Hardware Design of GXSC GX5534 Replacing CS5534 in High Precision Analog Acquisition Card

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

The traditional 12-bit parallel interface AD converter usually can not meet the general instrumentation measurement accuracy requirements, therefore, this paper selects a high-precision GXSC ADC, which can be designed widely used in the field of industrial control of high-precision analog card. Moreover, the GXSC GX5534 can replace the CS5534 100% without hardware and software adjustments and requires less design resources.

GXSC GX5534 for analog acquisition card can provide the required speed, accuracy, low power consumption and reliability, GX5534 chip using charge balance technology and very low noise programmable gain chopper stabilization measurement amplifier, the output resolution of up to 24-bit, the chip adopts the serial interface and the central processor for communication work, the interface circuit is relatively simple. In addition, the GX5534 has a complete internal self-calibration system can be self-calibrated and system calibration to eliminate the zero error and drift error of the A/D itself.

The GX5534 chip integrates a programmable gain amplifier (PGA) and a low-drift 2.5V reference voltage source, which enables accurate measurements for bridge sensors. Output data rates from the device can be configured to 1.875, 3.75, 7.5, 15, 30, 60, 120, 240, 480, 960, 1920, and 3840 SPS, and can be supplied from a bipolar ±2.375V to ±2.625V analog power supply or from a single 4.75V to 5.25V analog power supply.

The GX5534‘s main parameters are as follows:

- RMS Noise: 16nV at 7.5SPS (Gain=64) Noise-free bit at 22.37.5SPS (Gain=1)

- Offset drift: 5nV/°CC (gain=64)

- Gain source shift: 0.5ppm/C

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

- Integral nonlinearity: 3ppm

- Package: 20/24-pin TSSOP available