application-note · English
ADC Voltage Reference Buffer Optimization Reference Design for High-Performance DAQ Systems
This Texas Instruments reference design (TIDA-01055, document TIDUDE2A) presents an optimized two-stage composite voltage reference buffer for driving the REF pin of an 18-bit, 2-MSPS SAR ADC (ADS9110) in high-performance DAQ systems. The design uses a REF5040 4.096 V reference combined with an OPA378 precision op-amp and an OPA837 high-speed op-amp in a composite configuration, achieving a system ENOB of 15.77 bits at 1.94 W total power—a 22% power improvement over the conventional OPA625-based approach. The document covers stability, noise, power, and transient analysis via TINA-TI simulation, hardware jumper configuration, PCB layout recommendations (thick versus thin trace comparison), and measured performance results across multiple buffer and reference options.