LTC2412 2-Channel Differential Input 24-Bit No Latency ∆Σ ADC FEATURESDESCRIPTION n 2-Channel Differential Input with Automatic Chan- The LTC®2412 is a 2-channel differential input micropower nel Selection (Ping-Pong) 24-bit No Latency ∆Σ™ analog-to-digital converter with an n Low Supply Current: 200µA, 4µA in Autosleep integrated oscillator. It provides 2ppm INL and 0.16ppm n Differential Input and Differential Reference with RMS noise over the entire supply range. The two differ- GND to VCC Common Mode Range ential channels are converted alternately with channel ID n 2ppm INL, No Missing Codes included in the conversion results. It uses delta-sigma n 2.5ppm Full-Scale Error and 0.1ppm Offset technology and provides single conversion settling of the n 0.16ppm Noise, 22.5 Effective Number of Bits digital filter. Through a single pin, the LTC2412 can be n No Latency: Digital Filter Settles in a Single Cycle and configured for better than 110dB input differential mode Each Channel Conversion is Accurate rejection at 50Hz or 60Hz ±2%, or it can be driven by an n Internal Oscillator—No External Components Re- external oscillator for a user defined rejection frequency. quired The internal oscillator requires no external frequency set- n 110dB Min, 50Hz or 60Hz Notch Filter ting components. n Narrow SSOP-16 Package The converter accepts any external differential reference n Single Supply 2.7V to 5.5V Operation voltage from 0.1V to VCC for flexible ratiometric and re- mote sensing measurement configurations. The full-scale APPLICATIONS differential input range is from –0.5VREF to 0.5VREF. The n reference common mode voltage, VREFCM, and the input Direct Sensor Digitizer n common mode voltage, VINCM, may be independently set Weight Scales n anywhere within the GND to VCC. The DC common mode Direct Temperature Measurement n input rejection is better than 140dB. Gas Analyzers n Strain-Gage Transducers The LTC2412 communicates through a flexible 3-wire digi- n Instrumentation tal interface which is compatible with SPI and MICROWIRE n Data Acquisition protocols. n Industrial Process Control L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and No Latency ∆Σ is a trademark of Linear Technology Corporation. All other trademarks are the n 6-Digit DVMs property of their respective owners. TYPICAL APPLICATIONTotal Unadjusted Error vs Input 2.7V TO 5.5V 1.5 1µF VCC= INTERNAL OSC/50Hz REJECTION 1 14 V = EXTERNAL CLOCK SOURCE CC FO 1.0 2 = INTERNAL OSC/60Hz REJECTION REF+ 4 ) CH0+ 0.5 REF LTC2412 5 13 0 CH0– SCK THERMOCOUPLE 3 12 T REF– 3-WIRE A = 90°C SDO V SPI INTERFACE CC = 5V TUE (ppm OF V –0.5 REF+ = 5V T 6 A = 25°C CH1+ 11 CS REF– = GND TA = –45°C 7 –1.0 VREF = 5V CH1– VINCM = 2.5V 8, 9, 10, 15, 16 F GND O = GND 2412 TA01 –1.5–2.5 –2 –1.5 –1 –0.5 0 0.5 1 1.5 2 2.5 VIN (V) 2412 TA02 2412fa For more information www.linear.com/LTC2412 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Electrical Characteristics Pin Configuration Converter Characteristics Analog Input and Reference Digital Inputs and Digital Outputs Power Requirements Timing Characteristics Typical Performance Characteristics Pin Functions Functional Block Diagram Test Circuit Applications Information Package Description Revision History Typical Application Related Parts