Domestic low-power multi-channel 24-bit ADC GX1298R replaces ADS1298R for application in portable defibrillators (AED)

An Automated External Defibrillator (AED) is a portable medical device capable of diagnosing specific arrhythmias and delivering electrical defibrillation. To meet the requirements of portable defibrillators for high-precision ECG signal acquisition, rapid arrhythmia recognition, and high-reliability operation, this paper primarily introduces a low-power, multi-channel, 24-bit bioelectric analog front-end chip, the GX1298R. The GX1298R can replace the ADS1298 pin-for-pin and meets the ECG acquisition needs of portable AEDs.

Since the AED requires collecting standard 3-lead or 5-lead ECG signals to identify heart rhythms, the characteristic signals of these rhythms are faint and demand high-resolution acquisition to avoid misjudgment. The GX1298R features 24-bit lossless resolution with an input noise of 4.11 μVpp (0.64 μVrms) (BW=112.5Hz, G=6), enabling precise capture of weak ECG features. It incorporates a built-in programmable gain amplifier, internal reference, and integrated oscillator. Designed for ECG applications, it supports functions such as respiratory detection, right-leg drive, lead disconnection detection, pacemaker detection, and WCT. It can switch to internal clock and internal reference, thereby simplifying ECG peripheral circuits and significantly reducing the size, power consumption, and cost of the application product.

The GX1298R offers a data rate ranging from 15.625 SPS to 32k SPS, enabling faster acquisition of ECG signals to meet real-time monitoring needs for rapid cardiac state changes. Its exceptional low-noise performance prevents contamination of the original ECG signal by its own noise, delivering more accurate signal data and significantly improving diagnostic accuracy.

The main features of the GX1298R are as follows:

Data rate: 31.25 SPS to 32 kSPS

Programmable gain: 1, 2, 3, 4, 6, 8, or 12

Ultra-low input reference noise: 4.07μVpp (0.64μVrms) (BW=150Hz, G=6) CMRR: 120dB

Flexible power consumption modes: High-speed mode (HS), Low-power mode (LP), Ultra-low-power mode (ULP)

Low-power mode, with power consumption as low as 410µW (AVDD=3V, DVDD=1.8V, ODR=500SPS, G=6)

Built-in low-temperature coefficient reference; built-in clock with adjustable frequency and external output capability

Built-in right leg drive amplifier, lead disconnection detection, temperature sensor, test signal

Supports digital pacing detection

Adjustable data cache depth (1/2/4/8/16/32)

Offset/Gain Error Calibration Function

Power Supply Range: Analog Power Supply: 2.7V to 5.25V; Digital Power Supply: 1.8V to 5.25V

Flexible power-off and standby modes

SPI interface

Operating temperature range: -40°C to +85°C