GXSC AFE Replaces ADS1294R in EMG Rehabilitation Physiotherapy Devices via Hardware and Software Compatibility

Electromyography (EMG) rehabilitation physiotherapy devices are intelligent medical equipment used for sports injury recovery and neurological function training. Surface EMG signals are weak bioelectric signals generated during human muscle contraction, which can intuitively reflect muscle activation levels, muscle strength status, neural control capability, and limb movement intention. They serve as the signal basis for smart rehabilitation devices to deliver precise therapy and active training. A high-precision, highly integrated bioelectric analog front-end (AFE) is required to ensure EMG waveform integrity and the effectiveness of rehabilitation therapy.

GXSC‘s 24-bit Σ-Δ high-precision bio-potential analog front-end chip is specifically designed for weak human bioelectric signal acquisition scenarios. It integrates a programmable gain amplifier (PGA), high-precision analog-to-digital converter, built-in reference source, right-leg drive circuit, and lead-off detection function. Featuring ultra-high input impedance, an exceptional 105dB common-mode rejection ratio (CMRR), microvolt-level weak signal recognition, multi-level programmable gain, ultra-low power consumption, and an extremely simple peripheral architecture, this chip is fully adapted to the acquisition characteristics of weak EMG signals with a wide dynamic range.

The GXSC AFE operates at output data rates from 250SPS to 64kSPS. At 250SPS, it achieves an IRN performance of 1.28μVpp (0.23μVrms); at 64kSPS, it offers a -3dB bandwidth of 14.4kHz. It features pull-up/pull-down resistors, excitation current sink/source, and AC lead-off detection capability. Additionally, the chip supports daisy-chain configuration, solving data cascade issues in high-channel-count systems. With a maximum digital buffer depth of 16, it can minimize data retrieval frequency, thereby reducing system power consumption.

Key Features of the GXSC AFE:

Input-Referred Noise: 1.28μVpp (0.23μVrms); (BW = 70Hz, G = 24)

Data Rate: 250SPS to 64kSPS

Common-Mode Rejection Ratio (CMRR): -118dB

Programmable Gain: 1, 2, 3, 4, 6, 8, 12, 24

Single Supply Voltage: Analog supply: 2.75V to 5.25V; Digital supply: 1.8V to 3.6V

Built-in or External Reference, Built-in or External Clock (internal clock can be output)

Built-in Bias Amplifier, Lead-Off Detection, Temperature Sensor

Test Signal and Power Supply Measurement Functions

Supports up to 16-Deep Digital Buffer

Flexible Power-Down and Standby Modes

SPI Interface with Daisy-Chain Support

Excellent ESD Capability: HBM: ±8000V; CDM: ±1500V; Latch-Up: 600mA

Operating Temperature Range: -40°C to +85°C