GXSC ADC Compares to AD7699 in GPS Systems

GPS satellite positioning systems primarily achieve high-precision position, velocity, and time information output by receiving satellite RF signals, environmental data, and signal demodulation. The device collects analog parameters via multiple sensors, performs fusion calibration, and ultimately outputs accurate and stable position information to enable static positioning and dynamic tracking.

Since GPS positioning systems require high resolution and multi-channel synchronous data acquisition, the AD7699 is commonly used. GXSC’s 8-channel, 16-bit, 500 kSPS analog-to-digital converter can fully replace the AD7699, perfectly meeting the GPS system’s requirements for synchronous acquisition of multi-source analog signals, attitude data calibration, and overall system status monitoring.

The GXSC ADC operates on a single power supply and integrates all the circuits required for a multi-channel, low-power data acquisition system, including a true 16-bit SAR ADC with no lost codes, an 8-channel low-crosstalk multiplexer, an internal 4.096V low-drift reference voltage source and buffer, a temperature sensor, an optional single-pole filter, and a multi-channel sequencer. The chip uses an SPI interface to write configuration registers and receive conversion results.

GXSC ADC Features:

Single-supply operation: 5V

Logic interface voltage: 1.8V to 5V

8-channel multiplexer, supporting unipolar single-ended, differential, and pseudo-bipolar inputs

Sampling rate: 500 kSPS

INL: Maximum 2.5 LSB

Dynamic range: 92 dB

SNDR: 90.5 dB (fIN = 1 kHz)

THD: -102 dB (fIN = 1 kHz)

Analog input range: 0 V to VREF (VREF can be as high as VDD)

Serial interface compatible with SPI/QSPI/MICROWIRE/DSP

Multiple reference source types: internal 4.096V reference source, external buffered reference source (up to 4.096V), external reference source (up to VDD)

Channel sequencer, selectable single-pole filter, busy indicator

No pipeline delay, SAR architecture

Low power consumption: 18 mW (500 kSPS), 3.5 μW (100 SPS)

The SPI interface is powered by a dedicated VIO supply; its power consumption is proportional to the sampling rate

Available in QFN20 and WLCSP20 packages

Optimal operating temperature range: -40°C to 125°C