GXSC Single-Channel 14-Bit 125 MSPS Digital-to-Analog Converter Compatible with AD9764 for Communication Base Stations

The signal quality of the transmission link in a communication base station determines the network coverage, communication stability, and user experience. Among these, the digital-to-analog converter (DAC) serves as a critical component in the base station‘s transmission link, converting digital signals to analog signals. Its resolution, conversion speed, linearity, and noise performance affect the fidelity of the RF signal. This paper recommends the use of the GXSC 14-bit resolution, broadband high-performance, low-power CMOS DAC. The chip features a plastic TSSOP28 package, enabling pin-to-pin replacement of the AD9764.

The GXSC analog-to-digital converter delivers outstanding AC and DC performance while supporting an update rate of up to 125 MSPS. Fabricated with advanced CMOS technology and featuring a segmented current source architecture, it minimizes stray elements and enhances dynamic performance, perfectly meeting the signal conversion requirements of communication base station transmit chains.

The GXSC analog-to-digital converter integrates an edge-triggered input latch and a 1.25V temperature-compensated bandgap reference to provide a complete monolithic DAC solution. Differential current output supports both single-ended and differential applications. In differential output mode, the matching between the two current outputs affects dynamic performance. The current output can be directly connected to an output resistor to provide two complementary single-ended voltage outputs or directly output to a transformer.

The GXSC analog-to-digital converter features on-chip reference and control amplifiers that deliver maximum precision and flexibility. These amplifiers can be driven by either an internal reference voltage or various external reference voltages. The internal control amplifier provides a wide adjustment range (>10:1), enabling the chip‘s full-scale current to be adjusted within the range of 2mA to 20mA while maintaining excellent dynamic performance. Consequently, the GXSC analog-to-digital converter can operate at lower power levels or be adjusted within a 20dB range to provide additional gain variations.

Advantages of GXSC Analog-to-Digital Converter Products:

Pin-to-pin compatible with AD9764

Single-channel 125MSPS, 14-bit resolution DAC

Differential current output: 2mA to 20mA

Power consumption: 88mW (@3.3V)

Single 3.3V power supply

On-chip 1.25V reference

Edge-triggered latch

Sampling rate: 125 MSPS

The package is a plastic TSSOP28

Static Performance: DNL -1.5/+1.5 LSB, INL -2.5/+2.5 LSB