Analog Devices Inc./Maxim Integrated

The LTC2433-1 is a differential input micropower 16-bit No Latency ∆ΣTManalog-to-digital converter with an integrated oscillator. It provides 0.12LSB INL and 1.45µV RMS noise independent of VREF. It uses delta-sigma technology and provides single conversion settling of the digital filter. Through a single pin, the LTC2433-1 can be configured for better than 87dB input differential mode rejection at 50Hz and 60Hz ±2%, or it can be driven by an external oscillator for a user defined rejection frequency. The internal oscillator requires no external frequency setting components.The converter accepts any external differential reference voltage from 0.1V to VCCfor flexible ratiometric and remote sensing measurement configurations. The fullscale differential input range is from – 0.5 • VREFto 0.5 • VREF. The reference common mode voltage, VREFCM, and the input common mode voltage, VINCM, may be independently set anywhere between GND and VCC. The DC common mode input rejection is better than 140dB.The LTC2433-1 communicates through a flexible 3-wire digital interface which is compatible with SPI and MICROWIRE protocols.ApplicationsDirect Sensor DigitizerWeight ScalesDirect Temperature MeasurementGas AnalyzersStrain-Gage TransducersInstrumentationData AcquisitionIndustrial Process Control

The LTC2436-1 is a 2-channel differential input micropower 16-bit No Latency ∆Σ™analog-to-digital converter with an integrated oscillator. It provides 0.5LSB INL and 800nV RMS noise independent of VREF. The two differential channels convert alternately with a channel identification included in the conversion result. It uses delta-sigma technology and provides single conversion settling of the digital filter. Through a single pin, the LTC2436-1 can be configured for better than 87dB input differential mode rejection at 50Hz and 60Hz ±2%, or it can be driven by an external oscillator for a user defined rejection frequency. The internal oscillator requires no external frequency setting components.The converter accepts any external differential reference voltage from 0.1V to VCCfor flexible ratiometric and remote sensing measurement configurations. The full-scale differential input range is from –0.5 • VREFto 0.5 • VREF. The reference common mode voltage, VREFCM, and the input common mode voltage, VINCM, may be independently set anywhere between GND and VCC. The DC common mode input rejection is better than 140dB.The LTC2436-1 communicates through a flexible 3-wire digital interface which is compatible with SPI and MICROWIRE™protocols.ApplicationsDirect Sensor DigitizerWeight ScalesDirect Temperature MeasurementGas AnalyzersStrain-Gage TransducersInstrumentationData AcquisitionIndustrial Process Control

The LTC2439-1 is a 16-channel (8-differential) micropower 16-bit ∆Σ analog-to-digital converter. It operates from 2.7V to 5.5V and includes an integrated oscillator, 0.12LSB INL and 1µV RMS noise. It uses delta-sigma technology and provides single cycle settling time for multiplexed applications. Through a single pin, the LTC2439-1 can be configured for better than 87dB differential mode rejection at 50Hz and 60Hz ±2%, or it can be driven by an external oscillator for a user-defined rejection frequency. The internal oscillator requires no external frequency setting components.The LTC2439-1 accepts any external differential reference voltage from 0.1V to VCCfor flexible ratiometric and remote sensing measurement applications. It can be configured to take 8 differential channels or 16 single-ended channels. The full-scale bipolar input range is from –0.5VREFto 0.5VREF. The reference common mode voltage, VREFCM, and the input common mode voltage, VINCM, may be independently set between GND and VCC. The DC common mode input rejection is better than 140dB.The LTC2439-1 communicates through a flexible 4-wire digital interface that is compatible with SPI and MICROWIRE protocols.ApplicationsDirect Sensor DigitizerWeight ScalesDirect Temperature MeasurementGas AnalyzersStrain Gauge TransducersInstrumentationData AcquisitionIndustrial Process Control

