En \u003d 6 V - 0.65 W
En \u003d 4.5 V - 0.32 W
SOI (Ep=9 V, RL=8 Ohm, Pout=0.5 W) - 0.2%
Switching scheme

TDA7231

ULF with a wide range of supply voltages, designed to work in portable radios, cassette recorders, etc.
Supply voltage - 1.8 ... 16 V
Quiescent current (Ep=6 V) - 9 mA
Output power (THD=10%):
En=12V, RL=6 Ohm - 1.8 W
En=9B, RL=4 Ohm - 1.6W
Ep=6 V, RL=8 Ohm - 0.4 W
Ep=6 V, RL=4 Ohm - 0.7 W
En \u003d Z V, RL \u003d 4 Ohm - 0.11 W
Ep=3 V, RL=8 Ohm - 0.07 W
SOI (Ep=6 V, RL=8 Ohm, Pout=0.2 W) - 0.3%
Switching scheme

TDA7235

ULF with a wide range of supply voltages, designed to work in portable radio and television receivers, cassette recorders, etc.
Supply voltage - 1.8...24 V
Maximum current consumption - 1.0 A
Quiescent current (Ep=12 V) - 10 mA
Output power (THD=10%):
Ep=9 V, RL=4 Ohm - 1.6 W
Ep=12 V, RL=8 Ohm - 1.8 W
Ep=15 V, RL=16 Ohm - 1.8 W
Ep=20 V, RL=32 Ohm - 1.6 W
SOI (Ep=12V, RL=8 Ohm, Pout=0.5 W) - 1.0%
Switching scheme

TDA7240

Quiescent current (Ep=14.4 V) - 120 mA
RL=4 Ohm - 20W
RL=8 Ohm - 12W
SOI:
(Ep=14.4 V, RL=8 Ohm, Pout=12W) - 0.05%
Switching scheme

TDA7241

Bridge ULF, designed for use in car radios. It has protection against short circuit in the load, as well as against overheating.
Maximum supply voltage - 18 V
Maximum current consumption - 4.5 A
Quiescent current (Ep=14.4 V) - 80 mA
Output power (Ep=14.4 V, THD=10%):
RL=2 ohm - 26W
RL=4 Ohm - 20W
RL=8 Ohm - 12W
SOI:
(Ep=14.4 V, RL=4 Ohm, Pout=12 W) - 0.1%
(Ep=14.4 V, RL=8 Ohm, Pout=6 W) - 0.05%
Level bandwidth -3 dB (RL=4 Ohm, Рout=15 W) - 30...25000 Hz
Switching scheme

TDA1555Q

Supply voltage - 6...18 V
Maximum current consumption - 4 A
Output power (Up = 14.4 V. RL = 4 ohms):
- THD=0.5% - 5 W
- THD=10% - 6 W Quiescent current - 160 mA
Switching scheme

TDA1557Q

Supply voltage - 6...18 V
Maximum current consumption - 4 A
Output power (Up = 14.4 V, RL = 4 ohms):
- THD=0.5% - 17 W
- THD=10% - 22 W
Quiescent current, mA 80
Switching scheme

TDA1556Q

Supply voltage -6...18 V
Maximum current consumption -4 A
Output power: (Up=14.4 V, RL=4 Ohm):
- THD=0.5%, - 17 W
- THD=10% - 22 W
Quiescent current - 160 mA
Switching scheme

TDA1558Q

Supply voltage - 6..18 V
Maximum current consumption - 4 A
Output power (Up=14 V, RL=4 Ohm):
- THD=0.6% - 5 W
- THD=10% - 6 W
Quiescent current - 80 mA
Switching scheme

TDA1561

Supply voltage - 6...18 V
Maximum consumed current - 4 A
Output power (Up=14V, RL=4 Ohm):
- THD=0.5% - 18 W
- THD=10% - 23 W
Quiescent current - 150 mA
Switching scheme

TDA1904

Supply voltage - 4...20 V
Maximum consumed current - 2 A
Output power (RL=4 ohm, THD=10%):
- Up=14 V - 4 W
- Up=12V - 3.1 W
- Up \u003d 9 V - 1.8 W
- Up \u003d 6 V - 0.7 W
SOI (Up=9 V, P<1,2 Вт, RL=4 Ом) - 0,3 %
Quiescent current - 8...18 mA
Switching scheme

TDA1905

Supply voltage - 4...30 V
Maximum current consumption - 2.5 A
Output power (THD=10%)
- Up=24 V (RL=16 Ohm) - 5.3 W
- Up=18V (RL=8 Ohm) - 5.5 W
- Up=14 V (RL=4 Ohm) - 5.5 W
- Up \u003d 9 V (RL \u003d 4 Ohm) - 2.5 W
SOI (Up=14 V, P<3,0 Вт, RL=4 Ом) - 0,1 %
Quiescent current -<35 мА
Switching scheme

