SBOS932C January 2020 – March 2021 THP210
The stability of the amplifiers is of key importance when designing application circuits with fully differential amplifiers. This stability becomes especially important when driving capacitive loads, such as the input for successive-approximation-register (SAR) analog-to-digital converters (ADCs). A trade-off is made between the bandwidth of an amplifier and keeping power consumption low; in many cases, FDAs are not unity gain stable. Currently, many FDAs are primarily designed to support high-speed ADCs, and thus, are typically decompensated. This decompensation comes with the drawback that the noise performance degrades because of noise gain peaking. Additional components and compensation techniques are required to handle these challenges and prevent potential instability of the FDA. For detailed analysis of how stability is defined and affected, see TI Precision Labs – Fully Differential Amplifiers – FDA Stability and Simulating Phase Margin.
The THP210 is unity-gain stable; therefore, this device can be used in gain configurations with gains > 1, and also in attenuating configurations with gains < 1, without requiring compensation techniques and sacrificing dynamic performance. This device can be of prime use for applications that need to interface large input signals to the low-voltage ADC domain.