Input Impedance Booster Amplifier Op-Amp Circuit

Introduction

The Input Impedance Booster Amplifier Op-Amp plays an important role in determining the overall performance of the circuit. Low input impedance may lead to a loss of signal strength and a reduction in the overall signal-to-noise ratio. Moreover, low input impedance may adversely affect the frequency response of the amplifier circuit, leading to distortion of the signal. To overcome these problems, a simple and efficient input impedance booster amplifier circuit using TLC271 IC can be designed.

The TLC271 is a single operational amplifier that provides high input impedance, low offset voltage, and low noise. It is a general-purpose amplifier that can be used in various applications, including analog signal processing, filtering, and amplification. The circuit described in this article uses a TLC271 op-amp to boost the input impedance of the amplifier circuit and improve its performance.

The resistance that sets the d.c. operating point is the sole determinant of the input impedance for a.c.-coupled op amp circuits. When standard op amps are employed, the input impedance (Zin) is generally less than 10 ΜΩ, whereas, with CMOS op amps, it is typically high (~10 M). To increase Zin, a bootstrap may be utilized, which artificially amplifies the input impedance to an extremely high value. In op amp IC1, resistors R1 and R2 establish the d.c. operating point. Without further intervention, the input impedance would be roughly 20 MS. However, a portion of the input signal is sent back in phase, resulting in a smaller alternating current via R1. Thus, the input impedance formula can be derived as Zin=(R2+R3)/R3. When utilizing the specified component values, Zin approximates 1 GO. The circuit consumes roughly 3 mA of current.

Circuit Diagram

of Input Impedance Booster Amplifier Op-Amp

The input impedance booster amplifier using TLC271 IC can be designed using a few basic components. The circuit diagram of the input impedance booster amplifier circuit is shown below.

**Input Impedance Booster Amplifier Circuit Diagram**

More Circuit Layouts

**LA4440 Amplifier, Tone Control & MP3**

Bass Tone Control Circuit Diagram — **LA4440 Amplifier, Tone Control & MP3**

**Variable Power Supply 0-30V_10A Circuit Diagram**

Stereo Amplifier TDA7297 Dual-Bridge Circuit Diagram — **Variable Power Supply 0-30V_10A Circuit Diagram**

Advantages of the Input Impedance Booster Amplifier Op-Amp

The booster amplifier circuit using TLC271 IC provides several advantages over conventional amplifier circuits. Some of these advantages are discussed below:

High-Input Impedance: The circuit provides a high input impedance of the amplifier circuit, which helps to reduce the loading effect on the signal source. This makes the circuit suitable for use with high impedance signal sources such as piezoelectric sensors.
Low-Noise: The feedback network consisting of R2 and C1 reduces the noise present in the amplifier circuit, which helps to improve the signal-to-noise ratio.
Low-Power Consumption: The TLC271 IC used in the circuit has a low-power consumption of approximately 150 µA, which makes the circuit suitable for battery-powered applications.
Simple Circuit Design: The circuit has a simple design that is easy to assemble and requires only a few components.

Conclusion

The input impedance booster amplifier using TLC271 IC is a simple and efficient amplifier circuit that provides high input impedance, low noise, and low power consumption. The circuit can be used in various applications where a high-input impedance is required, such as in low-level signal amplification and sensor interfacing. Moreover, the circuit can be modified by changing the values of resistors R1 and R3 to suit different applications. Overall, the amplifier is a useful circuit design for electronic enthusiasts and hobbyists.