Ultra-tiny 16-bit ADC family's 0.5uA shutdown current ideal for portable sensor applications
(Product News, 02 May 2008 )
Linear Technology Corporation introduces the LTC2451 and LTC2452, a pair of 16-bit delta sigma ADCs with 0.5uA (max) shutdown current in ultra-tiny 3mm x 2mm DFN packages. Their low power, tiny size, and guaranteed 16-bit no missing code resolution makes these ADCs ideal for battery-powered applications such as remote sensors. Operating from a single 2.7V to 5.5V supply, these ADCs are designed to measure single-ended or differential sensors via either I2C or SPI serial interfaces. The LTC2451 communicates via I2C and can measure a single-ended input between 0V to VCC, whereas LTC2452 communicates via SPI and is capable of measuring a differential input up to ±VCC.
The LTC2451 and LTC2452 join the previously released LTC2450 (SPI, single-ended input) and LTC2453 (I2C, differential input), thereby offering a complete ultra-tiny 16-bit ADC family.
The versatile LTC2451/LTC2452 achieve excellent 16-bit DC performance of 2LSB integral nonlinearity error, 1.4uVRMS transition noise and 0.01% gain error. These ADCs have an internal oscillator and allow up to 60 conversions per second, making it easy to measure temperature, pressure, voltage, or other low-frequency sensor outputs. The LTC2451 draws 0.7mA (max) supply current and the LTC2452 1.2mA (max) at the 60Hz maximum sample rate. After each conversion, the ADC enters a shutdown mode, reducing supply current to less than 0.5uA (max). By sampling only occasionally, as many portable sensors do, the supply current is dramatically reduced. For example, the LTC2451/LTC2452 dissipate just 40uW from a 3V supply when sampling the ADC only once per second. The LTC2451/LTC2452 also incorporate a proprietary input sampling network that reduces the dynamic input current to less than 50nA, making a wide range of external input protection and filter circuits possible.
