ADI LT1028 Op Amps Low Noise Operational Amplifier

LT1028 Op Amps Low Noise Operational Amplifier General Description

The LT1028 and LT1128 are high-performance operational amplifiers (op-amps) designed to provide extremely low noise and high precision for a wide range of applications. 

These op-amps are known for their exceptionally low noise characteristics. They have a voltage noise of 0.85nV/√Hz at 1kHz and 1.0nV/√Hz at 10Hz. This low noise level makes them suitable for applications where noise is a critical factor, such as high-precision measurements and instrumentation.

Despite their low noise, the LT1028 and LT1128 also offer high-speed performance. The LT1028 has a gain-bandwidth product of 75MHz, while the LT1128 has a gain-bandwidth product of 20MHz. This makes them suitable for applications that require both low noise and high-speed signal processing.

The LT1028 is stable at a gain of -1, while the LT1128 is stable at a gain of +1. This allows you to configure the op-amp for inverting or non-inverting amplifier configurations, depending on your specific application requirements.

These op-amps provide true precision parameters, with low drift (0.1µV/°C), low offset voltage (10µV), and a high voltage gain (30 million). This level of precision is essential in applications where accuracy and stability are critical.

Despite the high collector current in the input stage (approximately 1mA), the input bias current is only 25nA. This low input bias current is important in applications where the input impedance of the circuit needs to be preserved and not significantly loaded.

The voltage noise of the LT1028/LT1128 is less than that of a 50 Ohm resistor. This means that in applications with very low source impedance, such as transducer or audio amplifier applications, the contribution of these op-amps to the total system noise will be negligible.

Pin Configuration

Features

LT1028 Evaluation Kit

The LT1028 Evaluation Kit DC417B is a tool designed to help users evaluate and test the LT1028 operational amplifier. This kit typically includes a variety of components and features to make it easier to assess the performance of the LT1028 op-amp. 

Application

The LT1028 and LT1128 operational amplifiers are well-suited for a variety of applications that require low noise, high precision, and high-speed performance. 

Low Noise Frequency Synthesizers: These op-amps are ideal for low noise voltage-controlled oscillators and frequency synthesizers, where precise signal generation and minimal phase noise are crucial.

High-Quality Audio: In audio equipment, the LT1028 and LT1128 can be used in preamplifiers and audio signal processing circuits to achieve high fidelity and low distortion audio reproduction.

Infrared Detectors: These op-amps can be used in signal conditioning and amplification of low-level signals from infrared detectors, ensuring minimal noise and high sensitivity in infrared applications.

Accelerometer and Gyro Amplifiers: For inertial measurement units (IMUs) and sensor systems, these op-amps are suitable for amplifying signals from accelerometers and gyroscopes with precision and low noise.

350 Ohms Bridge Signal Conditioning: The op-amps can be used for conditioning signals from strain gauges and other bridge transducers, providing accurate and low-noise measurements in strain gauge-based sensor applications.

Magnetic Search Coil Amplifiers: In magnetic field measurement systems, such as magnetic search coil sensors used in geophysics or electromagnetic research, these op-amps can amplify weak magnetic field signals with high precision.

Hydrophone Amplifiers: For underwater acoustics and sonar applications, hydrophones can benefit from the low noise and high precision amplification provided by these op-amps.

Related Parts

Absolute Maxium Rating

Typical Application

What is the difference between LT1028 and LT1128

The primary difference between the LT1028 and LT1128 operational amplifiers lies in their gain configurations and gain-bandwidth products. 

Gain Configuration:

LT1028: The LT1028 is designed to be stable at a gain of -1. This means it is typically used as an inverting amplifier or for applications where signal inversion is required.
LT1128: The LT1128 is designed to be stable at a gain of +1. It is commonly used as a non-inverting amplifier or for applications where signal gain without inversion is needed.

Gain-Bandwidth Product:
LT1028: The LT1028 has a higher gain-bandwidth product of 75 MHz. This means it can provide a wider bandwidth for a given gain setting, making it suitable for applications that require both high gain and high-frequency performance.
LT1128: The LT1128 has a lower gain-bandwidth product of 20 MHz. While it still offers high precision and low noise, it has a more limited bandwidth compared to the LT1028.

LT1028 Replacement

The LT1028 is a precision operational amplifier (op-amp) manufactured by Linear Technology (now part of Analog Devices). If you are looking for a replacement for the LT1028, you can consider other precision op-amps with similar characteristics and performance specifications. 

LT1128: This is another precision op-amp from Linear Technology (now part of Analog Devices). It has similar characteristics and can be a direct replacement for the LT1028.

AD797: This is a precision op-amp from Analog Devices with excellent low noise and low distortion performance. It can be a good replacement for the LT1028 in many applications.

OPA134: The OPA134 is a precision op-amp from Texas Instruments known for its low noise and high accuracy. It's suitable for many precision applications and can be used as an alternative to the LT1028.

OP27: The OP27 is a precision op-amp from Analog Devices with good performance characteristics and is often used as a substitute for the LT1028 in certain applications.

ADA4627: Another precision op-amp from Analog Devices, the ADA4627 offers low noise and high precision performance and can be considered as a replacement for the LT1028.

When selecting a replacement op-amp, make sure to check the datasheets of both the LT1028 and the replacement op-amp to ensure that the electrical characteristics, pinout, and voltage supply requirements are compatible with your specific application. 

LT1028 Spice Model

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