Tiny 16-Bit ADCs Include Internal Reference

A pair of 16-bit sigma-delta analog-to-digital converters (ADCs) integrate a precision reference (2 ppm/°C typical, 10 ppm/°C maximum) in a 3- by 3-mm DFN package. The elimination of the need for an external reference and the inclusion of an on-board oscillator make the ADCs well-suited for space-constrained applications. The converters guarantee 16-bit no-missing-code resolution with a maximum of 60 conversions per second, suitable for measuring temperature, pressure voltage, or other low-frequency sensor signals. Operating from a single 2.7- to 5.5-V supply and using the internal 1.25-V reference, the LTC2460 can measure a single-ended input from 0 to 1.25 V, and the LTC2462 can measure a differential input of up to ±1.25 V. The devices exhibit 16-bit dc performance of 1 LSB (typical) integral nonlinearity error, 2.2 µV rms transition noise, and 0.25% gain error (maximum). After each conversion, the ADC enters a shutdown mode, reducing supply current to less than 1.5 mA (maximum). In sleep mode that levels drops to less than 2 µA. A proprietary input sampling network reduces the dynamic input current to less that 50 nA. Besides the 12-pin DFN package, the ADCs are available in an MSOP package. Both commercial and industrial temperature grade versions are available. Prices start at $1.65 each in quantities of 1000. LINEAR TECHNOLOGY CORP., Milpitas, CA. (408) 432-1900.