Fig. 1 - Layout of the Printed Circuit board

56W RMS Hi-FI Amplifier using LM3875 Integrated Circuit + PCB

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High-performance Hi-FI Audio Amplifier, capable of producing excellent audio quality, using the LM3875 integrated circuit.

The LM3875 is a high-performance power audio amplifier capable of delivering 56W of continuous power at 8Ω load with 0.1% THD + N from 20Hz to 20KHz.

The LM3875 features an instantaneous temperature protection circuit with auto peak (° Ke) (SPiKe), which puts it in a class above discrete and hybrid amplifiers, inherently providing a safe operating area (SOA) dynamically protected by the circuits.

SPiKe protection, this means that the entire circuit is completely protected at the output against over-voltage, under-voltage, overloads caused by shorted outputs, thermal leaks, and instantaneous temperature spikes.

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The LM3875 maintains an excellent signal-to-noise transient rate above 95dB (min), with a typical low noise level of 2.0μV. It displays extremely low THD + N values ​​of 0.06% at the rated output into the rated and provides excellent linearity with a typical IMD (SMPTE) rating of 0.004%.

Features of LM3875

• 56W continuous average output power at 8Ω
• 100W instantaneous peak output capacity
• Signal-to-noise ratio> 95dB (min)
• Short-circuit protection to the ground or, to supplies via internal current limiting circuit
• Output overvoltage protection against inductive load transients
• Provides protection against under-voltage, not allowing internal polarization when | V + | + | V− | ≤ 12V, thus eliminating the activation transients are deactivated
• 11 Lead PFM Package
• Wide supply voltage range: | V + | + | V− | = 20V to 84V
• Total harmonic distortion (THD) less than 0.03% in the frequency range of 20Hz to 20kHz

Power Supply Circuit

The power supply provided by a transformer AC,  which can be elaborated through a 28-0-28Vac,  with 5 Ampers current, which after going through the rectification, will be delivered in the supply range around +/- 40Vdc.

As we saw in the characteristics of the LM3875 above, it has a wide range of supply voltage, which we can use a lower voltage or higher voltage source, we can do with what we have on our bench.

In Figure 2 below, we have the schematic diagram of the 56W Hi-End Amplifier with the LM3875 CI.

Fig. 2 - Schematic diagram of 56W RMS Hi-End Amplifier with LM3875 IC

Component List

Printed Circuit Board

The layout of the Printed Circuit Board is shown in Figure 1, and we have all the necessary files for you to be able to print your PCI, with the GERBER files, PDF Layout, PNG, all with a direct link for you to download and assemble yours.

Downloadable files

Files: Gerber, Layout in PDF, PNG, for download. Direct link: Click Here

I hope you enjoyed it!!!

Figure 1 - PCB Hi-Fi 30W Power Amplifier LM1875

The amplifier presented, is a hi-fi amplifier based on the Integrated Circuit LM1875, which is a monolithic power amplifier offering very low distortion and high-quality performance for consumer audio applications.

General Description

The LM1875 delivers 20 watts into a 4Ω or 8Ω load on ±25V supplies. Using an 8Ω load and ±30V supplies, over 30 watts of power may be delivered.

The LM1875 is a wide power amplifier with very low distortion and high-quality efficiency for audio applications, the amplifier is designed to operate with a minimum of external components.

Device overload protection consists of both internal current limit and thermal shutdown.

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The LM1875 design takes advantage of advanced circuit techniques and processing to achieve extremely low distortion levels even at high output power levels.

Other outstanding features include high gain, fast slew rate, and wide power bandwidth, large output voltage swing, high current capability, and a very wide supply range. The amplifier is internally compensated and stable for gains of 10 or greater.

Features

• Up to 30 Watts Output Power
• AVO Typically 90 dB
• Low Distortion: 0.015%, 1 kHz, 20 W
• Wide Power Bandwidth: 70 kHz
• Protection for AC and DC Short Circuits to Ground
• Thermal Protection with Parole Circuit
• High Current Capability: 4A
• Wide Supply Range 16V-60V
• Internal Output Protection Diodes
• 94 dB Ripple Rejection
• Plastic Power Package TO-220

Applications

• High-Performance Audio Systems
• Bridge Amplifiers
•  Stereo Phonographs
• Servo Amplifiers
• Instrument Systems

The connection diagram or if you prefer, the pinout of the LM1875 is shown in Figure 2 below.

