LTC2498 24-Bit 8-/16-Channel ΔS ADC with Easy Drive Input Current Cancellation FeaturesDescription n Up to 8 Differential or 16 Single-Ended Inputs The LTC®2498 is a 16-channel (8-differential) 24-bit No n Easy Drive™ Technology Enables Rail-to-Rail Latency ΔS™ ADC with Easy Drive technology. The pat- Inputs with Zero Differential Input Current ented sampling scheme eliminates dynamic input current n Directly Digitizes High Impedance Sensors with errors and the shortcomings of on-chip buffering through Full Accuracy automatic cancellation of differential input current. This n 600nV RMS Noise allows large external source impedances, and rail-to-rail n Integrated High Accuracy Temperature Sensor input signals to be directly digitized while maintaining n GND to VCC Input/Reference Common Mode Range exceptional DC accuracy. n Programmable 50Hz, 60Hz or Simultaneous The LTC2498 includes a high accuracy temperature sensor 50Hz/60Hz Rejection Mode and an integrated oscillator. This device can be configured n 2ppm INL, No Missing Codes to measure an external signal (from combinations of 16 n 1ppm Offset and 15ppm Full-Scale Error analog input channels operating in single ended or dif- n 2x Speed Mode (15Hz Using Internal Oscillator) ferential modes) or its internal temperature sensor. The n No Latency: Digital Filter Settles in a Single Cycle, integrated temperature sensor offers 1/30th °C resolution Even After a New Channel Is Selected and 2°C absolute accuracy. n Single Supply 2.7V to 5.5V Operation (0.8mW) n Internal Oscillator The LTC2498 allows a wide common mode input range n Tiny QFN 5mm × 7mm Package (0V to VCC), independent of the reference voltage. Any combination of single-ended or differential inputs can be applications selected and the first conversion after a new channel is selected is valid. Access to the multiplexer output enables n Direct Sensor Digitizer optional external amplifiers to be shared between all analog n Direct Temperature Measurement inputs and auto calibration continuously removes their n Instrumentation associated offset and drift. n Industrial Process Control 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 trademarks are the property of their respective owners. typical applicationInternal SensorData Acquisition System with Temperature CompensationAbsolute Temperature Error 5 2.7V TO 5.5V 4 3 CH0 MUXOUT/ VCC 0.1µF 10µF CH1 ADCIN 2 • REF+ • 1 • IN+ SDI CH7 16-CHANNEL 24-BIT ∆Σ ADC SCK 0 CH8 MUX 4-WIRE WITH EASY DRIVE • SDO SPI INTERFACE –1 • IN– • CS CH15 REF– ABSOLUTE ERROR (°C) –2 COM –3 fO TEMPERATURE –4 MUXOUT/ OSC SENSOR ADCIN –5–55 –30 –5 20 45 70 95 120 2498 TA01a TEMPERATURE (°C) 2498 TA01b 2498fg For more information www.linear.com/LTC2498 1 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics (Normal Speed) Electrical Characteristics (2x Speed) Converter Characteristics Analog Input and Reference Digital Inputs and Digital Outputs Power Requirements Digital Inputs and Digital Outputs Typical Performance Characteristics Pin Functions Functional Block Diagram Test Circuits Timing Diagrams Applications Information Package Description Revision History Related Parts