Analog Devices Inc./Maxim Integrated

The LTC2401/LTC2402 are 1- and 2-channel 2.7V to 5.5V micropower 24-bit analog-to-digital converters with an integrated oscillator, 4ppm INL and 0.6ppm RMS noise. These ultrasmall devices use delta-sigma technology and a new digital filter architecture that settles in a single cycle. This eliminates the latency found in conventional ΔΣ converters and simplifies multiplexed applications.Through a single pin, the LTC2401/LTC2402 can be configured for better than 110dB rejection at 50Hz or 60Hz ±2%, or can be driven by an external oscillator for a user defined rejection frequency in the range 1Hz to 120Hz. The internal oscillator requires no external frequency setting components.These converters accept an external reference voltage from 0.1V to VCC. With an extended input conversion range of –12.5% VREFto 112.5% VREF(VREF= FSSET– ZSSET), the LTC2401/LTC2402 smoothly resolve the offset and overrange problems of preceding sensors or signal conditioning circuits.The LTC2401/LTC2402 communicate through a 2- or 3-wire digital interface that is compatible with SPI and MICROWIRE™protocols.ApplicationsWeight ScalesDirect Temperature MeasurementGas AnalyzersStrain-Gage TransducersInstrumentationData AcquisitionIndustrial Process Control

The LTC2412 is a 2-channel differential input micropower 24-bit No Latency ∆Σ™analog-to-digital converter with an integrated oscillator. It provides 2ppm INL and 0.16ppm RMS noise over the entire supply range. The two differential channels are converted alternately with channel ID included in the conversion results. It uses delta-sigma technology and provides single conversion settling of the digital filter. Through a single pin, the LTC2412 can be configured for better than 110dB input differential mode rejection at 50Hz or 60Hz ±2%, or it can be driven by an external oscillator for a user defined rejection frequency. The internal oscillator requires no external frequency setting components.The converter accepts any external differential reference voltage from 0.1V to VCCfor flexible ratiometric and remote sensing measurement configurations. The full-scale differential input range is from –0.5VREFto 0.5VREF. The reference common mode voltage, VREFCM, and the input common mode voltage, VINCM, may be independently set anywhere within the GND to VCC. The DC common mode input rejection is better than 140dB.The LTC2412 communicates through a flexible 3-wire digital interface which is compatible with SPI and MICROWIRE protocols.ApplicationsDirect Sensor DigitizerWeight ScalesDirect Temperature MeasurementGas AnalyzersStrain-Gage TransducersInstrumentationData AcquisitionIndustrial Process Control6-Digit DVMs