Amplifier and Data Converter Selection Guide (Rev. B

Voltage References81Precision Voltage and CurrentReferencesTI’s family of voltage and current referencesincorporates state-of-the-art technology tooffer stable, high-precision, high-performancereferences in tiny packages.Series Voltage ReferencesSeries voltage references are known forexcellent accuracy and stability overtemperature. Typically three terminaldevices, series voltage references are oftenused to provide stable reference voltagesfor ADCs and microcontrollers.The REF29xx, REF30xx, REF31xx and REF32xxare TI’s newest available families of precision,low-power, low-dropout, series voltagereferences in tiny SOT23-3 packages. Driftspecifications range from 100ppm/°C to lessthan 10ppm/°C. Small size and low powerconsumption (100µA typ) make them ideal forportable and battery-powered applications.These voltage references are stable with anycapacitive load and can sink/source a minimumof up to 10mA of output current and arespecified for the temperature range of –40°Cto +125°C.Shunt Voltage ReferencesShunt voltage references are precision diodesdesigned to offer good accuracy at extremelylow power. These devices require a currentsource, typically a supply voltage and pull-upresistor to keep forward biased.The REF1112 is a 1µA, two-terminalreference diode designed for highaccuracy with outstanding temperaturecharacteristics at low operating currents.Precision thin-film resistors result in 0.2%initial voltage accuracy and 50ppm/°Cmaximum temperature drift. The REF1112 isspecified from –40°C to +85°C, with operationfrom 1µA to 5mA, and is offered in aSOT23-3 package.Voltage ReferencesCurrent ReferencesMany applications require the use of aprecision current source or current sink. TheREF200 combines three circuit building-blockson a single monolithic chip—two 100µAcurrent sources and a current mirror capableof being used as a current source or sink.Integrated Op Amp and VoltageReferencesFor applications requiring an op amp plusvoltage reference or comparator plus voltagereference, TI has an offering of integratedfunction voltage references. The TLV3011 andTLV3012 are low-power, (5µA) 6µs propagationdelay comparators with an integrated shuntvoltage reference.See pages 24 -25 for comparatorand integrated voltage referencespecifications➔30ppm/°C Drift, 3.9µA, Series Voltage References in SC70REF3312, REF3318, REF3320, REF3325 REF3330, REF3333Get samples, datasheets and evaluation modules at: www.ti.com/sc/device/PARTnumber (Replace PARTnumber with REF3312, REF3318, REF3320, REF3325, REF3330 and REF3333)Key Features• microSize packages: SC70-3, SOT23-3• Low supply current: 3.9µA (typ)• Low temperature drift: 30ppm/°C (max)• High output current: ±5mA• High accuracy: ±0.1%Applications• Portable battery powered equipment• Handheld monitoring• Data acquisition systems• Medical equipment• Test equipmentThe REF33xx combines the excellent performance of a 30ppm/°C precision (0.1% accuracy)voltage reference with ultra-low quiescent current (5µA max) and space-saving SC70micro-packaging to offer a design for performance portable applications. The REF33xx cansink and source up to 5mA and is specified over the industrial temperature range of –40°Cto +125°C.2.5VV INREF3112V OUT = 1.25V0.1µFV REFADS8324V CC+1µF to 10µF5Ω2.5V SupplyV S+1µF to 10µFGND0V to 1.25V+InCSMicrocontroller–InD OUTGNDDCLOCKA low power REF33xx reference current. *Expected REF33xx release date, 4Q 2007Texas Instruments 3Q 2007Amplifier and Data Converter Selection Guide