OP07 Operational Amplifier Features, Pin Configuration and Application Scenarios

Ⅰ. Overview of OP07 operational amplifier

Ⅱ. Features of OP07 operational amplifier

Ⅲ. OP07 symbol, footprint and pin configuration

Ⅳ. Working principle of OP07 operational amplifier

Ⅴ. Differential amplifier circuit of OP07

Ⅵ. Application scenarios of OP07 operational amplifier

Ⅶ. What is the difference between the OP07 and other operational amplifiers?

Operational amplifiers have a wide range of applications and are mainly used in situations where various mathematical operations need to be performed on signals, such as amplification, summation, integration, etc. The OP07 operational amplifier is a very practical chip. This article will introduce its parameters, features, working principle and uses in detail to help you better understand and apply the chip.

The OP07 chip is a low-noise, non-chopper-stabilized bipolar (dual power supply) operational amplifier integrated circuit. Because the OP07 has a very low input offset voltage, it does not require additional zeroing measures in many application scenarios. In addition, OP07 also has low input bias current and high open-loop gain. These characteristics make OP07 particularly suitable for high-gain measurement equipment and amplifying weak signals of sensors. OP07 can be used in 8-pin DIP package or TO-99 metal package, which is very convenient to install and use.

Replacements and equivalents:

• AD620

• CA3140

• LF351

• MC33171

• TL081

• It has high input impedance and low output impedance, which has less impact on the loading of external signal sources.

• It boasts minimal noise features, effectively mitigating noise generation and ensuring consistent output signals.

• OP07A has low input bias current of ±2nA.

• It has high open loop gain of 300V/mV.

• OP07 can operate in single or dual power supply mode, which makes it more flexible for different circuit configurations.

• Its input offset voltage is very low, with a maximum value of 25pV, so it does not require additional zeroing measures.

The following figure shows the symbol, footprint and pin configuration of the OP07 operational amplifier respectively.

OP07 has eight pins in total, their names and descriptions are as follows.

Pin 1 (Vos Trim): Used to set offset voltage if required

Pin 2 (IN-): The inverting pin of the op-amp

Pin 3 (IN+): The non-inverting pin of the op-amp

Pin 4 (V-): Connected to negative rail or ground

Pin 5 (NC): Not connected

Pin 6 (Output): Output pin of the op-amp

Pin 7 (V+): Connected to the positive rail of supply voltage

Pin 8 (Vos Trim): Used to set offset voltage if required

The amplification circuit principle of OP07 is an operational amplifier circuit based on negative feedback. When the input signal is applied to the non-feedback port, the output signal is amplified and processed, compared and corrected through the negative feedback loop to obtain the required stability, accuracy and linearity.

OP07 amplifier circuits usually have three basic configurations, namely inverting amplifier, non-inverting amplifier and differential amplifier. Among them, the inverting amplifier is the most common one. In this circuit, the input signal is passed into the non-feedback input (IN+) through resistor R1, while digital ground is connected to the feedback input port (FB). This means that the output signal will also be fed back to IN- through Rf, thereby achieving negative feedback control. This improves the accuracy and stability of the amplifier to a certain extent.

A simple differential amplifier circuit built using OP07 op amp is shown in the figure below. The circuit consists of three operational amplifiers, labeled A1, A2, and A3.

The first two op amps (such as A1 and A2) are combined with the A3 amplifier in a non-inverting configuration. In the circuit below, the A3 op amp is called a subtractor circuit. Here the circuit changes the differential signal between two floating points such as a and b within a single ended o/p voltage.

Typically, the A3 amplifier is used within unity gain and all resistors R4 to R7 etc. are equivalent. Once we use the resistors with 0.1% tolerance, the common mode rejection exceeds 60 dB. In order to further improve the common mode rejection ratio, we can consider adding a potentiometer or adjusting the potentiometer.

Both the A1 and A2 op amps have some differential gain. This is a low-level differential amplifier widely used in signal processing. It is also useful for low frequency signals, typically from thermocouple outputs or sensors that have been modified and propagated in balanced mode. This amplifier circuit is powered at ±15V just to achieve zero i/p offset voltage for the A3 output amplifier.

1. Sensor signal processing

In sensor signal processing, we need to amplify the weak signal output by the sensor to a suitable amplitude and maintain the accuracy and stability of the signal. By connecting the sensor output to the input of OP07, we use its high gain to amplify the signal to a suitable range, and then process it through subsequent circuits to finally obtain accurate sensor data.

2.Voltage control

In voltage control, we need to control the amplitude of the output voltage according to the input voltage. By connecting the input voltage to the non-feedback input terminal of OP07, we use its high gain characteristics to amplify the input voltage to a sufficient amplitude, and then feed the amplified signal back to the feedback input terminal of OP07 through the feedback resistor network, thereby achieving control of output voltage. OP07's high precision and low noise give it good performance in voltage control and can achieve precise voltage control.

3. Audio amplifier

The OP07 operational amplifier has the characteristics of low noise and low distortion, and is very suitable for amplifying audio signals. In audio amplifiers, as a core component, it can provide high-quality audio amplification effects and make the sound clearer and more delicate.

4. Temperature measurement

In temperature measurement, the sensor usually converts the temperature into a voltage signal output. In order to amplify this weak voltage signal to a suitable amplitude, we need to use an operational amplifier. The OP07's high gain and low noise make it ideal for temperature measurements. By connecting the sensor output to the input of OP07, we use its amplification function to amplify the signal to a suitable range, and then process it through subsequent circuits to finally obtain an accurate temperature value.

To begin with, the OP07 operational amplifier boasts a substantial open-loop gain, with the potential to reach 300V/mV. This translates to superior amplification and reduced distortion, ensuring the delivery of a crisp and steady output signal.

Secondly, it also has ultra-low offset and offset voltage drift, good stability and other characteristics. These characteristics make it excellent in many applications, especially in areas such as high-gain measurement equipment and amplification of weak signals from sensors.

Besides, the OP07 operational amplifier has a low input bias current of only ±2nA, which helps improve the sensitivity and performance of the circuit. This low input bias current design avoids adverse effects on circuit accuracy and performance compared to other types of op amps.

In addition, the input offset voltage of the OP07 operational amplifier is very low, with a maximum value of 25uV, so it does not require additional zeroing operations. In contrast, other types of op amps may have higher input offset voltages, requiring additional zeroing operations.

Frequently Asked Questions

1. What is OP07 used for?

The low offset and high open-loop gain make the OP07 particularly useful for high gain instrumentation applications. The wide input voltage range of ±13 V minimum combined with a high CMRR of 106 dB (OP07E) and high input impedance provide high accuracy in the noninverting circuit configuration.

2. What is equivalent to OP07?

Equivalent ICs of OP07 operational amplifier are CA3140, UA741, MC33171, TL081, etc. Alternative ICs of OP07 op-amp are LM4871, IC6283, AD620, LF351, JRC45558, etc. The OP07 operational amplifier is long-term strength & an extremely low offset integrated circuit.

3. What is the use of OP07CP?

The OP07CP offers low offset and long-term stability by means of a low-noise, chopperless, bipolar-input-transistor amplifier circuit. Most external components are not required for offset nulling and frequency compensation.

4. What is the difference between OP07 and OP77?

The OP07 has a quiescent current that is higher than desired in today's portable applications. The quiescent current of the OP77 in-amp is less than 350 μA, while the OP07 requires 4 mA for ±15 V operation. In terms of power consumption, the OP77 allows the part to be designed into many portable applications.