The NL6012, Low Power of 15 µA, Zero-Drift, Rail-to-Rail I/O, High EMC Performance, Dual Operational Amplifier

Press Release

June 29, 2023

Nisshinbo Microdevices Inc. has launched the NL6012, a dual operational amplifier, in June 2023.

In recent years, as people's health concerns and awareness of environmental pollution have grown, the number of companies and organizations seeking to become carbon neutral has increased. In environmental initiatives, environmental measurement instruments are used to collect data such as CO₂ and temperature. In these instruments, environmental sensors first convert external environmental information into electrical signals, and the role of operational amplifiers is to accurately amplify these signals to make them suitable for processing.
The NL6012 is the most accurate operational amplifier in our history, achieving an input offset voltage of 10 µV max and an offset voltage drift of 0.05 µV / °C max. Since the effect on the sensing system can be minimized by accurately amplifying and processing electrical signals, design time and cost associated with the accuracy aspect of the instruments is reduced.

Product Name	NL6012
Sample Price (reference price when purchasing 1000 units, tax Included ^*)	JPY 286
Sample Order Start Date	June 29, 2023
Monthly Production	500,000 pcs

*The price is based on the consumption tax rate as of June 2023.

Features

1. Energy-Saving and High DC Performance

A zero-drift operational amplifier features a low input offset voltage with excellent stability over temperature variations. The NL6012 achieves high accuracy by modulating the DC offset component, shifting it to a higher frequency, and cutting it off, called a chopper-stabilized architecture. This cancels the input offset voltage and the temperature drift. In particular, the stability over temperature is an important characteristic in product design and manufacturing processes, as it is difficult to correct with a microcontroller.

Recently, energy saving in electronic components has been progressing. However, the pursuit of low power will conflict with the performance of ICs. This is also true for a chopper circuit in the zero-drift operational amplifier, and the analog performance of a cancellation circuit itself must be improved to achieve high performance. Although the NL6012 has the low consumption current of 15 µA, it also achieves high performance, i.e., the input offset voltage of 10 µV max. by fine-tuning a current within the IC. Figure 1 shows the offset voltage drift of this product compared to that of the same low power, zero-drift operational amplifiers. Both the Product C and the NL6012 have the same specification value of 0.05 µV / °C max. on the data sheet, but as shown in Figure 2, the actual measured value of the NL6012 is about ±0.01 µV / °C, which is very small and shows good characteristics. As a result, the NL6012 eliminates the need for adjustment operations on the customer's production line or automatic calibration of measuring instruments, contributing to improved labor efficiency and reduced manufacturing costs.

Figure 1. Comparison of Specifications in Datasheets

Figure 2. Comparison of Actual Measured Values

2. Excellent Temperature Stability

The NL6012 has excellent temperature stability. In general, the higher the temperature of a semiconductor device, the more leakage current is generated. Leakage current is a very small current, but in the case of low power operational amplifiers, it can degrade IC performance, including the offset characteristics and the consumption current. Therefore, suppressing leakage current at high temperature will stabilize instruments. The NL6012 achieves high performance even at high temperature by taking thorough measures to prevent leakage at high temperature in each element of the operational amplifiers.

Figure 3 compares the input offset voltage temperature characteristic of the NL6012 with that of a typical zero-drift operational amplifier. The NL6012 exhibits extremely high temperature stability without fluctuation of the input offset voltage even at 125 °C. Therefore, the NL6012 can be used safely in harsh environments such as industrial equipment sensors and factories.

Figure 3. Comparison of Measured Input Offset Voltage Temperature Characteristics of Zero-Drift Operational Amplifiers

3. High Stability against Oscillation Considering the Connection with ADCs

Zero-drift operational amplifiers accurately amplify tiny signals from sensors and transmit them to ADCs. As successive approximation register (SAR) type ADCs, which are widely used in industrial equipment, have become more accurate, the design of a filter connected to the input is important to take advantage of their original performance. Because the filter has a large capacitance in some cases, it can cause reduced stability and oscillation when used with normal operational amplifiers. The NL6012 has highly stable characteristics with a 1000 pF load capacitance, providing low attenuation and maximizing ADCs performance in input filter designs.

Prevents Oscillation with Excellent Filter-Compatible Performance

4．Excellent EMC Performance

With the recent shift to IoT in electronic systems, various systems are connected to the Internet. As a result, electronic components are more susceptible to noises from communication signals. To achieve high-precision measurement, it is also important to have noise immunity so that the input offset voltage value is not affected by these noises. The EMI Rejection Ratio (hereinafter, EMIRR) is an index for noise immunity. This shows the amount of input offset voltage change for the applied 100 mV AC signal input.

The NL6012 has the EMIRR of 100 dB or better at 1.8 GHz, which is mainly used in mobile phones. This value can be converted to the offset voltage of 1 μV. The NL6012 has the EMIRR of 80 dB (the offset voltage of 10 μV) or better over 200 MHz. It supports robust designs for IoT and wireless systems.