High-speed op-amp removes oscillation due to load capacitances

ROHM has released a high-speed ground sense CMOS op-amp, BD77501G, optimised for industrial and consumer equipment needing high-speed sensing, such as anomaly detection systems employed in measurement and control equipment along with sensors that operate with very small signals.

The company has developed the EMARMOUR series of op-amps and comparators for the automotive and industrial markets due to its superior noise immunity that allows users to lessen design resources to address noise issues. This time, the company has extended the line up by adding a new high-speed type excellent for anomaly detection that stops oscillation over the complete load capacitance range.

The device is claimed to be the industry’s first op-amp that not only supports high-speed amplification (high slew rate: 10V/us) needed in anomaly detection and other systems but also totally eradicates oscillation caused by load capacitance (i.e. wiring). Unlike conventional high-speed op-amps that could become unstable due to load-capacitance-induced oscillation, the new product provides stable operation with no unwanted oscillation. Also, whereas the output voltage for conventional products can vary by ±200mV or more over the whole noise frequency band, the device gives unprecedented EMI Immunity that limits variation to less than ±20mV (1/10th). This allows high-speed signal amplification without being influenced by load capacitance or external noise when installed in the late stages of sensor applications, improving reliability and decreasing design time.