Hardware design of GXSC GX5534 replacing CS5534 in high-precision analog acquisition card

In intelligent instruments and detection devices based on microcontrollers, the response to changes in input signals is very sensitive, so the selection of analog-to-digital converters has a significant impact on the performance of these devices.

Traditional 12 bit parallel interface AD converters are often unable to meet the measurement accuracy requirements of general instruments. Therefore, this article chooses a high-precision GXSC ADC, which can be used to design high-precision analog cards widely used in the industrial control field. And GXSC GX5534 can replace CS5534 100% without software and hardware adjustments, and requires less design resources.

The GXSC GX5534 is used in analog acquisition cards to provide the required speed, accuracy, low power consumption, and reliability. The GX5534 chip adopts charge balancing technology and an extremely low-noise programmable gain chopper stable measurement amplifier, with an output resolution of up to 24 bits. The chip uses a serial interface to communicate with the central processing unit, and the interface circuit is relatively simple. In addition, GX5534 has a complete self calibration system internally that can perform self calibration and system calibration, eliminating the zero point error and drift error of A/D itself.

The GX5534 chip integrates a programmable gain amplifier (PGA) and a low drift 2.5V reference voltage source, which enables precise measurement for bridge sensors. The output data rate of the device can be configured as 1.875, 3.75, 7.5, 15, 30, 60, 120, 440, 480, 909, 920, and 3840 SPS. Bipolar ± 2.375V to ± 2.625V analog power supply can be used, or a single 4.75V to 5.25V analog power supply can be used.

The main parameters of GX5534 are as follows:

Effective value noise: 16nV noise free bit at 7.5SPS (gain=64) and 22.37.5SPS (gain=1)

Offset drift: 5nV/℃ C (gain=64)

Gain source shift: 0.5ppm/C

2.5V internal reference voltage source, 5ppm/° C drift

• Integral nonlinearity: 3ppm

• Package: Provides 20/24 pin TSSOP