Six channel 16 bit 250kSPS synchronous sampling analog-to-digital converter GX7656 replaces AD7656 for application in substation status monitoring

In the power system, substations are nodes for energy conversion and distribution, and their equipment operation status directly determines the safety and stability of the power grid. The substation status monitoring system needs to collect real-time parameters such as voltage, current, temperature, and vibration of core equipment such as transformers, circuit breakers, and transformers, in order to timely detect potential faults such as insulation aging, poor contact, and mechanical wear, and avoid sudden power outages.

The substation environment presents challenges such as strong electromagnetic interference, wide temperature fluctuations, and the need for multi parameter synchronous acquisition. This article recommends using the six channel 16 bit 250kSPS synchronous sampling analog-to-digital converter GX7656, which is equipped with six 16 bit fast, low-power successive approximation ADCs and supports six channel synchronous sampling. It can replace AD7656 with PIN TO PIN to meet the monitoring needs of the substation.

GX7656 utilizes CONVST signals and internal oscillators to control the conversion process and data acquisition. The three CONVST pins allow for independent synchronous sampling of three pairs of ADCs or synchronous sampling of six channels. GX7656 supports high-speed parallel mode or high-speed serial mode, configured through different connection modes of hardware pins. This function creates various connection conditions for the interface connection between the device and the microprocessor or DSP. In parallel mode, the GX7656 can achieve a maximum sampling rate of 250kSPS.

Wide temperature operation and low-power design, fully adapted to harsh environments in substations, GX7656 provides a working temperature range of -40 ℃~+125 ℃, with a working power consumption of only 110mW (internal reference). It is powered by a 5V power supply and can support the conversion of true bipolar input signals of ± 10V and ± 5V. At the same time, the ADC also has an on-chip reference source, which can simplify the application circuit design. Its main characteristics are as follows:

6 independent ADCs

True bipolar analog input

• Input signal range: ± 10V/5V

• High conversion rate: 250kSPS

Low power consumption: 110mW (250kSPS, 5V power supply)

• On chip reference voltage source and buffer

Parallel and serial interface modes

• High speed serial interface compatible with SPI interface protocol

64 pin LQFP package