AD780（2.5 V/3.0 V,High Precision Reference）IntroductionThe AD780 is an ultrahigh precision band gap reference voltage that provides a 2.5 V or 3.0 V output from inputs between 4.0 V and 36 V.Low initial error and temperature drift combined with low output noise and the ability to drive any value of capacitance make the AD780 the ideal choice for enhancing the performance of high resolution analog-to-digital converters (ADCs) and digital-to- analog converters (DACs), and for any general-purpose precision reference application. A unique low headroom design facilitates a 3.0 V output from a 5.0 V 10% input,providing a 20% boost to the dynamic range of an ADC over performance with existing 2.5 V references.The AD780 can be used to source or sink up to 10 mA, and can be used in series or shunt mode, thus allowing positive or negative output voltages without external components.This makes it suitable for virtually any high performance reference application. Unlike some competing references, the AD780 has no region of possible instability.The part is stable under all load conditions when a 1μF bypass capacitor is used on the supply.The AD780 provides an output voltage that varies linearly with temperature on its temperature output pin, enabling users to configure the part as a temperature transducer while maintaining a stable 2.5 V or 3.0 V output.The AD780 is a pin compatible performance upgrade for the LT1019(A)-2.5 and the AD680. Low power applications target the latter.The AD780 is available in three grades in PDIP and SOIC packages. The AD780AN, AD780AR, AD780BN, AD780BR,and AD780CR are specified for operation from -40°C to 85°C.FeaturePin programmable 2.5 V or 3.0 V outputUItralow drift: 3 ppm/°C maxHigh accuracy: 2.5 V or 3.0V ±1 mV maxLow noise: 100 nV/√HzNoise reduction capabilityLow quiescent current: 1 mA maxOutput trim capabilityPlug-in upgrade for present referencesTemperature output pinSeries or shunt mode operation (±2.5 V,±3.0 V)Appearance
