GXSC ADC as a Drop-In Replacement for ADS4449 in RF Signal Analyzers

In the communications field, RF signal analyzers are instruments used to analyze and test the performance of RF signals. They integrate multiple functions including spectrum analysis, interference analysis, antenna and feeder analysis, and power testing. These instruments perform spectrum analysis on received RF signals, display signal spectral distribution and frequency components, help users locate and identify interfering signals, measure the electrical characteristics of active and passive devices, and conduct precise power measurements.

As comprehensive test instruments, RF signal analyzers typically offer a high degree of flexibility and scalability, allowing customization and configuration according to different testing requirements. Generally, RF signals and wideband modulated signals have large instantaneous bandwidths, requiring analog-to-digital converters (ADCs) with high-speed sampling capabilities to achieve alias-free acquisition of wideband signals. The GXSC high-linearity quad-channel 14-bit 250MSPS ADC delivers exceptional performance in RF signal digitization and can serve as a pin-to-pin replacement for the ADS4449 to meet the precision testing demands of signal analyzers.

Each channel of the GXSC ADC incorporates a multi-stage, differential pipelined architecture with integrated output error correction logic. Every ADC features high bandwidth and supports multiple user-selectable input ranges. The chip integrates a duty-cycle correction circuit that stabilizes the duty cycle of the internal clock signal, ensuring that the ADC consistently delivers excellent conversion performance. Converted data is output directly via two pairs of cross-interleaved, multi-channel multiplexed 14-bit LVDS interface circuits. The device can be flexibly configured in power-down mode as needed to significantly reduce power consumption, with setup and control programming accomplished through a 4-wire SPI serial interface.

GXSC ADC Product Advantages:

Plastic BGA144 package, compatible with the reference model ADS4449

Quad-channel 250MSPS ADC

Low power consumption, no heatsink required

Integrated internal clock duty-cycle stabilizer (DCS)

Internal ADC reference voltage source

Single 1.8V power supply

Programmable analog input range and programmable swing LVDS outputs

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

Supports 1.8V or 3.3V serial 4-wire SPI interface control

Flexible power-saving power-down modes

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

Static performance: DNL: -0.75/+0.75 LSB, INL: -4.0/+4.0 LSB

Differential analog input bandwidth: 400MHz

Dynamic performance:

fin = 90MHz: ENOB = 11.4 Bit, SNDR = 70.3 dBFS, SNR = 70.6 dBFS

fin = 140MHz: ENOB = 11.2 Bit, SNDR = 69.1 dBFS, SNR = 69.5 dBFS

fin = 220MHz: ENOB = 11.2 Bit, SNDR = 69.2 dBFS, SNR = 69.4 dBFS

fin = 350MHz: ENOB = 10.6 Bit, SNDR = 65.8 dBFS, SNR = 66.1 dBFS