The Coriolis flowmeter serves as the cornerstone for high-precision mass flow measurement in industrial applications, where its performance directly determines the accuracy and stability of process control. Current industry solutions often face challenges including sensor signal interference, reliance on imported analog components, and inadequate long-term reliability under extreme conditions. Leveraging its proprietary domestic analog signal chain core chip, Corebai Micro has developed localized Coriolis flowmeter solutions. These solutions achieve full self-sufficiency in core components—from signal conditioning to auxiliary acquisition—effectively meeting industrial-grade requirements for high precision, reliability, and interference resistance.

1. Overall Plan Structure

This solution adopts a core architecture of "front-end signal conditioning-core data acquisition-algorithm processing-closed-loop drive-multi-mode industrial output-power management" to establish a complete industrial-grade signal processing closed loop. All key analog components across the entire chain utilize domestic products from Corebai Micro, effectively mitigating supply chain risks.

1. Front-end signal conditioning: The three-phase vibration signals (Phase 1/2/3) and one temperature signal (Temp) output by the Coriolis sensor are amplified, filtered, and impedance-matched by Corebai Micro's high-precision operational amplifier, enhancing the signal-to-noise ratio of weak signals to provide high-quality input for subsequent acquisition.

2. Core data acquisition: The conditioned analog signal is fed into a 4-channel Sigma-Delta ADC (4CH SD.ADC) to perform high-precision analog-to-digital conversion of phase and temperature signals, delivering reliable digital signals for flow rate calculation.

3. Algorithm processing: After receiving digital signals, the floating-point DSP executes core algorithms including phase difference calculation, flow rate calculation, and temperature compensation. The filtered signals then yield precise measurement results.

4. Closed-loop control mechanism: The DSP outputs control signals to the Power Driver, generating a 1kHz stable drive signal to maintain normal vibration of the flowmeter's vibrating tube. Simultaneously, the vibration signal is fed back to the ADC, forming a closed-loop measurement system that ensures measurement continuity and stability.

5. Multi-mode industrial output:

l Local display: Visualize key parameters such as flow rate and temperature.

l 4-20mA Output: A standard industrial analog output compatible with mainstream PLC/DCS control systems.

l Serial Driver: Serial digital output supporting remote data transmission and system integration.

6. Power Management: The Power Manager module converts 24V industrial input into stable power for all system modules, powering ADC, DSP, Power Driver, and output modules while preventing power interference to enhance system reliability.

II. Core Chip Selection

The core solution utilizes the CBM8333 or CBM8511 precision operational amplifier and CBM76AD06Q multi-channel ADC chip, serving as the primary components for front-end signal conditioning and auxiliary signal acquisition, respectively.

(1) CBM8333: The Core Choice for Industrial Front-end Signal Conditioning

The CBM8333 is a precision zero-drift CMOS operational amplifier with ultra-low power consumption, mass-produced by Corebai. Specifically engineered for industrial weak signal conditioning, its core performance is optimized to meet the signal processing requirements of Coriolis flowmeter sensors.

1. High precision and low drift ensure long-term measurement stability: at 25℃, the maximum input offset voltage is 30μV, with a typical drift of 0.05μV/℃, effectively preventing temperature-induced measurement errors and meeting the accuracy requirements for continuous long-term operation of flow meters.

2. High anti-interference performance for industrial environments: features a typical Common Mode Rejection Ratio (CMRR) of 110dB and Power Supply Rejection Ratio (PSRR) of 115dB. The built-in RF anti-electromagnetic interference filter effectively suppresses common-mode noise and RF interference from industrial equipment like frequency converters and motors, while accurately capturing sensor signals at the mV/μV level.

3. Low-power wide supply for industrial equipment deployment: Supports +1.8V to +5.5V single power supply, with each amplifier featuring a typical static current of just 25μA, delivering both low power consumption and flexible power options compatible with industrial equipment's lithium batteries, DC power supplies, and other power sources.

