Domestic 24 bit 4-channel 140KSPS synchronous sampling analog-to-digital converter replaces ADS1274 for high-precision oscilloscope application

In the field of electronic measurement, high-precision oscilloscopes are tools for analyzing weak signals and wide dynamic range signals, widely used in integrated circuit testing, sensor calibration, aviation electronic equipment and other scenarios. This type of oscilloscope needs to achieve high-resolution capture of weak signal details, low-noise restoration of the true waveform of the signal, and wide dynamic range coverage of strong and weak signal coexistence scenarios. The GXSC 24 bit 4-channel 140KSPS synchronous sampling analog-to-digital converter GX1274 can match the high-precision and low-noise oscilloscope signal acquisition requirements.

A high-precision oscilloscope needs to distinguish small fluctuations in weak signals, and its noise level directly determines the detection ability of weak signals. The analog-to-digital converter GX1274 uses a high-order multi bit Delta sigma modulator to shape the in band noise and filter it out through an on-chip digital extraction filter, resulting in very low in band noise power. There are two types of on-chip digital filters to choose from: a high bandwidth FIR filter with an effective bandwidth of 90.6% of the Nyquist bandwidth and an in band ripple of less than ± 0.005dB; and a low latency SINC filter that can generate stable data output within 6 cycles and has better noise performance.

In order to adapt to different application scenarios, GX1274 can choose from four modes based on speed, accuracy, and power consumption requirements: High Speed (HS) mode, which has the fastest speed and can reach 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. GX1274 can be directly controlled using a PIN pin, without the need to compile registers, making it convenient for customers to use.

The characteristics of GX1274 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