GXSC Digital-to-Analog Converter Replaces AD9764 for Instrumentation Applications

In the field of instrumentation, the precise conversion between analog and digital signals is a critical step in ensuring measurement accuracy and signal processing reliability. Digital-to-analog converters (DACs) are widely used in scenarios such as instrumentation where digital signals need to be converted into analog signals. Typical performance metrics include the following:

Resolution: The smallest voltage change that an analog-to-digital converter can distinguish. Higher resolution results in greater conversion accuracy.

Linearity: The deviation between the actual output of the digital-to-analog converter and the ideal output. Higher linearity results in more accurate conversion.

Conversion speed: The time required for a digital-to-analog converter to complete a single conversion. The faster the conversion speed, the more timely the system response.

In response to the aforementioned requirements, this paper introduces the GXSC, a 14-bit resolution, broadband high-performance, low-power CMOS digital-to-analog converter. With its outstanding AC and DC performance, along with support for an update rate of up to 125 MSPS, this device can be pin-to-pin compatible with the AD9764 for applications in communication systems, base stations, ADSL/HFC modems, and instrumentation. Its high dynamic range and low-power characteristics make it particularly suitable for portable devices and industrial-grade applications.

The GXSC digital-to-analog converter is manufactured using advanced CMOS technology and features a segmented current source architecture. This fabrication process not only minimizes stray elements but also enhances dynamic performance. It integrates edge-triggered input latches and a 1.25V temperature-compensated bandgap reference, offering a complete monolithic digital-to-analog conversion solution. Differential current output supports both single-ended and differential applications. In differential output mode, the matching between the two current outputs impacts dynamic performance. The current output can be directly connected to an output resistor to provide two complementary single-ended voltage outputs or directly driven to a transformer.

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

Advantages of GXSC Digital-to-Analog Converter Products:

The package adopts plastic TSSOP28, compatible with AD9764.

Single-channel 125 MSPS 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 latching

Sampling rate: 125 MSPS

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