GXSC ADC Replaces AD9643 in Smart Antenna Systems

Smart antenna systems incorporate core technologies such as array signal sampling, digital beamforming, adaptive spatial filtering, and multi-target tracking. They can optimize beam pointing in real time, suppress interference signals, and enhance spectrum utilization and link gain. Their beam accuracy, interference resistance, and communication capacity depend on the sampling accuracy, dynamic range, synchronization, and high-speed signal processing capabilities of the RF receive chain.

The front-end analog-to-digital converters (ADCs) in the system determine the signal fidelity of the array channels and the quality of beam formation. GXSC’s dual-channel 14-bit 250 MHz ADC features a high signal-to-noise ratio (SNR), ultra-wide spurious-free dynamic range (SFDR), low latency, and dual-channel synchronous sampling. It fully meets the requirements for multi-channel array sampling and high-bandwidth signal acquisition in smart antenna systems, making it the preferred component for the receive chains of mid-to-high-frequency smart antenna systems.

The GXSC ADC core employs a seven-stage differential pipeline architecture and integrates digital calibration logic and output error correction logic to achieve superior SNR and SFDR performance, aiming to provide solutions for low-cost, compact, wideband, and multifunctional communication applications. On the input side, this device supports bandwidth-adaptive input, allowing users to flexibly select the input frequency range. On the output side, it features a 14-bit LVDS parallel output, with data from both channels output in an interleaved or multiplexed manner. Regarding peripheral circuitry, this domestically produced analog-to-digital converter integrates a precision voltage reference and provides an input common-mode voltage, simplifying peripheral circuit design. Configuration is performed via a 3-wire SPI interface.

GXSC ADC Features:

1.8V analog/digital power supply

LVDS (ANSI-644 levels) and CMOS outputs

On-chip precision voltage reference

3-wire SPI interface

Sampling rate up to 250 MSPS

Typical SNR: 69.4 dBFS (185 MHz)

Typical SFDR: 80 dBc (185 MHz)

Input noise: -150.4 dBFS/Hz

Channel-to-channel isolation: 90 dB (100 MHz)

Total power consumption: 367 mW

Flexible analog input range: 1.4 Vpp to 2 Vpp

Maximum clock input frequency of 625 MHz, supporting 1:1 to 1:8 clock division modes

Available in a QFN64 package

Operating temperature range: -40°C to 85°C

The GXSC ADC utilizes proprietary patented technology to significantly optimize power consumption. Operating at a sampling rate of 250 MSPS, typical power consumption is only 367 mW. The chip also supports a power-down mode, in which power consumption is drastically reduced to 4.9 mW.