MILPITAS, CA - April 23, 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 V_CC, whereas LTC2452 communicates via SPI and is capable of measuring a differential input up to ±V_CC.

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, 1.4uV_RMS 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.

The LTC2451 and LTC2452 are each offered in 8-pin ultra-tiny 3mm x 2mm DFN packages. They are available today in both commercial and industrial temperature grade versions today. Pricing for the LTC2451 begins at $1.15 and the LTC2452 at $1.25, each in 1,000-piece quantities.

LTC245x Ultra-Tiny ADC Family

Summary of Features: LTC2451/LTC2452 ±VCC Differential Input Range (LTC2452/LTC2453) 0V to VCC Single-Ended Input Range (LTC2450/LTC2451) I2C-Compatible 2-Wire Interface (LTC2451/LTC2453) SPI-Compatible 3-Wire Interface (LTC2450/LTC2452) Extremely Low 50nA Dynamic Input Current Ultra-Tiny 3mm × 2mm DFN Package 2LSB INL, No Missing Codes 4LSB Full-Scale Error Single Supply 2.7 to 5.5V Operation 1.4uVRMS Noise Low Power:        700uA at 60Hz Output Rate (LTC2451)        10uA at 1Hz Output Rate        <1uA Sleep Current Internal Oscillator – No External Components Required Single Conversion Settling Time for Multiplexed Applications Single Cycle Operation with Auto Shutdown 60Hz Conversion Rate

Complete SPI/I2C Single-Ended/Differential Ultra-Tiny 16-Bit ADC Family Click Photo for High-Res Image