TDA1910

Supply voltage - 8...30 V
Maximum consumed current - 3 A
Output power (THD=10%):
- Up=24 V (RL=8 Ohm) - 10 W
- Up=24 V (RL=4 Ohm) - 17.5 W
- Up=18 V (RL=4 Ohm) - 9.5 W
SOI (Up=24 V, P<10,0 Вт, RL=4 Ом) - 0,2 %
Quiescent current -<35 мА
Switching scheme

TDA2003

Supply voltage - 8...18 V
Maximum current consumption - 3.5 A
Output power (Up=14V, THD=10%):
- RL=4.0 Ohm - 6 W
- RL=3.2 Ohm - 7.5 W
- RL=2.0 Ohm - 10 W
- RL=1.6 Ohm - 12 W
SOI (Up=14.4 V, P<4,5 Вт, RL=4 Ом) - 0,15 %
Quiescent current -<50 мА
Switching scheme

TDA7056

ULF, designed to work in portable radio and television receivers.
Supply voltage - 4.5 ... 16 V Maximum current consumption - 1.5 A
Quiescent current (E p \u003d 12 V, R \u003d 16 Ohm) -<16 мА
Output power (E P \u003d 12 V, R L \u003d 16 Ohm, THD \u003d 10%) - 3.4 W
SOI (E P \u003d 12 V, R L \u003d 16 Ohm, Pout \u003d 0.5 W) - 1%
Operating frequency range - 20...20000 Hz
Switching scheme

TDA7245

ULF, designed to work in portable audio devices, but can also be used in any other equipment.
Supply voltage - 12...30 V
Maximum current consumption - 3.0 A
Quiescent current (E p \u003d 28 V) -<35 мА
Output power (THD = 1%):
-E p \u003d 14 V, R L \u003d 4 ohms - 4 W
-E P \u003d 18 V, R L \u003d 8 Ohm - 4 W
Output power (THD = 10%):
-E P \u003d 14 V, R L \u003d 4 ohms - 5 W
-E P \u003d 18 V, R L \u003d 8 Ohm - 5 W
THD,%
-E P \u003d 14 V, R L \u003d 4 Ohm, Pout<3,0 - 0,5 Вт
-E P \u003d 18 V, R L \u003d 8 Ohm, Pout<3,5 - 0,5 Вт
-E P \u003d 22 V, RL \u003d 16 Ohm, Pout<3,0 - 0.4 Вт
Bandwidth by level
-ZdB (E =14 V, PL = 4 Ohm, Pout = 1 W) - 50...40000 Hz

TEA0675

Dual channel Dolby B squelch designed for automotive applications. It contains preamplifiers, an electronically controlled equalizer, an electronic pause detection device for the Automatic Music Search (AMS) scanning mode. Structurally, it is carried out in SDIP24 and SO24 cases.
Supply voltage, 7.6,..12 V
Current consumption, 26...31 mA
Ratio (signal+noise)/signal, 78...84 dB
THD:
at a frequency of 1 kHz, 0.08 ... 0.15%
at a frequency of 10 kHz, 0.15...0.3%
Output impedance, 10 kOhm
Voltage gain, 29...31 dB

TEA0678

Dolby B dual-channel integrated noise suppressor designed for automotive audio applications. Includes preamp stages, electronic equalizer, electronic source switcher, Automatic Music Search (AMS) system.
Available in SDIP32 and SO32 packages.
Current consumption, 28 mA
Preamp Gain (at 1 kHz), 31 dB
Harmonic coefficient
< 0,15 %
at a frequency of 1 kHz with Uout=6 dB,< 0,3 %
Noise voltage, reduced to the input, in the frequency range 20...20000 Hz at Rist=0, 1.4 µV

TEA0679

Two-channel integrated amplifier with Dolby B noise reduction, designed for use in various car audio equipment. Includes pre-amplification stages, an electronically controlled equalizer, an electronic signal source switcher, an Automatic Music Search (AMS) system. The main adjustments of the IC are controlled via the I2C bus
Available in SO32 package.
Supply voltage, 7.6...12 V
Current consumption, 40 mA
Harmonic coefficient
at a frequency of 1 kHz with Uout=0 dB,< 0,15 %
at a frequency of 1 kHz with Uout=10 dB,< 0,3 %
Crosstalk attenuation between channels (Uout = 10 dB, at a frequency of 1 kHz), 63 dB
Signal + noise / noise ratio, 84 dB

