An audio preamplifier or preamp is one type of electronic amplifier, used to change a weak input signal into a strong output signal used for a loudspeaker & a power amplifier. These amplifiers are normally used for amplifying analog sensor signals like microphones & pickups. So, this is frequently arranged very close to the analog sensor to decrease the noise & interference effects. There are different op-amps are used in audio pre-amplifier circuits like NE5532, LM258, TL072, OPa2134, RC4588, CA1458, LM358, NJM4560, LM4558, etc. Audio pre-amplifiers are used in different audio gears such as audio interfaces, DJ mixers, large-format consoles, USB microphones, and computer sound cards. This article discusses an overview of TL072 Op Amp, specifications, circuit & its applications.
What is TL072 Op-Amp?
The TL072IC is a high-voltage JFET-input dual op-amp with a high slew rate & low noise versions. The Input bias & Offset currents of this IC is also low. The TL07x series operational amplifiers are available with low noise & low harmonic distortion so, these are used where high accuracy is required like in the audio pre-amplification application. Audio pre-amplification is a method to get low-interference, low-distortion audio o/p, low-noise, and also to adjust bass, treble & volume. Similar to another operational amplifier, this IC simply compares the voltage thus; it can be used as a voltage comparator op-amp.
The pin configuration of TL072 Op Amp is shown below. This IC includes 8 pins and each pin’s functionality is discussed below.
- Pin1 (1OUT): This is the first op-amp’s output pin.
- Pin2 (1IN-): This is the first op-amp’s Inverting input.
- Pin3 (1IN+): This is the Non-inverting pin of the first op-amp.
- Pin4 (Vcc-): This is a Ground pin.
- Pin5 (2IN+): This is the Non-inverting i/p pin of the second op-amp.
- Pin6 (2IN-): This is the Inverting i/p pin of the second op-amp.
- Pin7 (2OUT): This is the output pin of the second op-amp
- Pin8 (Vcc+): It is a voltage supply pin.
Features & Specifications:
The features and specifications of TL072 Op Amp include the following.
- Type of amplifier is J-FET.
- It includes 8 pins.
- This op-amp has low power utilization, Offset currents & Input-bias currents.
- It is available with protection from short circuits.
- Its operation is Latch-up free.
- It is a dual op-amp IC.
- It includes 8 pins.
- It has high Input impedance.
- It has frequency compensation internally.
- It has a differential & also a wide common-mode range of voltage.
- Its harmonic distortion is low usually 0.003%.
- It has less noise at this op-amp operation
- Typical Vn = 18 nV/√Hz at f = 1 kHz.
- Its slew rate is high normally like 13 V/μs.
- Its voltage supply ranges from 6V to 36V.
- Its o/p short circuit duration is infinite.
- Its storage temperature normally ranges from -65 to 150 °C.
- Its operating temperature ranges from -40 to 125 °C.
- Its output current is normally 10mA.
- Its mounting style is through the hole.
- It is available in an 8-DIP package.
- The output current for each channel is 40mA.
- Its bandwidth is 3MHz.
- Its voltage gain is 106.02 dB.
- Its moisture sensitivity level is 1.
- Equivalent TL072 ICs are LM358, OPA827, LT1972, NE5532 and ADA4610-2.
How to use/connect TL072 Op-Amp in a Circuit:
To securely use TL072 op-amp in a circuit, the following steps must be considered.
- The voltage should not apply above 36V.
- The load should not drive above 10 mA.
- This IC must be stored at temperature > -65oC < +150oC.
Tone Control Circuit using TL072 Op-Amp
A tone control circuit generally includes a set of filters that adjusts the signal before it is given to headphones, speakers, or audio recording devices through an amplifier. This circuit simply allows a listener to regulate the generated tune through an audio system. This circuit uses a low noise input TL072 IC which provides low noise o/p including few exterior components and for superior operation, it requires +ve &-ve dual bias supply.
The required components to build this tone control circuit mainly include; TL072 IC op-amp, resistors like 1KΩ, 2.2MΩ, 100KΩ &10KΩ, 100KΩ variable resistor, capacitors like 100pF, 1uF,22nF, 2.2uF, 2uF & 220nF, 15V battery, and connecting wires.
Dual Power Supply Circuit
The op-amp in this circuit requires a dual power supply for better amplification. For that, a dual supply circuit is designed with some basic components. This circuit is designed with a step-down transformer, and a 1A bridge rectifier to convert from AC to DC & filtering capacitors. First, this step-down transformer changes the AC voltage from high to low. After that, this step-down voltage is rectified throughout a 1A bridge rectifier. So this rectifier provides +ve & -ve supply. Furthermore, the rectified DC is simply filtered through capacitors. So finally from this circuit, we can obtain a +15V to 0 to -15V dual supply.