Figure 2 - Pinout LM1875 Audio Amplifier

 

Figure 3 - Schematic Audio Power Amplifier IC LM1875

Power Dissipation and Heat Sink

The LM1875 must always be operated with a heat sink, even when it is not required to drive a load. Assumes the use of a heat sink having a thermal resistance of 1°C/W and no insulator with an ambient temperature of 25°C. 

Because the output limiting circuitry has a negative temperature coefficient, the maximum output power delivered to a 4Ω load may be slightly reduced when the tab temperature exceeds 55°C.

Component List

• U1 ......... LM1875 Integrated Circuit.
• R1 ......... 1MΩ 1/8w Resistor (brown, black, yellow, gold)
• R2 ......... 22KΩ 1/8w Resistor (red, red, orange, gold)
• R3 ......... 1KΩ 1/8w Resistor (brown, black, red, gold)
• R4 ......... 20KΩ 1/8w Resistor (red, black, orange, gold)
• R5 ........  1Ω 1/8w Resistor (brown, black,  gold)
• C1 ......... 2.2µF Polyester capacitor
• C2 .....… 25V  22µF Electrolytic capacitor
• C3, C4 ... 0.1uF Ceramic capacitor
• C5 .......... 0.22uF Ceramic capacitor
• C6, C7 ... 70V  100µF Electrolytic capacitor
• P1, P3 .... Screw Terminal Block: 2-Pin, 5 mm
• P2 .......... Screw Terminal Block: 3-Pin, 5 mm
• Others .... printed circuit board, heat sink, box, tin, wires, etc.
  
  

Printed Circuit Board

The layout of the Printed Circuit Board is shown in Figure 1, and we have all the necessary files for you to be able to print your PCI, with the GERBER files, PDF Layout, JPG. All with a direct link for you to download and assemble yours.

Downloadable files

Files: Gerber, Layout in PDF, PNG, to download. Direct link: Click Here!

Fig 1 - Hi-Fi 32W Audio Amplifier PCB

• High Output Power
• 50W Music Power IEC 268.3 Rules
• High Operating Supply Voltage - 50V
• Single or Split Supply Operations
• Very Low Distortion
• Short Circuit Protection  - OUT to GND
• Thermal Shutdown
  
  

Description

The TDA 2050 is a monolithic integrated circuit intended for use as an audio class AB audio amplifier. Thanks to its high power capability the TDA2050 is able to provide up to 35W true RMS power how showed below:

The high power and very low harmonic and crossover distortion THD = 0.05% typ, @ VS = ±22V, PO = 0.1 to 15W, RL=8ohm, f = 100Hz to 15KHz) make the device most suitable for both HiFi and high class TV sets.

The schematic diagram is shown in Figure 2 below, it is a simple circuit to assemble, and to use it in Stereo, we can assemble two of the same, one for each channel.

Fig. 2 - Schematic diagram Hi Fi 32W Audio Amplifier - TDA2050

Components List

The recommended values of the external components are those shown below. Different values can be used, however, to better performance, you must use these values.

Parts List

• U1 ............................ Integrated Circuit TDA2050 Audio Power Amplifier
• R1, R2, R3, R5 ........ 22KΩ 1/4w Resistor
• R4 ............................ 680Ω 1/4w Resistor
• R6 ............................ 2.2Ω 1/4w Resistor
• C1 ............................ 2.2uF /25V Electrolytic capacitor
• C2 ............................ 100uF /25V Electrolytic capacitor
• C3, C7 ..................... 1000uF /50V Electrolytic capacitor
• C4 ............................ 22uF /25V Electrolytic capacitor
• C5 ............................ 100nF  Polyester Capacitor
• C6 ............................. 0.47uF Polyester Capacitor
• RP1 .......................... 47KΩ Potentiometer
• P1, P2, P3 ................ Screw Terminal Block: 2-Pin, 5 mm
• Miscellaneous .......... Heatsink, screw, solder, etc.

Printed Circuit Board

We're providing the Printed Circuit Board, we leave the GERBER, PDF, LAYOUT files, to be downloaded at the link below.

Downloadable files

Files: Gerber, Layout in PDF, PNG, for download. Direct link: Click Here!

Step 1 - Transient Filter

Is through that stage that the voltage coming from your network, whether 110 or 220V AC should enter.

