Replacing the AD7982 with the GXSC ADC in Automated Test Equipment

Automated test equipment primarily performs automated testing tasks such as acquiring device electrical parameters, verifying signal accuracy, and screening for performance consistency. The analog front-end, which captures device performance, is a critical component for ensuring automated quality inspection and parameter calibration of precision devices. This article recommends using a domestically produced 18-bit, 1 MSPS differential-input analog-to-digital converter to replace the AD7982 in automated test equipment.

In testing scenarios involving precision components and micro-modules, response signal amplitudes are weak and parameter differences are minute, requiring an ADC with high resolution, high linearity, and low noise to accurately capture even the smallest parameter deviations. This domestically produced ADC is an 18-bit, high-precision successive approximation register (SAR) ADC featuring a high-speed sampling rate of 1 MSPS and high-precision quantization with no lost codes. Compared to standard ADCs, it offers comprehensive upgrades in resolution, linearity, and noise suppression.

This domestically produced ADC integrates a low-power, high-speed, 18-bit sampling ADC and a multifunctional serial interface. It samples the voltage difference between the IN+ and IN- pins on the rising edge of the CNV signal. The signals on the two input pins are typically out of phase, with a voltage swing ranging from 0 V to VREF. The reference voltage VREF is supplied externally and can be independent of the power supply voltage VDD. The ADC’s total power consumption is directly proportional to the sampling rate.

Product Features:

Single-supply operation: 2.5 V

Logic interface voltage: 2.5 V, 3 V, 5 V

True differential analog input range: VREF

18-bit resolution, no lost counts; sampling rate: 1 MSPS

INL: Typical value of 1.2 LSB (VREF = 5 V)

Dynamic range: 99 dB (VREF = 5 V)

SNR: 98.5 dB (fIN = 1 kHz, VREF = 5 V)

SNDR: 98 dB (fIN = 1 kHz, VREF = 5 V)

THD: -119 dB (fIN = 1 kHz, VREF = 5 V)

Serial Interface: SPI/QSPI/MICROWIRE compatible

No pipeline delay

Low Power Consumption: 8.3 mW (1 MSPS, VDD only); 11.9 mW (1 MSPS, total power); 522 W (10 kSPS, total power)

Packages: MSOP10 3 mm × 3 mm, DFN10 3 mm × 3 mm