With continuous advancements in medical technology and deepening research in life sciences, the precise measurement of bioelectrical signals has become increasingly crucial in modern medical equipment. From electroencephalography (EEG) to electrocardiography (ECG), fetal heart monitoring, and sleep studies, the acquisition of bioelectrical signals has become an indispensable component of both medical devices and wearable technology. Meanwhile, as demands for device size and power efficiency increase, traditional precision acquisition systems have gradually revealed issues such as large size, high power consumption, and complex equipment.

The CBM24AD92-2CQ by Corebai Microelectronics is a 2-channel, 24-bit synchronous sampling ΔΣ analog-to-digital converter (AFE) specifically designed for human bioelectrical signal acquisition. It is primarily targeted at medical monitoring scenarios such as electroencephalography (EEG) and electrocardiography (ECG), meeting the miniaturization and high-precision R&D requirements of wearable brain-computer interfaces and portable medical devices. With its low-noise, high-precision signal acquisition capability, highly integrated hardware design, medical-specific functional configurations, and industrial-grade stability and reliability, the product precisely addresses the R&D pain points in the field of bioelectrical signal acquisition. It effectively resolves core challenges in this domain, including weak signal capture, device miniaturization, and scenario adaptability. This makes it an ideal choice for electronic engineers and product selection managers in the development of bioelectrical acquisition devices.

The chip ensures precise acquisition of microvolt-level bioelectrical signals with high-performance electrical parameters, featuring input reference noise as low as 1.2μVpp within the 0.01Hz to 70Hz bandwidth, and input bias current controlled within ±300pA across the full temperature range, effectively reducing signal distortion. The 24-bit high resolution combined with an adjustable sampling rate of 250 to 16,000 SPS accommodates both conventional low-speed monitoring and high-speed laboratory research requirements. With a-120dB common-mode rejection ratio, it efficiently suppresses 50/60Hz power line interference, while the 0.2% frequency response (FS) channel gain matching ensures consistent dual-channel acquisition, providing precise data support for multi-electrode signal analysis.

The high-integration design significantly simplifies the hardware development process. The chip incorporates a 4.6V high-precision internal reference and a 2.048MHz clock oscillator, eliminating the need for additional external components. It features programmable gain in multiple steps (1x,2x,4x,6x,8x,12x, and 24x), enabling flexible matching of different amplitude signal acquisition requirements for EEG and ECG. The standard SPI interface (CPOL=0, CPHA=1) ensures full compatibility with mainstream MCUs and processors. The DAISYIN Juhua Chain input pins support multi-device serial networking, overcoming the 2-channel limitation to achieve multi-lead acquisition expansion. Additionally, the ultra-compact package adapts to high-density PCB layouts, facilitating portable device design.

For medical bioelectrical acquisition scenarios, the chip incorporates dedicated functional modules to achieve precise scenario-specific adaptation. The human body bias/right leg drive amplifier utilizes low-noise and low-power characteristics to achieve common-mode noise suppression. The electrode drop detection module supports four configurable constant current sources, enabling real-time verification of electrode contact status. Channel 1 can be independently configured for respiratory detection mode, while the PACE pin facilitates independent pacemaker signal output. A single chip can accomplish multi-parameter synchronous monitoring, with built-in standard test signals also available for self-calibration and system debugging, eliminating additional development and testing costs.

The chip delivers industrial-grade reliability and low-power design, operating reliably across-40℃ to +85℃. It features ESD protection with HBM±2kV and CDM±500V, while its superior thermal performance ensures stable operation in harsh environments. With multiple power modes, it achieves a low power consumption of 14μW in power-off mode and rapid wake-up in standby mode. Supporting single/double-pole power supply solutions (4.75～5.25V analog and 1.8～3.6V digital), it is compatible with mainstream power sources like lithium batteries and USB, meeting the battery-powered wearable device endurance requirements.

application scenarios

electroencephalogram （EEG）

The CBM24AD92-2CQ, with its low-noise performance and high common-mode rejection ratio, accurately captures weak electroencephalogram (EEG) signals, enabling clinicians to achieve precise brain function diagnosis.

electrocardiogram （ECG）

As a critical tool for monitoring cardiac health, the CBM24AD92 can accurately acquire electrophysiological data from the heart. Equipped with an integrated low-noise gain amplifier, this device effectively captures subtle current variations, thereby assisting physicians in detecting potential cardiac abnormalities.

Fetal electrocardiogram monitoring

In fetal health monitoring, accuracy is paramount. The CBM24AD92-2CQ can be used for fetal electrocardiogram (ECG) measurements, enabling real-time monitoring by physicians and ensuring the reliability and precision of data. Its low-power consumption characteristics also make this application an ideal choice for portable monitoring devices.

Sleep Monitoring and Bioelectrical Signal Monitoring

For real-time acquisition of sleep research and other bioelectrical signals, the CBM24AD92-2CQ provides high-resolution signal acquisition capabilities, meeting the demands for high-precision physiological signals. Its built-in multiplexer, test signal source, and electrode monitoring functions enable it to excel in these high-demand application scenarios.