Transient Filter

This voltage goes through basic protection, the fuse, that if some step ahead short, the fuse opens, avoiding to burst everything ahead, and in the same line, we have the NTC (Negative Temperature Coefficient), It's a surge current limiter, in series with the electric circuit,

In it the value of ohmic resistance decreases as its temperature rises, its initial resistance is approximately 15 Ohms, which we can understand by the Ohms' law, the advantages one has in using it in series after the power supply switches it on lowers its resistance to approximately 0.5 Ohms.

EMI filters also exist, these are used to avoid high-frequency noise and a huge amount of harmonics generated by the switches that can propagate through the electrical network and cause interference in nearby electronic equipment.

Step 2 - Primary Rectification

Primary Rectification

Step 3 - Filtration

Filtration

Step 4 - Power Switches

Power Switches

Step 5 - Output Transformer

Output Transformer

Step 6 - Fast Rectifier

Fast Rectifier

With the voltage generated by high-frequency switches, a diode is needed to meet this demand, so we have the high-speed diodes called SCHOTTKY DIODES or fast recovery diodes since ordinary diodes would not be able to work with high-frequency voltages.

Step 7 - Output Filters

Output Filters

The inductor - This has the function of eliminating the high-frequency harmonics so that they do not travel to the equipment that will be fed, imagine if these harmonics pass to a micro-controller for example, could cause undue loads and errors of reading in the control processes.

And the Capacitors - They are the ones that filter and stabilize the voltage at the output, avoiding ripples and instabilities at the output.

Driver Transformer

PWM control

Primary Power Supply VSB

Fig. 1 - 5W BTL Audio Amplifier PCB

A Missing Current Limiter (MCL) is built-in. The MCL circuit is activated when the difference in current between the output terminal of each amplifier exceeds 100 mA (300 mA Typ.). This level of 100 mA allows for headphone applications (single-ended).

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This TDA7056 audio amplifier will provide a maximum output power of 5 watts into an 8 ohms load using a 6 volts power supply, or maximum output power of 3 watts into a 16 ohms load using an 11 volts power supply.

Fig. 2 - Schematic TDA7056 Audio Amplifier

The audio gain of the  IC is internally fixed at 40 dB. The maximum input voltage supported by this circuit is 18 volts. As we can see in the Figure 2  circuit diagram, we will need only a few components to build this audio amplifier.

VOLUME CONTROL

In conventional DC volume circuits, the control or input stage is coupled to the output stage via external capacitors to keep the compensation voltage low. In the TDA7056B, the DC volume control stage is integrated with the input stage, so coupling capacitors are not required. 

With this configuration, a low compensating voltage is still maintained and the minimum supply voltage remains low.

FEATURES

• DC volume control
• Few external components
• Mute mode
• Thermal protection
• Short-circuit proof
• No switch-on and switch-off clicks
• Good overall stability
• Low power consumption
• Low HF radiation
• ESD protected on all pins.

Material list

• U1........................... TDA7056 – Audio Amplifier Integrated circuit
• C1 .......................... 1uF - 25V – Electrolytic capacitor
• C2 .......................... 0.47uF – Polyester Capacitor
• C3 .......................... 100uF - 25V – Electrolytic capacitor
• R1 .......................... 100K ohms - 1/8 W – "brown, black, yellow, gold"
• R2 .......................... 1K ohms - 1/8 W – "brown, black, red, gold"
• RP1 ........................ 22 k ohms –  Potentiometer
• P1, P2, P3 ............... Kre Block Terminal Terminal 2-Way Double Connector
• Miscellaneous ........ Printed Circuit Board, tin, wire, etc.
  
  

We are offering to download the link with the printed circuit board printing files, they are; Gerber, PDF layout, PNG, all the files with a direct link to Mega.

Direct link to download

Main Features

Arduino UNO is a microcontroller board based on the ATmega328P. It has 14 digital input/output pins (of which 6 can be used as PWM outputs), 6 analog inputs, a 16 MHz ceramic resonator, a USB connection, a power jack, an ICSP header and a reset button. 

• PinOut - ARDUINO Mega Rev3 Board - ATMega328PU
• What is Arduino?
• How to Install Arduino Software (IDE) on Windows - Step by Step!

It contains everything needed to support the microcontroller; simply connect it to a computer with a USB cable or power it with a AC-to-DC adapter or battery to get started. 

You can tinker with your UNO without worrying too much about doing somethin

Click here to Datasheet

Source: arduino.cc