The LTC2440 is a high speed 24-bit No Latency ∆∑™ADC with 5ppm INL and 5µV offset. It uses proprietary Delta Sigma architecture enabling variable speed and resolution with no latency. Ten speed/resolution combinations (6.9Hz/ 200nVRMSto 3.5kHz/25µVRMS) are programmed through a simple serial interface. Alternatively, by tying a single pin HIGH or LOW, a fast (880Hz/2µVRMS) or ultralow noise (6.9Hz, 200nVRMS, 50/60Hz rejection) speed/resolution combination can be easily selected. The accuracy (offset, full-scale, linearity, drift) and power dissipation are independent of the speed selected. Since there is no latency, a speed/resolution change may be made between conversions with no degradation in performance.Following each conversion cycle, the LTC2440 automatically enters a low power sleep state. Power dissipation may be reduced by increasing the duration of this sleep state. For example, running at the 3.5kHz conversion speed but reading data at a 100Hz rate draws 240µA average current (1.1mW) while reading data at a 7Hz output rate draws only 25µA (125µW).The LTC2440 communicates through a flexible 3-wire or 4-wire digital interface that is compatible with the LTC2410 and is available in a narrow 16-lead SSOP package.ApplicationsHigh Speed MultiplexingWeight ScalesAuto Ranging 6-Digit DVMsDirect Temperature MeasurementHigh Speed Data Acquisition

The LTC2442 is an ultra high precision, variable speed, 24-bit ΔΣ™ADC with integrated amplifier. The amplifier can be configured as a buffer for easy input drive of high impedance sensors. 1 part-per-million (ppm) linearity is achievable when the amplifier is configured in unity gain. External resistors can be used to set a gain for increased resolution of low level input signals. The positive and negative amplifier supply pins may be tied directly to VCC(4.5V to 5.5V) and GND or biased above VCCand below GND for rail-to-rail input signals.The proprietary ΔΣ architecture ensures stable DC accuracy through continuous transparent calibration. Ten speed/resolution combinations from 6.9Hz/220nVRMSto 3.5kHz/25µVRMScan be selected with no latency or shift in DC accuracy. Additionally, a 2X speed mode can be selected 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 VCC. While operating in the 1X speed mode the first conversion following a new speed/resolution or channel selection is valid.ApplicationsAuto Ranging 6-Digit DVMsHigh Speed MultiplexingWeight ScalesDirect Temperature MeasurementHigh Speed Data Acquisition

The LTC2444/LTC2445/LTC2448/LTC2449 are 8-/16- channel (4-/8-differential) high speed 24-bit No Latency ∆∑ ADCs. They use a proprietary delta-sigma architecture enabling variable speed/resolution. Through a simple 4-wire serial interface, ten speed/resolution combinations 6.9Hz/280nVRMSto 3.5kHz/25µVRMS(4kHz with external oscillator) can be selected with no latency between conversion results or shift in DC accuracy (offset, full-scale, linearity, drift). Additionally, a 2X speed mode can be selected enabling output rates up to 7kHz (8kHz if an external oscillator is used) with one cycle latency.Any combination of single-ended or differential inputs can be selected with a common mode input range from ground to VCC, independent of VREF. While operating in the 1X speed mode the first conversion following a new speed, resolution, or channel selection is valid. Since there is no settling time between conversions, all 8 differential channels can be scanned at a rate of 500Hz. At the conclusion of each conversion, the converter is internally reset eliminating any memory effects between successive conversions and assuring stability of the high order delta-sigma modulator.ApplicationsHigh Speed MultiplexingWeight ScalesAuto Ranging 6-Digit DVMsDirect Temperature MeasurementHigh Speed Data Acquisition

The LTC2446/LTC2447 4-terminal switching enables multiplexed ratiometric measurements. Four sets of selectable differential inputs coupled with four sets of differential reference inputs allow multiple RTDs, bridges and other sensors to be digitized by a single converter. A fifth differential reference input can be selected for any input channel not requiring ratiometric measurements (thermocouples, voltages, current sense, etc.). The flexible input multiplexer allows single-ended or differential inputs coupled with a slaved reference input or a universal reference input.A proprietary delta-sigma architecture results in absolute accuracy (offset, full-scale, linearity) of 15ppm, noise as low as 200nVRMSand speeds as high as 8kHz. Through a simple 4-wire interface, ten speed/resolution combinations can be selected. The first conversion following a speed, resolution, channel change or reference change is valid since there is no settling time between conversions, enabling scan rates of up to 4kHz. Additionally, a 2x mode can be selected for any speed-enabling output rates up to 8kHz with one cycle of latency.Protected by U.S. Patents, including 6140950, 6169506, 6208279, 6411242, 6639526ApplicationsFlowWeight ScalesPressureDirect Temperature MeasurementGas Chromatography