Application scheme of GXSC24 bit 256KSPS8 channel synchronous sampling analog front-end chip software and hardware replacement ADS1274 in multi lead electrocardiogram machine

A multi lead electrocardiogram machine is an important tool for medical diagnosis, which can simultaneously record electrocardiogram signals from multiple parts of the human body. The design scheme of a multi lead electrocardiogram machine usually includes five modules: input circuit, electrocardiogram amplification, signal processing, and recording display. The electrocardiogram signal has the characteristics of weakness and susceptibility to interference, which requires strict control over the resolution, noise suppression capability, and multi-channel synchronization of the front-end signal acquisition equipment. GXSC, a 24 bit 144kSPS, 4-channel synchronous sampling analog front-end chip, can meet the needs of multi lead electrocardiographs.

The GXSC analog front-end supports a data sampling rate of up to 144kSPS, which enables extremely fine quantization of input analog signals, effectively improving the accuracy and system resolution of multi lead electrocardiographs.

Four mode options: High Speed (HS) mode, with the fastest speed, can achieve 144kSps with a 37MHz clock and a -3dB bandwidth of 70kHz; High precision (HR) mode, with the highest accuracy, SNR up to 111.7dB, THD up to -122.9dB, and power consumption of only 20.8mW/channel; Low power (LP) mode, with the same output rate as HR mode but almost halved power consumption; Low speed (LS) mode, suitable for low-speed acquisition, with power consumption as low as 2.7mW/channel. And the chip is directly controlled by PIN pins, without the need to compile registers, making it convenient for customers to use.

Its characteristics are as follows:

4-channel synchronous sampling, data rate up to 144kSps

High bandwidth FIR filters and low latency SINC filters are optional

Low power consumption: HS mode: 34.0mW/channel;

HR mode: 20.8mW/channel;

LP mode: 10.9mW/channel;

LS mode: 2.7mW/channel;

Rail to rail input common mode level

Common mode rejection ratio: 116dB

Analog power supply 5V; digital power supply 1.8V

IO power supply: 1.8V~3.3V

SPI or frame synchronization interface, supporting daisy chain mode

ESD level: HBM ± 2kV, CDM ± 2kV; Latch up ± 600mA

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