TDA0677

Dual preamplifier-equalizer designed for use in car radios. Includes preamplifier and corrector amplifier with electronic time constant switch. It also contains an electronic input switch.
The IC is manufactured in the SOT137A package.
Supply voltage, 7.6.,.12 V
Current consumption, 23...26 mA
Signal+noise/noise ratio, 68...74 dB
Harmonic coefficient:
at a frequency of 1 kHz with Uout = 0 dB, 0.04 ... 0.1%
at a frequency of 10 kHz with Uout = 6 dB, 0.08 ... 0.15%
Output impedance, 80... 100 Ohm
Gain:
at a frequency of 400 Hz, 104...110 dB
at a frequency of 10 kHz, 80..86 dB

TEA6360

Two-channel five-band equalizer, controlled via 12C bus, designed for use in car radios, TVs, music centers.
Manufactured in SOT232 and SOT238 packages.
Supply voltage, 7... 13.2 V
Current consumption, 24.5 mA
Input voltage, 2.1 V
Output voltage, 1 V
Frequency response range -1dB, 0...20000 Hz
Nonlinear distortion factor in the frequency range 20...12500 Hz and output voltage 1.1 V, 0.2...0.5%
Gain, 0.5...0 dB
Operating temperature range, -40...+80 С

TDA1074A

Designed for use in stereo amplifiers as a two-channel tone control (low and medium frequencies) and sound. The microcircuit consists of two pairs of electronic potentiometers with eight inputs and four separate output amplifiers. The adjustment of each potentiometric pair is carried out individually by applying a constant voltage to the corresponding outputs.
The IC is manufactured in SOT102, SOT102-1 packages.
Maximum supply voltage, 23 V
Current consumption (no load), 14...30 mA
Gain, 0 dB
Harmonic coefficient:
at a frequency of 1 kHz with Uout = 30 mV, 0.002%
at a frequency of 1 kHz with Uout = 5 V, 0.015 ... 1%
Noise output voltage in the frequency range 20.. .20000 Hz, 75 µV
Interchannel isolation in the frequency range 20.. .20000 Hz, 80 dB
Maximum power dissipation, 800 mW
Operating temperature range, -30...+80°C

TEA5710

A functionally complete IC that performs the functions of an AM and FM receiver. Contains all the necessary stages: from a high frequency amplifier to an AM / FM detector and a low frequency amplifier. It features high sensitivity and low current consumption. It is used in portable AM / FM receivers, radio timers, radio headphones. The IC is manufactured in the SOT234AG (SOT137A) package.
Supply voltage, 2..,12 V
Consumption current:
in AM mode, 5.6...9.9 mA
in FM mode, 7.3...11.2 mA
Sensitivity:
in AM mode, 1.6 mV/m
in FM mode at a signal-to-noise ratio of 26 dB, 2.0 μV
Harmonic coefficient:
in AM mode, 0.8..2.0%
in FM mode, 0.3...0.8%
Low frequency output voltage, 36...70 mV
Article author: Novik P.E.

Introduction

Amplifier design has always been a challenge. Fortunately, in recent years, many integrated solutions have appeared that make life easier for amateur designers. I also did not complicate the task for myself and chose the most simple, high-quality, with a small number of parts, requiring no tuning and stable operation of the amplifier based on the TDA7294 chip from SGS-THOMSON MICROELECTRONICS. Recently, complaints about this microcircuit have spread on the Internet, which were expressed approximately as follows: "spontaneously excited, with incorrect wiring; it burns, for any reason, etc." Nothing like this. You can burn it only by incorrectly switching it on or shorting it out, and cases of excitation have never been noticed, and not only with me. In addition, it has internal protection against short circuits in the load and protection against overheating. It also has a mute function (used to prevent clicks when turned on) and a standby function (when there is no signal). This IC is a ULF class AB. One of the main features of this microcircuit is the use of field-effect transistors in the preliminary and output amplification stages. Its advantages include high output power (up to 100 W at a load of 4 ohms), the ability to work in a wide range of supply voltages, high technical characteristics (low distortion, low noise, wide operating frequency range, etc.), the minimum required external components and low cost

Main characteristics of TDA7294:

Parameter	Conditions	Minimum	Typical	Maximum	Units
Supply voltage		±10		±40	IN
Frequency response	3db signal Output power 1W	20-20000			Hz
Long Term Output Power (RMS)	harmonic distortion 0.5%: Up \u003d ± 35 V, Rn \u003d 8 Ohm Up \u003d ± 31 V, Rn \u003d 6 Ohm Up \u003d ± 27 V, Rn \u003d 4 Ohm	60 60 60	70 70 70		Tue
Peak Musical Output Power (RMS), duration 1 sec.	harmonic factor 10%: Up \u003d ± 38 V, Rn \u003d 8 Ohm Up \u003d ± 33 V, Rn \u003d 6 Ohm Up \u003d ± 29 V, Rn \u003d 4 Ohm		100 100 100		Tue
General harmonic distortion	Po = 5W; 1kHz Po = 0.1-50W; 20-20000Hz		0,005	0,1	%
General harmonic distortion	Up \u003d ± 27 V, Rn \u003d 4 Ohm: Po = 5W; 1kHz Po = 0.1-50W; 20-20000Hz		0,01		%
Protection operation temperature		145			0C
Quiescent current		20	30	60	mA
Input impedance		100			kOhm
Voltage gain		24	30	40	dB
Peak output current		10			A
Working temperature range		0		70	0C
Case thermal resistance				1,5	0 C/W

(PDF format).

There are a lot of schemes for switching on this microcircuit, I will consider the simplest one:

Typical switching circuit:

Item List:

Position	Name	Type	Quantity
C1	0.47uF	K73-17	1
C2, C4, C5, C10	22uF x 50V	K50-35	4
C3	100 pF		1
C6, C7	220uF x 50V	K50-35	2
C8, C9	0.1uF	K73-17	2
DA1	TDA7294		1
R1	680 ohm	MLT-0.25	1
R2…R4	22 kOhm	MLT-0.25	3
R5	10 kOhm	MLT-0.25	1
R6	47 kOhm	MLT-0.25	1
R7	15 kOhm	MLT-0.25	1

The microcircuit must be installed on a radiator with an area of \u003e 600 cm 2. Be careful, on the microcircuit case there is not a common, but a power minus! When installing a chip on a heatsink, it is better to use thermal paste. It is advisable to lay a dielectric between the microcircuit and the radiator (mica, for example). For the first time, I did not attach any importance to this, I thought, why would I be so scared to close the radiator to the case, but in the process of debugging the design, the tweezers that accidentally fell from the table shorted the radiator to the case. The explosion was great! Chips just smashed to pieces! In general, I got off with a slight fright and $ 10 :). On the board with an amplifier, it is also desirable to supply powerful electrolytes of 10000 microns x 50V, so that at power peaks the wires from the power supply do not give voltage drops. In general, the larger the capacitance of the capacitors on the power supply, the better, as they say, "you can't spoil the porridge with oil." Capacitor C3 can be removed (or not installed), I did just that. As it turned out, it was precisely because of him that when the volume control (a simple variable resistor) was turned on in front of the amplifier, an RC circuit was obtained, which mowed high frequencies when the volume was increased, but in general it is needed to prevent excitation of the amplifier when ultrasound is applied to the input. Instead of C6, C7, I put on the board 10000mk x 50v, C8, C9, you can put any close denomination - these are power filters, they can be in the power supply, or you can solder them by surface mounting, which I did.

Pay:

I personally don't really like to use ready-made boards, for one simple reason - it's hard to find exactly the same size elements. But in an amplifier, the wiring can greatly affect the sound quality, so it's up to you which board to choose. Since I assembled the amplifier immediately for 5-6 channels, respectively, the board immediately for 3 channels:

In vector format (Corel Draw 12)
Amplifier power supply, low-pass filter, etc.

power unit

For some reason, the power supply of the amplifier raises many questions. In fact, right here, everything is quite simple. The transformer, diode bridge and capacitors are the main elements of the power supply. This is enough to assemble the simplest power supply.

To power the power amplifier, voltage stabilization is unimportant, but the capacitances of the capacitors for power supply are important, the more, the better. The thickness of the wires from the power supply to the amplifier is also important.

My power supply is implemented as follows:

The +-15V supply is designed to power the operational amplifiers in the preliminary stages of the amplifier. You can do without additional windings and diode bridges by powering the stabilization module from 40V, but the stabilizer will have to dampen a very large voltage drop, which will lead to significant heating of the stabilizer microcircuits. Stabilizer microcircuits 7805/7905 are imported analogues of our KREN.

Variations of blocks A1 and A2 are possible:

Block A1 is a power supply noise suppression filter.

Block A2 - a block of stabilized voltages + -15V. The first alternative is easy to implement, for powering low-current sources, the second is a high-quality stabilizer, but requires an accurate selection of components (resistors), otherwise you will get a skew of the "+" and "-" shoulders, which will then give a skew of zero on operational amplifiers.

