In the field of Analog-to-Digital Conversion (ADC), Analog Devices Inc. (ADI)'s AD7606 series can be called an "evergreen product". With its strong market adaptability and robust performance, it contributes billions of RMB in profits to the company every year and has become a benchmark product in the mid-to-high-end industrial data acquisition market. Its success is not accidental but an inevitable result of accurately addressing industry pain points.
The core advantage of the AD7606 series lies in achieving a perfect balance between "high performance" and "high integration". As a 16-bit multi-channel synchronous sampling ADC, it boasts a high signal-to-noise ratio (SNR) of 95.5 dB and a low total harmonic distortion (THD) of -107 dB. The nonlinear error within ±0.5 LSB ensures the accuracy of signal conversion, enabling it to capture extremely subtle changes in analog signals. Meanwhile, the chip integrates a second-order anti-aliasing filter, a 2.5V reference voltage source, and ±16.5V voltage clamping protection. The high input impedance of 1 MΩ eliminates the need for an external driver op-amp, and the 5V single power supply is compatible with various industrial architectures, greatly simplifying circuit design and enhancing anti-interference capability.
The series covers multiple segmented models to accurately meet the needs of different scenarios. The basic model AD7606 features an 8-channel configuration, while the AD7606-6 and AD7606-4 are 6-channel and 4-channel respectively, all supporting 200 KSPS full-channel synchronous sampling, suitable for monitoring requirements with different channel counts. Among the upgraded models, the AD7606B increases the sampling rate to 800 KSPS, and the AD7606C-16 and AD7606C-18 achieve a sampling rate of 1 MSPS, with the latter having a resolution of up to 18 bits, meeting the needs of high-end instrumentation.
The wide coverage of application scenarios is the key to its high profits. In the power industry, the 8-channel model perfectly matches the monitoring requirements of "three-phase voltage + three-phase current + bus voltage + zero-sequence current", with a penetration rate of nearly 100% in smart substations. In the field of industrial control, its synchronous sampling capability is suitable for multi-axis industrial control systems and PLC equipment; in rail transit and aerospace fields, its wide temperature range stability is highly valued. The annual procurement volume in the Chinese market exceeds 10 million units, and the unit price remains stable at several dozen yuan, with economies of scale continuously driving up profits.
The success of the AD7606 series essentially stems from a profound insight into the core needs of industrial scenarios, building a competitive barrier with the combined advantages of "precision + stability + integration", making it a well-deserved "profit engine" for ADI. In fact, as a key link connecting digital systems and the analog world, Digital-to-Analog Conversion (DAC) chips have far more application scenarios than just the industrial field, playing a core role in many high-end and civilian fields:
In the consumer electronics field, high-fidelity audio equipment is a typical application scenario for DAC chips. For example, 24-bit high-precision DAC chips such as Rion MS5282N, with a high dynamic range of 110 dB and a low THD of 0.003%, have become core components of high-end Hi-Fi audio systems, home theaters, and in-vehicle audio systems. They can accurately restore subtle details in digital audio signals, presenting cinema-level surround sound effects. Entry-level DAC chips are also integrated in smartphones and digital set-top boxes, converting stored digital music files into analog audio signals to drive headphones or speakers, directly determining the sound quality performance of the devices.
The medical electronics field has extremely high requirements for the precision and stability of DAC chips. In Magnetic Resonance Imaging (MRI) equipment, ADI's 20-bit high-precision DAC chip AD5791, with a resolution of parts per million (ppm) level and extremely low output noise, can accurately generate analog waveforms that control radio frequency signals, reducing imaging artifacts, improving the clarity of diagnostic images, helping doctors judge lesions more accurately, and shortening the patient's scanning time. In addition, DAC chips are also equipped in ultrasonic diagnostic instruments and electrocardiogram monitors, used to generate analog waveforms required for detection or convert digitized patient physiological signals back to analog form for doctors to observe.
In the fields of communications and industrial control, DAC chips are the core of signal generation and equipment regulation. In wireless communication base stations, high-speed DAC chips convert baseband digital signals into analog radio frequency signals, which are amplified and transmitted through antennas. Their performance directly affects the stability and anti-interference capability of signal transmission. In industrial automation scenarios, DAC chips provide precise analog control signals for PLCs, frequency converters and other equipment, enabling refined adjustment of parameters such as motor speed and valve opening. For example, the MS5282N significantly improves the measurement accuracy and reliability of industrial control systems with its 24-bit resolution and low noise characteristics.
In the field of instrumentation, DAC chips are core components of waveform generators, digital oscilloscopes and other equipment. By outputting precisely controllable analog voltage or current waveforms, they can perform performance testing and calibration of electronic equipment. For example, in laboratories, DAC chips can generate standard waveforms such as sawtooth waves and sine waves, and cooperate with ADC chips to complete signal collection and analysis of the tested equipment, forming a complete measurement and control closed-loop system.
Against the backdrop of accelerating localized substitution in the semiconductor industry, several domestic ADC chips have emerged as potential alternatives to the AD7606 series, though they still face certain technical and market challenges.
Key domestic alternative solutions mainly come from leading local manufacturers and research institutions with strong analog circuit capabilities. First, products from the 24th Research Institute of China Electronics Technology Group Corporation (CETC 24), a professional analog integrated circuit research institute, stand out. Its 16-bit multi-channel synchronous sampling ADCs, covering 8-channel, 6-channel, and 4-channel configurations, have performance indicators close to the AD7606 series, with a sampling rate of up to 200 KSPS, which can meet the basic needs of industrial data acquisition. Second, Suzhou Yunxin Microelectronics, founded by returnee doctors with experience at ADI, offers 16-bit ADC products with a sampling rate range of 65-125 MSPS. These products have reached export-controlled specifications and are suitable for industrial control and communication fields that require medium-to-high speed sampling. Additionally, Chengdu Huaxin Microelectronics has launched high-speed and high-precision ADCs such as the HWD12B16GA4, which, although focusing more on the RF direct sampling field, its multi-channel synchronous sampling technology and integration capabilities provide technical support for substituting the AD7606 in specific high-end scenarios.
Despite the progress in domestic alternatives, they still face three major core issues. Firstly, there is a gap in key performance indicators. Compared with the AD7606's 95.5 dB signal-to-noise ratio and -107 dB total harmonic distortion, most domestic products have slightly inferior dynamic performance, leading to insufficient accuracy in capturing subtle analog signals, which restricts their application in high-precision fields such as high-end instrumentation. Secondly, the maturity and consistency of mass production are insufficient. International giants like ADI have decades of production experience, ensuring stable chip performance across batches. In contrast, domestic manufacturers, especially startups, often struggle with inconsistent parameters between batches due to shorter mass production cycles and immature process control, increasing the risk of system failures for end users. Thirdly, the supporting ecosystem is incomplete. The AD7606 has a complete technical documentation system, rich application cases (such as the AD7606 capture case based on domestic FPGA development boards ), and mature driver libraries. However, domestic alternatives often lack detailed application notes and technical support, requiring downstream enterprises to invest additional resources in adaptation and debugging. Moreover, the lack of long-term reliability verification data in extreme environments such as wide temperature ranges also makes downstream customers hesitant in large-scale adoption.
In conclusion, domestic ADC chips have initially possessed the capability to substitute the AD7606 in medium and low-end industrial scenarios, but there is still a long way to go in terms of performance improvement, mass production stability, and ecosystem construction. With continuous national policy support and increased R&D investment by enterprises, it is expected that domestic alternatives will gradually make breakthroughs in core technologies and narrow the gap with international leading products.
