Tda2050 vs lm1875

In this article, we are going to compare two hi-fi audio amplifier ICs, TDA2050 vs LM1875 explains the comparison between two amplifiers’ IC features and special functions.


tda2050 lm1875
output power 50 Watt 30 Watt
Current Capability 5A 4A
Supply Range -25V to +25V 16V-60V
Distortion Very low distortion Low Distortion: 0.015%, 1 kHz, 20 W
Protection Short-circuit protection (OUT to GND) Protection for AC and DC Short Circuits to Ground
Package Available in 5-pin TO220 package Plastic Power Package TO-220
Applications • Used for Audio signal Amplification

• Suitable for high power amplification

• Capable of operating on dual/split power supply

• Can be used to cascade audio speakers

• High-Performance Audio Systems

• Bridge Amplifiers

• Stereo Phonographs

• Servo Amplifiers • Instrument Systems


In electronics, amplifiers are considered as one of the most complicated circuit designs, due to their sensitivity and complex nature of circuits.

For this discussion, we are expecting a good comparison between TDA2050 vs LM1875 amplifier ICs in every aspect of audio system operations and functions.


Tda2050 vs lm1875
Tda2050 vs lm1875

Basic comparison 

The TDA2050 and LM1875 are the very common amplifier ICs, each of the amplifier ICs are high power delivering amplifier systems, but we consider in-depth features of the ICs, both the tda2050 and LM1875 have their advantages and disadvantages.

When we consider the power rating, TDA2050 have high power delivering than LM1875, both of them are class AB amplifier type.


 pinout diagram 


pinout diagram of lm1875
pinout diagram of lm1875


The pinout details of the TDA2050 vs LM1875 ICs are the same, each of the ICs is identical with a monolithic casing.

Each of the amplifier ICs had 5 terminal pins, first two pins are non-inverting and inverting pins, which are also known as amplifier circuit positive and negative ports.

Then third and fifth pins are power supply terminals of the amplifier, the third pin is ground and the fifth pin is the positive supply port.

The last fourth pin is our amplifier output terminal, this pattern of amplifier IC terminals are the same in both TDA2050 and LM1875.


Voltage rating 


The input voltage rating of both amplifier ICs is different, TDA2050 has the range of 4.5v to 50v voltage range, which means they could deliver a higher wattage rating.


But in the case of LM1875 amplifier ICs, they had a 16v to 60v voltage range, compare to tda2050, LM1875 has a high input voltage range, but they don’t have a high power-rating TDA2050.


current rating 


The current ratings of both amplifier ICs are almost the same, TDA2050 can deliver 5amps of current when we consider LM1875 amplifier IC, and they have an output peak current of 4amps. 


Protection systems 


We know both TDA2050 and LM1875 are identical amplifiers IC, so the protection systems each of them provide is the same, short circuit protection and thermal shut down include at both ICs.

At LM1875 IC, internal output protection diodes and protection for AC and DC short circuit to the ground are the special systems.


power supply 


The power supply circuit of any amplifier circuits have a major role to play, here TDA2050 IC need a higher voltage rated power supply, so at transformer section 15-0-15, 1amp center-tapped will be used, and then we can use any linear regulator power supply comfortable for the amplifier operation, at output +/- 25volt, the voltage range will be fixed in terms of the amplifier circuit.


For the LM1875 amplifier IC, transformer section 15-0-15 center-tapped will be used, and filter and linear regulator, 25v to 30v will be fixed for LM1875 IC.


If it is LM1875 or TDA2050, the power supply voltage will be fixed in terms of the amplifier output and load.


Wattage output and output load 


The power an amplifier can deliver will be explained with a speaker load, TDA2050 can deliver 32w into 8 ohms at +/- 22v supply and 50w into 4ohm load at 25volt supply.


An LM1875 IC can have the ability to deliver 20watt into 4ohm or 8ohm load, 30w into 8ohm load at +/- 30 volt supply.


The different power variations both TDA2050 vs LM1875 deliver from different power supply voltages.


Special features 


Both the TDA2050 and LM1875 ICs are class AB type amplifiers so, very low distortion is common for them.

TDA2050 has high power (up to 50w) and high current (up to 5A) carrying capability over LM1875 ICs, and LM1875 has high voltage capacity over TDA2050 and has internal output protection diodes.

 TDA2050 and LM1875 basic amplifier circuit comparison 


lm1875 amplifier circuit
lm1875 amplifier circuit


When we comparing both the TDA2050 based and LM1875 based basic amplifier circuits, almost all the functions of the dual power supply-based TDA2050 amplifier and LM1875 amplifier are the same.


tda2050 amplifier circuit
tda2050 amplifier circuit


The power supply both the circuit can implement is different due to the output power, each can deliver.

At input section of the TDA2050 amplifier have input capacitor C1 for DC decoupling and gain setting the purpose and a resistor R1 for the impedance setting, this working is also the same at LM1875 based amplifier, but here R1 and R2 are used to gain setting the purpose and you can change the resistance value of R1 for changing gain at the amplifier.


At input LM1875 amplifier have an extra feature over TDA2050 amplifier, it is the humming sound reducer network, C1, C2 and R2, R3 component network which is for filter out noise, while the R5 acts as pull out resistor, this resistor used to reduce hum sound at the amplifier circuit, which works as allowing a path to ground if no signal is connected (hum reduction).


Other than the input section, TDA2050 and LM1875 have identical circuit working, at TDA2050 R3 resistor acts as a negative feedback element, at the same time R1 resistor is used for feedback on LM1875 amplifier.


The efficiency of TDA2050 and LM1875


We know both the ICs are class AB type amplifier, so a range of 75% is the common range, but here TDA2050 have 70% efficiency and LM1875 is 60 % efficient.

These efficiency values are taken from practical data.


Applications of TDA2050 


  • Hi-fi amplifiers
  • High-end TV sets
  • Vehicular amplifier applications

 Applications of LM1875


  • High-performance audio systems
  • Bridge amplifiers
  • Stereo phonographs
  • Servo amplifiers 
  • Instrument systems

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