Transformer

The power supply transformer for a 100W stereo amplifier should be approximately 200W. Since I was making a 5-channel amplifier, I needed a more powerful transformer. But I didn’t have to pump out all 100W, and all channels cannot simultaneously take power. I came across a TESLA transformer on the market (below in the photo) watt commercial for 250 - 4 windings with 1.5 mm wire at 17V and 4 windings at 6.3V. By connecting them in series, I got the necessary voltages, although I had to rewind two windings at 17V a little in order to get the total voltage of the two windings ~ 27-30V, since the windings were on top - it was not much work.

A great thing is a toroidal transformer, these are used to power halogens in lamps, there are a lot of them in markets and stores. If structurally two such transformers are placed one on top of the other, the radiation will be mutually compensated, which will reduce interference on the amplifier elements. The trouble is that they have one 12V winding. In our radio market, you can make such a transformer to order, but this pleasure will be well worth it. In principle, you can buy 2 transformers for 100-150W and rewind the secondary windings, the number of turns of the secondary winding will need to be increased by about 2-2.4 times.

Diodes / diode bridges

You can buy imported diode assemblies with a current of 8-12A, this greatly simplifies the design. I used KD 213 pulse diodes, and made a separate bridge for each arm to give a current margin for the diodes. When turned on, powerful capacitors are charged, the current surge is very significant, at a voltage of 40 V and a capacitance of 10,000 μF, the charging current of such a capacitor is ~ 10 A, respectively, along two arms 20A. In this case, the transformer and rectifier diodes briefly operate in short circuit mode. The breakdown of diodes by current will give unpleasant consequences. The diodes were installed on the radiators, but I did not find any heating of the diodes themselves - the radiators were cold. To eliminate power supply interference, it is recommended to install a capacitor ~ 0.33 μF type K73-17 in parallel with each diode in the bridge. I really didn't do it. In the + -15V circuit, you can use bridges of the KTs405 type, for a current of 1-2A.

Design

Finished construction.

The most boring occupation is the body. As a case, I took an old slim case from a personal computer. I had to shorten it a little in depth, although it was not easy. I think that the case turned out to be successful - the power supply is located in a separate compartment and you can put 3 more channels of amplification into the case freely.

After field tests, it turned out that it is not out of place to put the fans on the radiators, despite the fact that the radiators are very impressive in size. I had to make holes in the case from the bottom and top, for good ventilation. The fans are connected through a 100Ω 1W trimmer at the lowest speed (see the following figure).

Amplifier block

Chips are on mica and thermal paste, the screws also need to be isolated. The heatsinks and the board are screwed to the case through dielectric racks.

Input circuits

I really wanted not to do this, only in the hope that this is all temporary ....

After hanging these guts, a small rumble appeared in the speakers, apparently something was wrong with the "ground". I dream of the day when I will throw it all out of the amplifier and use it only as a power amplifier.

Adder board, low-pass filter, phase shifter

Regulation block

Result

The back turned out more beautiful, even though you turn it booty forward ... :)

Construction cost.

TDA 7294	$25,00
capacitors (powerful electrolytes)	$15,00
capacitors (other)	$15,00
connectors	$8,00
power button	$1,00
diodes	$0,50
transformer	$10,50
radiators with coolers	$40,00
resistors	$3,00
variable resistors + knobs	$10,00
biscuit	$5,00
frame	$5,00
operational amplifiers	$4,00
Surge Protectors	$2,00
Total	$144,00

Yes, something came out cheap. Most likely, I didn’t take into account something, I just bought, as always, a lot more, because I still had to experiment, and I burned 2 microcircuits and blew up one powerful electrolyte (I didn’t take all this into account). This is the calculation of the amplifier for 5 channels. As you can see, the heatsinks turned out to be very expensive, I used inexpensive, but massive coolers for processors, at that time (a year and a half ago) they were very good for cooling processors. If you consider that an entry-level receiver can be bought for $240, then you might wonder if you need it :), though there is a lower quality amplifier there. Amplifiers of this class cost about $500.

List of radio elements

Designation	Type	Denomination	Quantity	Note	My notepad
DA1	Audio amplifier	TDA7294	1		To notepad
C1	Capacitor	0.47uF	1	K73-17	To notepad
C2, C4, C5, C10		22uF x 50V	4	K50-35	To notepad
C3	Capacitor	100 pF	1		To notepad
C6, C7	electrolytic capacitor	220uF x 50V	2	K50-35	To notepad
C8, C9	Capacitor	0.1uF	2	K73-17	To notepad
R1	Resistor	680 ohm	1	MLT-0.25	To notepad
R2-R4	Resistor	22 kOhm	3	MLT-0.25	To notepad
R5	Resistor