Low-Power ADCs Boast High Integration Levels

A family of 24-bit, low-noise temperature-measurement analog-to-digital converters (ADCs) feature very low power consumption and high integration levels. The ADS1248 and ADS1247 integrate dual matched-current digital-to-analog converters (DACs), a low-drift internal reference, oscillator, temperature sensor, burnout detection, and eight general-purpose I/Os. Their data rate is 2 ksamples/s and power dissipation is 2.56 mW. The programmable-gain amplifier has a noise level of only 40 nV at a gain of 128. The ADS1248 has four differential or seven single-ended inputs. The ADS1247 has 2 differential or three single-ended inputs. The devices include 50/60-Hz simultaneous rejection mode. The ADCs provide an easy-to-use, low-power front-end solution for temperature measurement (RTDs, thermocouples, thermistors), flow/pressure measurement, and industrial process control. The ADS1248 and ADS1247 are available now in a TSSOP-20 package. In 1000-piece quantities, the ADS1248 costs $4.95, and the ADS1247 costs $4.45. For applications requiring a smaller package and lower cost, the single-channel ADS1246 provides a reduced feature set in a TSSOP-16 package for $3.45. TEXAS INSTRUMENTS INC., Dallas, TX. (800) 477-8924.