LTC2404/LTC2408 4-/8-Channel 24-Bit µPower No Latency ∆ΣTM ADCs UFEATURESDESCRIPTIO ■ Pin Compatible 4-/8-Channel 24-Bit ADCs The LTC®2404/LTC2408 are 4-/8-channel 2.7V to 5.5V ■ Single Conversion Digital Filter Settling Time micropower 24-bit A/D converters with an integrated Simplifies Multiplexing oscillator, 4ppm INL and 0.3ppm RMS noise. They use ■ 4ppm INL, No Missing Codes delta-sigma technology and provide single cycle digital ■ 4ppm Full-Scale Error filter settling time (no latency delay) for multiplexed ■ 0.5ppm Offset applications. The first conversion after the channel is ■ 0.3ppm Noise changed is always valid. Through a single pin the LTC2404/ ■ Internal Oscillator—No External Components LTC2408 can be configured for better than 110dB rejec- Required tion at 50Hz or 60Hz ±2%, or can be driven by an external ■ 110dB Min, 50Hz/60Hz Notch Filter oscillator for a user defined rejection frequency in the ■ Reference Input Voltage: 0.1V to V range 1Hz to 120Hz. The internal oscillator requires no CC ■ Live Zero—Extended Input Range Accommodates external frequency setting components. 12.5% Overrange and Underrange The converters accept any external reference voltage from ■ Single Supply 2.7V to 5.5V Operation 0.1V to VCC. With their extended input conversion range of ■ Low Supply Current (200µA) and Auto Shutdown –12.5% VREF to 112.5% VREF the LTC2404/LTC2408 U smoothly resolve the offset and overrange problems of APPLICATIO S preceding sensors or signal conditioning circuits. ■ Weight Scales The LTC2404/LTC2408 communicate through a flexible ■ Direct Temperature Measurement 4-wire digital interface which 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 ■ 6-Digit DVMs UTYPICAL APPLICATIOTotal Unadjusted Error vs Output Code 0.1V TO VCC 2.7V TO 5.5V 10 VDD = 5V 8 7 4 3 2, 8 V 1µF REF = 5V T MUXOUT ADCIN V A = 25°C REF VCC 6 FO = LOW 9 CH0 SERIAL DATA LINK MICROWIRE AND 4 10 CH1 23 CSADC SPI COMPATABLE 2 11 CH2 20 CSMUX ANALOG 0 12 CH3 19 SCK INPUTS 4-/8-CHANNEL 24-BIT 13 CH4* 25 –2 –0.12V ∆Σ ADC CLK MPU REF TO MUX 1.12V 21 –4 REF 14 CH5* DIN LINEARITY ERROR (ppm) 15 CH6* 24 SDO –6 17 CH7* LTC2404/LTC2408 VCC –8 = INTERNAL OSC/50Hz REJECTION 26 = EXTERNAL CLOCK SOURCE –10 GND FO = INTERNAL OSC/60Hz REJECTION 0 8,338,608 16,777,215 2404/08 TA01 1, 5, 6, 16, 18, 22, 27, 28 OUTPUT CODE (DECIMAL) *THESE PINS ARE NO CONNECTS ON THE LTC2404 2404/08 TA02 1