LTC2442

` 1ppm Linearity with No Missing Codes
` Integrated Amplifi er for Direct Sensor Digitization
` 2 Differential or 4 Single-Ended Input Channels
` Up to 8kHz Output Rate
` Up to 4kHz Multiplexing Rate
` Selectable Speed/Resolution 2V_RMS Noise at 1.76kHz Output Rate 220nV_RMS Noise at 13.8Hz Output Rate with Simultaneous 50Hz/60Hz Rejection
` Guaranteed Modulator Stability and Lock-Up Immunity for any Input and Reference Conditions
` <5V Offset (4.5V < V_CC < 5.5V, 40°C to 85°C)
` Differential Input and Differential Reference with GND to V<sub>CC</sub> Common Mode Range
` No Latency Mode, Each Conversion is Accurate Even After a New Channel is Selected
` Internal Oscillator-No External Components
` 36-Lead SSOP Package

The LTC^®2442 is an ultra high precision, variable speed, 24-bit ^TM ADC with integrated amplifi er. The amplifi er can be confi gured as a buffer for easy input drive of high impedance sensors. 1 part-per-million (ppm) linearity is achievable when the amplifi er is confi gured in unity gain. External resistors can be used to set a gain for increased resolution of low level input signals. The positive and negative amplifi er supply pins of LTC2442 may be tied directly to V_CC (4.5V to 5.5V) and GND or biased above V_CC and below GND for rail-to-rail input signals.

The proprietary architecture of LTC2442 ensures stable DC accuracy through continuous transparent calibration. Ten speed/resolution combinations from 6.9Hz/220nV_RMS to  3.5kHz/25V_RMS can be selected with no latency or shift in DC accuracy. Additionally, a 2X speed mode can beselected enabling output rates up to 7kHz (8kHz with an  external oscillator) with one cycle latency.

Any combination of single-ended (up to 4 inputs) or differential (up to 2 inputs) can be selected with a common mode input range from ground to V_CC. While operating in the 1X speed mode the fi rst conversion following a new speed/resolution or channel selection is valid.