Archive for the ‘Amplifier Circuits’ Category

Cascode amplifier

Cascode amplifier is a two stage circuit consisting of a transconductance amplifier followed by a buffer amplifier. The word “cascode” was originated from the phrase “cascade to cathode”. This circuit have a lot of advantages over the single stage amplifier like, better  input output isolation, better gain, improved bandwidth, higher input impedance, higher output impedance, better stability, higher slew rate etc. The reason behind the increase in bandwidth is the reduction of Miller effect.  Cascode amplifier is generally constructed using FET ( field effect transistor) or BJT ( bipolar junction transistor). One stage will be usually wired in common source/common emitter mode and the…

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Log amplifier

Log amplifier. Log amplifier is a linear circuit in which the output voltage will be a constant times the natural logarithm of the input. The basic output equation of a log amplifier is v Vout = K ln (Vin/Vref); where Vref is the constant of normalisation, and K is the scale factor. Log amplifier finds a lot of application in electronic fields like multiplication or division (they can be performed by the addition and subtraction of the logs of the operand), signal processing, computerised process control, compression, decompression, RMS value detection etc. Basically there are two log amp configurations: Opamp-diode…

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Stereo headphone amplifier

LM4910 stereo headphone amplifier. LM4910 belonging to the Boomer series of National Semiconductors is an integrated stereo amplifier primarily intended for stereo headphone applications. The IC can be operated from 3.3V ans its can deliver 0.35mW output power into a 32 ohm load. The LM4910 has very low distortion ( less than 1%)   and the shutdown current is less than 1uA. This low shut down current makes it suitable for battery operated applications. The IC is so designed that there is no need of the output coupling capacitors, half supply by-pass capacitors and bootstrap capacitors. Other features of the IC are…

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Transistor amplifier

Amplifier is a circuit that is used for amplifying a signal. The input signal to an amplifier will be a current or voltage and the output will be an amplified version of the input signal. An amplifier circuit which is purely based on a transistor or transistors is called a transistor amplifier. Transistors amplifiers are commonly used in applications like RF (radio frequency), audio, OFC (optic fibre communication) etc. Anyway the most common application we see in our day to day life is the usage of transistor as an audio amplifier. As you know there are three transistor configurations that…

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Op-amp Circuits

CircuitsToday.com is listing some of the best op-amp circuits present in our sites. There are more than 20 circuits which show the different applications of the op-amp. We are listing the links of our best 15 circuits with detailed descriptions and circuit diagrams. Do not forget to go through the comments section for each post, from where you will get ideas about how to modify the circuit. Also if you have any doubts, feel free to ask them through comments. Before going into detail about the different op-amp application circuits, it is important to know about the basics of op-amp,…

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2×5 W Stereo power amplifier circuit based on BA5417.

BA5417 stereo power amplifier. BA5417 is a stereo amplifier IC with a lot of good features like thermal shut down, standby function, soft clipping, wide operating voltage range etc. The IC can deliver 5W per channel into 4 ohm loud speakers at 12V DC supply voltage. The BA5417 has excellent sound quality and low THD (total harmonic distortion) around 0.1% at F=1kHz; Pout=0.5W. Description. Setup and working of this stereo power amplifier circuit is somewhat similar to the BA5406 based stereo amplifier circuit published previously. C10 and C11 are DC decoupling capacitors which block any DC level present in the…

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BA5406 stereo amplifier circuit

BA5406 stereo amplifier. BA5406 is a monolithic integrated stereo amplifier from ROHM semiconductors. It can deliver 5W per channel into a 4 ohm loudspeaker at 9V supply. Amplifiers based on BA5406 does not require an output coupling transformer and can be operated from a single supply. The operating voltage range is from 5 to 15V DC. This makes the IC suitable for low power car audio applications. Other applications of BA5406 are portable audio players, stereo component systems, television etc. The BA5406 has great channel separation, good channel isolation, small pop-up noise, low noise, low thermal resistance and is available…

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60 watt amplifier circuit

60 watt amplifier STK4038. STK4038 is an integrated AF power amplifier that can deliver 60 watts of output power into a 4 ohm load. The internal fixed current circuitry reduces switch ON/OFF clicks. The IC supports the addition of external circuits for thermal shutdown, pop noise reduction, output short circuit protection etc. Description. The 60 watt amplifier shown below is designed based on the datasheet and performs very well. Capacitor C1 is the input DC decoupling capacitor which blocks any DC level present in the audio input and C12 is the input by-pass capacitor. R1 is the input resistor.C10 and…

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50 watt audio amplifier LM3876

50 watt audio amplifier. LM3876 is a high performance audio power amplifier IC from National Semiconductors. The LM3876 can deliver 50watts of output power into an 8 ohm loudspeaker. LM3876 has excellent signal to noise ratio and has wide supply voltage range. Other features of LM3876 are output to ground short circuit protection, input mute function, and output over voltage protection, etc. Applications of LM3876 are component stereo, compact stereo, surround systems, self powered speakers, etc. Description. The 50 watt audio amplifier  circuit shown below is designed based on the application diagram from the data sheet of LM3876. Some modifications…

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TDA7294 100W Audio Amplifier

100W Audio Amplifier TDA7294. TDA7294 is an integrated, monolithic, Class AB audio amplifier designed specifically for Hi-Fi applications. The IC has a DMOS output stage and can deliver 100W RMS into an 8Ohm speaker at +/-38V dual supply. The TDA7294 has low noise, low distortion, good ripple rejection and can be operated from a wide range of supply voltages. The IC has built in short circuit protection and thermal shutdown circuitries. The IC is available in multiwatt 15V and multiwatt 15H packages. Description. In the circuit TDA7294 is configured to provide 100W output power into an 8Ohm loudspeaker at +/-…

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