4. Industrial-grade wide-temperature operation and flexible packaging: Operating temperature ranges from-40℃ to +125℃, suitable for extreme environments like outdoor and chemical plants. Available in compact packages including SOT23-5, SC70-5, and SOP-8, significantly reducing PCB layout space and meeting the miniaturization requirements of flow meter devices.

5. Track-to-track input/output to enhance signal dynamic range: Both input and output support rail-to-rail operation, maximizing the power supply voltage range to prevent clipping of weak signals and further improving signal conditioning integrity.

(2) CBM76AD06Q: Optimal Adaptation for Multi-channel High-precision Auxiliary Acquisition

The CBM76AD06Q is a 16-bit, 8-channel synchronous sampling analog-to-digital converter (ADC) mass-produced by Corebaiwei. It delivers high-precision and highly reliable auxiliary signal acquisition for the system, serving as the core component for flowmeter system condition monitoring and error compensation.

1. With high precision and linearity, it ensures accurate and reliable data acquisition: featuring 16-bit resolution, with both integral nonlinearity (INL) and differential nonlinearity (DNL) within ±0.5LSB. The signal-to-noise ratio (SNR) reaches 95.5dB under 16x oversampling and ±10V range, while total harmonic distortion (THD) is as low as-107dB. It can accurately capture auxiliary signals such as power supply voltage and ambient temperature.

2. 8-channel synchronous sampling enables simultaneous multi-parameter monitoring: The system supports synchronized sampling of 8 analog signals, which can be divided into two independent channels for parallel acquisition. This allows simultaneous collection of multiple system status signals, providing abundant data for algorithmic compensation.

3. Industrial-grade protection with wide input range for complex applications: The analog input pins feature 7kV ESD-rated protection, with input clamping capable of handling ±16.5V voltage. Supporting ±5V and ±10V true bipolar analog input ranges, it is perfectly suited for industrial high-voltage and multi-interference environments.

4. Highly integrated design simplifies peripheral circuitry: featuring a built-in second-order anti-aliasing filter, 1MΩ high-impedance input buffer, and on-chip 2.5V precision reference voltage with buffer, eliminating the need for external components. This significantly simplifies circuit design and reduces hardware integration complexity and costs.

5. Low-power multi-interface design with practicality and flexibility: Operates at 100mW in normal mode and 25mW in standby mode, meeting energy-saving requirements. Supports parallel, QSPI, and MICROWIRE interfaces for seamless integration with mainstream DSPs, enhancing solution adaptability. Operating temperature ranges from-40℃ to +85℃, perfectly suited for industrial environments.

(3) CBM8511: Future high-end scenario upgrade reserve (not mass-produced)

The CBM8511, a high-precision operational amplifier developed by Corebai Micro, is not yet in mass production. This solution reserves a hardware upgrade path for the chip, enabling direct deployment in high-end applications with extreme interference, such as petrochemical and high-voltage power systems, once mass production begins. The chip features a typical CMRR/PSRR of 130dB, demonstrating exceptional anti-interference capability. It supports shutdown functionality for dynamic power regulation and maintains full compatibility with the CBM8333's package pins, allowing direct replacement during mass production without PCB layout modifications. This ensures seamless technical support for future solution upgrades.

III. Core Values of the Plan

This solution leverages Corebai Micro's domestically developed analog signal chain chips to achieve self-reliance in flowmeter core components, mitigating import supply chain risks. The chips' high precision, low drift, and strong anti-interference capabilities, combined with a fully closed-loop architecture, address critical challenges in industrial measurement such as weak signal extraction, interference suppression, and long-term accuracy maintenance, meeting stringent industrial-grade performance and reliability standards. The cost advantage of domestic chips and their highly integrated design reduce equipment R&D, production, and integration costs. The solution balances rapid mass production deployment with seamless high-end upgrades, catering to diverse industry and tier requirements. It provides core support for the product series layout of flowmeters and the domestic upgrade of industrial high-precision flow measurement.