The TL072 op-amp is the most significant component in the below circuit. An audio i/p signal is given first to the op-amp through a balanced circuit made with resistors & capacitors. Here R2 & R3 resistors are placed for amplifier feedback. After that, the amplifier output in the circuit is provided to the tone control circuit which controls treble, bass & balance effects within the audio o/p signal. The output signal to the speaker is received from the VR2 variable resistor. Here this variable resistor is used to provide an extension of the signal for the amplification of another channel.
Tone control circuits are used in various radios, sound systems, portable music players, musical instrument amplifiers, public address systems, boomboxes, etc.
The advantages of the TL072 op amp include the following.
- The low bias currents frequently permit circuitry to be simplified.
- This most popular IC has extremely high-impedance inputs, with efficiently zero offset & bias currents.
- These ICs give excellent noise performance at medium impedances, in the 1 to 10 k Ohm range.
- It is a high-speed i/p single JFET op-amp.
- This IC is not expensive.
- It is an extremely precise audio pre-amplification device.
- It has negligible i/p bias current & i/p current noise.
- It has low power consumption, low noise, latch-up-free operation, high slew rates, and temperature coefficient is low.
Where to Use/Applications
The some areas where TL072 op amps have found common applications:
- Audio Amplification: TL072 is often used in audio amplifiers, such as preamplifiers and headphone amplifiers, due to its low noise and high gain bandwidth.
- Instrumentation Amplifiers: TL072 is suitable for building instrumentation amplifiers used in measuring and sensing applications. It provides high input impedance and low output impedance, making it useful for signal conditioning.
- Active Filters: The TL072 op amp can be employed in active filter circuits, including low-pass, high-pass, band-pass, and notch filters. Its high slew rate and wide bandwidth contribute to accurate filtering of signals.
- Oscillators and Function Generators: TL072 is utilized in the design of oscillators and function generators. Its high gain and stability make it suitable for generating various waveforms accurately.
- Voltage Comparators: TL072 can be used as a voltage comparator in applications where fast response and accurate comparison between two voltage levels are required.
- Voltage References: TL072 can serve as a voltage reference source due to its stable output voltage characteristics.
- Analog Signal Processing: The TL072 op amp is utilized in various analog signal processing applications, such as amplification, buffering, and signal conditioning.
- Active Rectifiers: TL072 can be used in active rectifier circuits to convert alternating current (AC) signals to direct current (DC) signals.
- Data Acquisition Systems: TL072 is employed in data acquisition systems to amplify and condition analog signals before they are converted to digital signals.
- Analog-to-Digital Converters (ADCs): TL072 op amps are sometimes used in conjunction with ADCs to provide signal conditioning and amplification prior to the digital conversion process.
TL072 op amps, known for their versatility and reliable performance, find applications in various household appliances. Here are some examples of how TL072 op amps are used in household appliances:
- Audio Systems: TL072 op amps are commonly used in audio systems found in households, such as stereo systems, amplifiers, and audio receivers. They provide low noise amplification and accurate signal processing, ensuring high-quality audio output.
- Television Sets: It can be found in the audio processing circuits of television sets. They help amplify audio signals from broadcast sources or external devices, delivering clear and balanced sound to complement the visual experience.
- Microwave Ovens: It is used in the control circuitry of microwave ovens. They play a role in signal conditioning, amplification, and control functions, ensuring precise and reliable operation of the oven’s components.
- Washing Machines: TL072 op amps are used in washing machines for various purposes. They can be found in motor control circuits, sensor interfaces, and signal conditioning circuits. These op amps assist in precise control of motor speed, temperature sensing, and water level detection.
- Refrigerators: They are utilized in refrigerator control circuits for tasks such as temperature control, fan speed regulation, and defrost cycle control. They ensure accurate sensing and control of temperature variations, contributing to efficient and reliable refrigerator operation.
- Air Conditioners: They play a role in the control and signal processing circuits of air conditioners. They are used for temperature sensing, thermostat control, and motor speed control, ensuring optimal comfort and energy efficiency.
- Power Inverters: They are used in power inverters, which convert DC power from batteries or solar panels into AC power for household appliances. They assist in generating stable and precise sine wave output, contributing to reliable power conversion.
- Electronic Thermostats: They are employed in electronic thermostats used for heating and cooling control in residential settings. They provide precise temperature sensing, feedback control, and hysteresis functions, allowing for accurate and efficient temperature regulation.
- Lighting Control Systems: They can be found in lighting control systems, such as dimmers and LED drivers. They enable accurate and smooth dimming functionality, ensuring desired lighting levels while conserving energy.
- Home Security Systems: They are used in various components of home security systems, including motion sensors, door/window sensors, and alarm control circuits. They contribute to reliable signal amplification, filtering, and processing, enhancing the overall security of the household.
Please refer to this link to know more about How to select an op-amp?
Please refer to this link for TL072 Op-Amp Datasheet.
Thus, this is an overview of TL072 Op Amp – specifications, circuit, working, advantages & applications. Here is a question for you, what is Non-Inverting OPamp ?