The CMOS op amp is optimised for consumer and industrial equipment requiring high-speed sensing and measurement
The proliferation of the Internet of Things (IoT) in recent years has led to a significant increase in the number of electronic components used for advanced control in a variety of applications. This trend towards greater electronics density is leading to noisier environments, making it extremely difficult to implement designs with electromagnetic compatibility (EMC).Â
Over here, op amps play an important role because they quickly amplify small signals from sensors in many detection systems that provide safety. However, PCB design can be problematic for conventional op amps that are susceptible to oscillation due to capacitive loads (i.e. from wiring).
To mitigate noise issues common with conventional op amps, a 2 channel high-speed ground sense CMOS op amp, BD77502FVM has been launched that is optimised for consumer and industrial equipment requiring high-speed sensing for industrial measurement and control systems.
The newly released op amp belongs to the EMARMOUR series that features superior noise-tolerant op amps. It integrates two op amp devices that prevent oscillation (i.e. due to wiring) while providing high-speed amplification with slew rates up to 10V/µs and breakthrough immunity to electromagnetic interference (EMI).Â
The output voltage across the entire noise frequency band is limited to under ±20mV, which is 10x lower than a conventional op amp. High-speed signal amplification is now achievable without being affected by external noise or load capacitance when used in devices that output small signals such as sensors, thus improving reliability while simplifying circuit designs.
Key Features
The BD77502FVM, which expands the EMARMOUR lineup that delivers unmatched noise tolerance, builds upon the 1ch ground sense CMOS op amp BD77501G widely adopted in the industrial equipment market by offering high-speed operation and preventing oscillation due to load capacitance. The 2ch design also supports market demands for more compact board designs.
1. No oscillation and high-speed op amps that minimise design time related to load capacitance
Unlike standard op amps that can be difficult to use due to restrictions imposed on the wiring and peripheral components resulting from instability caused by load capacitance, the new op amp prevents oscillation to ensure stable operation and facilitate application design.
2. Superior noise immunity facilitates noise design requirementsÂ
The output voltage of conventional products can fluctuate by ±200mV or more across the entire noise frequency band. But BD77502FVM op amp achieves unprecedented noise immunity that limits variation to less than ±20mV. This eliminates the need for filter circuits for each noise frequency, reducing the noise design resources for sensors (which play an important role in a variety of systems) while improving system reliability.
3. Eliminates several parts required for noise suppressionÂ
The BD77502FVM provides a noise immunity that eliminates the need for external noise countermeasure components conventionally required for standard products (i.e. RC filters for the power supply, input and output pins).Â
Application Examples
- Facility management equipment such as abnormal current and gas detectors
- Motors requiring high-speed control (signal transmission)
- Inverter control equipment
- Pre-drive buffers for driving transistors
…and other industrial and consumer applications requiring high-speed signal transmission and amplification without worrying about load capacitance.
The BD77502FVM is in mass production and available from ROHM Semiconductor.
