LTC2480 16-Bit ∆Σ ADC with Easy Drive Input Current Cancellation FEATURESDESCRIPTION n Extended Temperature Range of –40°C to 125°C The LTC®2480 combines a 16-bit plus sign No Latency n Easy Drive Technology Enables Rail-to-Rail Inputs ∆Σ™ analog-to-digital converter with patented Easy Drive™ with Zero Differential Input Current technology. The patented sampling scheme eliminates n Directly Digitizes High Impedance Sensors with dynamic input current errors and the shortcomings of on- Full Accuracy chip buffering through automatic cancellation of differential n Programmable Gain from 1 to 256 input current. This al ows large external source impedances n GND to VCC Input/Reference Common Mode Range and input signals, with rail-to-rail input range to be directly n Programmable 50Hz, 60Hz or Simultaneous digitized while maintaining exceptional DC accuracy. 50Hz/60Hz Rejection Mode The LTC2480 includes on-chip programmable gain and n 2ppm (0.25LSB) INL, No Missing Codes an oscillator. The LTC2480 can be configured to provide a n 1ppm Offset and 15ppm Full-Scale Error programmable gain from 1 to 256 in 8 steps, measure an n Selectable 2x Speed Mode (15Hz Using Internal external signal or internal temperature sensor and reject Oscillator) line frequencies. 50Hz, 60Hz or simultaneous 50Hz/60Hz n No Latency: Digital Filter Settles in a Single Cycle line frequency rejection can be selected as well as a 2x n Single Supply 2.7V to 5.5V Operation speed-up mode. n Internal Oscillator n Available in a Tiny (3mm × 3mm) 10-Lead The LTC2480 allows a wide common mode input range DFN Package and 10-Lead MSOP Package (0V to VCC) independent of the reference voltage. The APPLICATIONS reference can be as low as 100mV or can be tied directly to VCC. The LTC2480 includes an on-chip trimmed oscil- lator eliminating the need for external crystals or oscil- n Direct Sensor Digitizer lators. Absolute accuracy and low drift are automatically n Weight Scales maintained through continuous, transparent, offset and n Direct Temperature Measurement full-scale calibration. n Strain Gauge Transducers L, LT, LTC and LTM, Linear Technology and the Linear logo are registered trademarks and n Instrumentation No Latency ∆Σ and Easy Drive are trademarks of Linear Technology Corporation. All other n Industrial Process Control trademarks are the property of their respective owners. Patents pending. n DVMs and Meters TYPICAL APPLICATION+FS Error vs RSOURCE at IN+ and IN– 80 VCC = 5V VCC 60 VREF = 5V V + IN = 3.75V – 40 VIN = 1.25V 1µF 0.1µF fO = GND 20 TA = 25°C 10k SDI IDIFF = 0 V C REF VCC IN = 1µF V + 0 IN SDO SENSE LTC2480 4-WIRE SCK –20 SPI INTERFACE +FS ERROR (ppm) V – IN CS –40 10k GND fO 2480 TA01 0.1µF –60 –80 1 10 100 1k 10k 100k RSOURCE (Ω) 2480 TA04 2480fe For more information www.linear.com/LTC2480 1 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics (Normal Speed) Electrical Characteristics (2X Speed) Converter Characteristics Analog Input and Reference Analog Inputs and Digital Outputs Power Requirements Timing Characteristics Typical Performance Characteristics Pin Functions Functional Block Diagram Test Circuits Timing Diagrams Applications Information Package Description Revision History Typical Application Related Parts
