LTC2401/LTC2402 1-/2-Channel 24-Bit µPower No Latency ∆ΣTMADCs in MSOP-10 UFEATURESDESCRIPTIO ■ 24-Bit ADCs in Tiny MSOP-10 Packages The LTC®2401/LTC2402 are 1- and 2-channel 2.7V to 5.5V ■ 4ppm INL, No Missing Codes micropower 24-bit analog-to-digital converters with an ■ 4ppm Full-Scale Error integrated oscillator, 4ppm INL and 0.6ppm RMS noise. ■ 0.5ppm Offset These ultrasmall devices use delta-sigma technology and ■ 0.6ppm Noise a new digital filter architecture that settles in a single cycle. ■ Single Conversion Settling Time for This eliminates the latency found in conventional ∆Σ Multiplexed Applications converters and simplifies multiplexed applications. ■ 1- or 2-Channel Inputs Through a single pin, the LTC2401/LTC2402 can be ■ Automatic Channel Selection (Ping-Pong) (LTC2402) configured for better than 110dB rejection at 50Hz or ■ Zero Scale and Full Scale Set for Reference 60Hz ±2%, or can be driven by an external oscillator for and Ground Sensing a user defined rejection frequency in the range 1Hz to ■ Internal Oscillator—No External Components Required 120Hz. The internal oscillator requires no external fre- ■ 110dB Min, 50Hz/60Hz Notch Filter quency setting components. ■ Reference Input Voltage: 0.1V to VCC ■ Live Zero—Extended Input Range Accommodates These converters accept an external reference voltage 12.5% Overrange and Underrange from 0.1V to VCC. With an extended input conversion ■ Single Supply 2.7V to 5.5V Operation range of –12.5% VREF to 112.5% VREF (VREF = FSSET – ■ Low Supply Current (200 ZS µA) and Auto Shutdown SET), the LTC2401/LTC2402 smoothly resolve the off- set and overrange problems of preceding sensors or U signal conditioning circuits. APPLICATIO S ■ Weight Scales The LTC2401/LTC2402 communicate through a 2- or ■ Direct Temperature Measurement 3-wire digital interface that is compatible with SPI and ■ Gas Analyzers MICROWIRETM protocols. ■ Strain Gauge Transducers , LTC and LT are registered trademarks of Linear Technology Corporation. No Latency ∆Σ is a trademark of Linear Technology Corporation. ■ Instrumentation MICROWIRE is a trademark of National Semiconductor Corporation. ■ Data Acquisition ■ Industrial Process Control UTYPICAL APPLICATIOPseudo Differential Bridge Digitizer 2.7V TO 5.5V 2.7V TO 5.5V 1µF VCC= INTERNAL OSC/50Hz REJECTION 1 1 10 VCC V = EXTERNAL CLOCK SOURCE CC FO = INTERNAL OSC/60Hz REJECTION LTC2402 LTC2402 2 FSSET 9 REFERENCE VOLTAGE 2 9 SCK FSSET SCK ZSSET + 0.1V TO VCC 4 CH0 8 3-WIRE SDO ANALOG INPUT RANGE 3 8 3-WIRE CH1 SDO SPI INTERFACE ZS SPI INTERFACE SET – 0.12VREF TO 3 7 FS CH1 CS SET + 0.12VREF 4 7 (V CH0 CS REF = FSSET – ZSSET) 5 10 5 6 ZSSET FO 0V TO FS INTERNAL OSCILLATOR SET – 100mV ZSSET GND GND 60Hz REJECTION 24012 TA01 6 24012TA02 1