Issue link: https://resources.mouser.com/i/1442772
Nanopower means the LPV821 delivers an exceptional precision-to-power consumption ratio. This exceptional ratio means it is an ideal op-amp for applications that require the utilization of a limited-capacity power supply and battery current, but still must deliver high-performance amplification. Potential applications include battery voltage and current monitoring in portable applications, wireless sensing nodes, home and factory automation equipment, industrial sensors and detectors, field-deployed remote transmitters, battery packs, precision strain gauge and weigh scales, ongoing blood glucose monitoring, and other electrochemical cell applications. TI has extensive experience in designing systems covering analog and embedded processors. TI has reference designs available for supporting designs, including always ON low-power gas sensing with long battery life and micropower electrochemical gas sensors. Current monitoring may happen by placing an op-amp across a low resistance shunt resistor (RShunt) that is in series with the battery. The op-amp needs to be both precise and low power to ensure the correct current measurement while maximizing the battery life. The LPV821 is a suitable op-amp for this type of application Figure 2. The figure shows the LPV821 employed as a differential amplifier. Employment as a differential op-amp helps to reduce errors caused by the resistance value of the shunt resistor (RShunt). The high common-mode-rejection-ratio (CMRR, 125dBB, typ) of the LPV821 ensures it performs this function well. Like the always ON New York City, nanopower enables this part to support always-on applications. The low supply current decreases the external circuitry required to turn the amplifier on and off. 7 Figure 2: Low-Side, Always On Differential Current Sense employing Texas Instruments LPV821. (Source: Mouser Electronics) Conclusion Texas Instruments has a large portfolio spanning high-speed, precision, audio, and general purpose op-amps. Always ON sensing applications require high-precision nanopower op-amps. They help engineers extend their system's life with no battery change or recharging. Texas Instruments' LPV821 zero-drift nanopower op-amp allows designers to get some downtime and sleep knowing they have provided the perfect solution to any application that may require always ON sensing. Now, if only I can get Frank's song to stop playing on and on inside my head, maybe I can finally get a little sleep myself.