LTC2497 16-Bit 8-/16-Channel DS ADC with Easy Drive Input Current Cancellation and I2C Interface FeaTuresDescripTion n Up to Eight Differential or 16 Single-Ended Inputs The LTC®2497 is a 16-channel (eight differential), 16-bit, n Easy DriveTM Technology Enables Rail-to-Rail No Latency DSTM ADC with Easy Drive technology and Inputs with Zero Differential Input Current a 2-wire, I2C interface. The patented sampling scheme n Directly Digitizes High Impedance Sensors with eliminates dynamic input current errors and the shortcom- Full Accuracy ings of on-chip buffering through automatic cancellation of n 2-Wire I2C Interface with 27 Addresses Plus One differential input current. This allows large external source Global Address for Synchronization impedances and rail-to-rail input signals to be directly n 600nV RMS Noise (0.02LSB Transition Noise) digitized while maintaining exceptional DC accuracy. n GND to VCC Input/Reference Common Mode Range The LTC2497 includes an integrated oscillator. This device n Simultaneous 50Hz/60Hz Rejection can be configured to measure an external signal from com- n 2ppm INL, No Missing Codes binations of 16 analog input channels operating in single- n 1ppm Offset and 15ppm Full-Scale Error ended or differential modes. It automatically rejects line n No Latency: Digital Filter Settles in a Single Cycle, frequencies of 50Hz and 60Hz simultaneously. Even After a New Channel Is Selected n Single Supply, 2.7V to 5.5V Operation (0.8mW) The LTC2497 allows a wide, common mode input range n Internal Oscillator (0V to VCC), independent of the reference voltage. Any n Tiny 5mm × 7mm QFN Package combination of single-ended or differential inputs can be selected and the first conversion, after a new channel is applicaTions selected, is valid. Access to the multiplexer output enables optional external amplifiers to be shared between all n Direct Sensor Digitizer analog inputs and auto calibration continuously removes n Direct Temperature Measurement their associated offset and drift. n Instrumentation L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and No Latency ∆∑ and Easy Drive are trademarks of Linear Technology Corporation. All other n Industrial Process Control trademarks are the property of their respective owners. Typical applicaTionEasy Drive Data Acquisition System+FS Error vs RSOURCE at IN+ and IN– 2.7V TO 5.5V 80 VCC = 5V 60 VREF = 5V V + CH0 MUXOUT/ V 10µF 0.1µF IN = 3.75V CC – CH1 ADCIN 40 VIN = 1.25V fO = GND • • 20 TA = 25°C • REF+ 1.7k CH7 C IN+ IN = 1mF 16-CHANNEL CH8 SDA 0 16-BIT ∆∑ ADC MUX 2-WIRE • WITH EASY DRIVE • SCL I2C INTERFACE –20 • IN– +FS ERROR (ppm) CH15 REF– –40 COM f –60 O MUXOUT/ OSC ADCIN –80 2497 TA01 1 10 100 1k 10k 100k RSOURCE (Ω) 2497 TA01b 2497fb For more information www.linear.com/LTC2497 1 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Converter Characteristics Analog Input and Reference I2C Inputs And Digital Outputs Power Requirements Digital Inputs And Digital Outputs I2C Timing Characteristics Typical Performance Characteristics Pin Functions Functional Block Diagram Applications Information Package Description Revision History Typical Application Related Parts
