LTC2494 16-Bit 8-/16-Channel DS ADC with PGA and Easy Drive Input Current Cancellation FeaturesDescription n Up to 8 Differential or 16 Single-Ended Inputs The LTC®2494 is a 16-channel (8-differential), 16-bit, No n Easy DriveTM Technology Enables Rail-to-Rail Latency DS™ 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 Programmable Gain from 1 to 256 input signals to be directly digitized while maintaining n Integrated High Accuracy Temperature Sensor exceptional DC accuracy. n GND to VCC Input/Reference Common Mode Range The LTC2494 includes programmable gain, a high accu- n Programmable 50Hz, 60Hz or Simultaneous racy temperature sensor and an integrated oscillator. This 50Hz/60Hz Rejection Mode device can be configured to measure an external signal n 2ppm INL, No Missing Codes (from combinations of 16 analog input channels operat- n 1ppm Offset and 15ppm Full-Scale Error ing in single-ended or differential modes) or its internal n 2x Speed Mode/Reduced Power Mode (15Hz Using temperature sensor. The integrated temperature sensor Internal Oscillator and 80µA at 7.5Hz Output) offers 1/2°C resolution and 2°C absolute accuracy. The n No Latency: Digital Filter Settles in a Single Cycle, LTC2494 can be configured to provide a programmable Even After a New Channel Is Selected gain from 1 to 256 in 8 steps. n Single-Supply 2.7V to 5.5V Operation n Internal Oscillator The LTC2494 allows a wide common mode input range n Tiny 5mm × 7mm QFN 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. n Direct Sensor Digitizer L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and n Direct Temperature Measurement No Latency ∆∑ and Easy Drive are trademarks of Linear Technology Corporation. All other n Instrumentation trademarks are the property of their respective owners. n Industrial Process Control typical applicationData Acquisition System with Temperature CompensationAbsolute Temperature Error 5 2.7V TO 5.5V 4 CH0 MUXOUT/ VCC 0.1µF 10µF 3 ADCIN CH1 2 • • • REF+ 1 CH7 IN+ SDI 16-CHANNEL 0 CH8 16-BIT ∆Σ ADC SCK MUX 4-WIRE • WITH EASY-DRIVE SDO SPI INTERFACE –1 • • IN– CS –2 CH15 ABSOLUTE ERROR (°C) REF– COM –3 –4 fO TEMPERATURE MUXOUT/ –5 SENSOR OSC ADCIN –55 –30 –5 20 45 70 95 120 TEMPERATURE (°C) 2494 TA01a 2494 TA01b 2494fe For more information www.linear.com/LTC2494 1