The AD636 is a low power monolithic IC that performs true rms-to-dc conversion on low level signals. It offers performance that is comparable or superior to that of hybrid and modular converters costing much more. The AD636 integrates a current mirror, squarer, divider, and absolute value circuit to provide 0.5% maximum error (AD636K) or 1.0% maximum error (AD636J) true rms-to-dc conversion. The AD636's input signal voltage range is 100 mV to 10 V, and it can be operated from a single or dual supply. The AD636's power dissipation is only 800 μA quiescent current, making it an ideal solution for portable and battery-powered applications.