GXSC Analog-to-Digital Converter Replaces ADS4449 in Radar Systems

Modern radar technology is evolving toward wide bandwidth, high refresh rates, and multi-channel coordination. Traditional intermediate frequency sampling architectures face bottlenecks such as complex signal paths, significant signal loss, and insufficient real-time performance. Direct RF sampling architectures have emerged as the mainstream trend due to their advantages in simplifying signal paths and enhancing signal integrity. As the core component of RF direct sampling chains, analog-to-digital converters must deliver high-speed sampling, wide bandwidth coverage, high dynamic range, and multi-channel synchronization capabilities to meet radar systems‘ demands for precise capture of complex signals.

Radar systems require direct acquisition and conversion of antenna-received signals, bypassing traditional mixing stages to convert RF signals directly into digital data for subsequent processing by backend FPGAs/DSPs. GXSC‘s high-linearity four-channel 14-bit 250MSPS ADC delivers outstanding performance in RF-to-digital conversion. Each channel features a multi-stage differential pipeline ADC core with integrated output error correction logic. Every ADC offers high bandwidth and supports multiple user-selectable input ranges.

The GXSC ADC integrates a duty cycle correction circuit to stabilize the internal clock signal‘s duty cycle, ensuring consistently outstanding conversion performance. Conversion data is directly output via two pairs of cross-connected, multi-channel multiplexed 14-bit LVDS level interface circuits. The chip can be flexibly configured into a power-down mode as needed, significantly reducing power consumption. Configuration and control programming are accomplished through a four-wire SPI serial interface.

Key Advantages of the GXSC ADC:

- Plastic BGA144 package, compatible with reference model ADS4449

- Four-channel 250MSPS ADC

- Low power consumption, no heat sink required

- Integrated ADC clock duty cycle stabilizer (DCS)

- Internal ADC reference voltage source

- Single 1.8V power supply

 Programmable analog input range with programmable swing LVDS output

Peak-to-peak voltage input range: 1.4Vpp to 2.0Vpp, default: 1.75Vpp

Supports 1.8V or 3.3V serial four-wire SPI interface control

Flexible power-down modes

Operating temperature range: -55°C to +125°C

 Static Performance: DNL: -0.75/+0.75 LSB, INL: -0.40/+0.40 LSB

Differential Analog Input Bandwidth: 400MHz

Dynamic Performance:

-fin=90MHz, ENOB=11.4 bits, SNDR=70.3dBFS, SNR=70.6dBFS

-fin=140MHz, ENOB=11.2 bits, SNDR=69.1dBFS, SNR=69.5dBFS

-fin=220MHz, ENOB=11.2 bits, SNDR=69.2dBFS, SNR=69.4dBFS

-fin=350MHz, ENOB=10.6 bits, SNDR=65.8 dBFS, SNR=66.1 dBFS