The AD5940 and AD5941 are high precision, low power analog front ends (AFEs) designed for portable applications that require high precision, electrochemical-based measurement techniques, such as amperometric, voltammetric, or impedance measurements. The AD5940/AD5941 is designed for skin impedance and body impedance measurements, and works with the AD8233 AFE in a complete bioelectric or biopotential measurement system. The AD5940/AD5941 is designed for electrochemical toxic gas sensing.The AD5940/AD5941 consist of two high precision excitation loops and one common measurement channel, which enables a wide capability of measurements of the sensor under test. The first excitation loop consists of an ultra low power, dual-output string, digital-to-analog converter (DAC), and a low power, low noise potentiostat. One output of the DAC controls the noninverting input of the potentiostat, and the other output controls the noninverting input of the transimpedance amplifier (TIA). This low power excitation loop is capable of generating signals from dc to 200 Hz.The second excitation loop consists of a 12-bit DAC, referred to as the high speed DAC. This DAC is capable of generating high frequency excitation signals up to 200 kHz.The AD5940/AD5941 measurement channel features a 16-bit, 800 kSPS, multichannel successive approximation register (SAR) analog-to-digital converter (ADC) with input buffers, a built in antialias filter, and a programmable gain amplifier (PGA). An input multiplexer (mux) in front of the ADC allows the user to select an input channel for measurement. These input channels include multiple external current inputs, external voltage inputs, and internal channels. The internal channels allow diagnostic measurements of the internal supply voltages, die temperature, and reference voltages.The current inputs include two TIAs with programmable gain and load resistors for measuring different sensor types. The first TIA, referred to as the low power TIA, measures low bandwidth signals. The second TIA, referred to as the high speed TIA, measures high bandwidth signals up to 200 kHz.An ultra low leakage, programmable switch matrix connects the sensor to the internal analog excitation and measurement blocks. This matrix provides an interface for connecting external transimpedance amplifier resistors (RTIAs) and calibration resistors. The matrix can also be used to multiplex multiple electronic measurement devices to the same wearable electrodes.A precision 1.82 V and 2.5 V on-chip reference source is available. The internal ADC and DAC circuits use this on-chip reference source to ensure low drift performance for the 1.82 V and 2.5 V peripherals.The AD5940/AD5941 measurement blocks can be controlled via direct register writes through the serial peripheral interface (SPI) interface, or, alternatively, by using a preprogrammable sequencer, which provides autonomous control of the AFE chip. 6 kB of static random access memory (SRAM) is partitioned for a deep data first in, first out (FIFO) and command FIFO. Measurement commands are stored in the command FIFO and measurement results are stored in the data FIFO. A number of FIFO related interrupts are available to indicate when the FIFO is full.A number of general-purpose inputs/outputs (GPIOs) are available and controlled using the AFE sequencer. The AFE sequencer allows cycle accurate control of multiple external sensor devices.The AD5940/AD5941 operate from a 2.8 V to 3.6 V supply and are specified over a temperature range of ?40?C to +85?C. The AD5940 is packaged in a 56-lead, 3.6 mm ? 4.2 mm WLCSP. The AD5941 is packaged in a 48-lead LFCSP.APPLICATIONS Electrochemical measurements Electrochemical gas sensors Potentiostat/amperometric/voltammetry/cyclic voltammetry Bioimpedance applications Skin impedance Body impedance Continuous glucose monitoring Battery impedance

The AD7124-4 is a low power, low noise, completely integrated analog front end for high precision measurement applications. The device contains a low noise, 24-bit ?-? analog-to-digital converter (ADC), and can be configured to have 4 differential inputs or 7 single-ended or pseudo differential inputs. The onchip low gain stage ensures that signals of small amplitude can be interfaced directly to the ADC.One of the major advantages of the AD7124-4 is that it gives the user the flexibility to employ one of three integrated power modes. The current consumption, range of output data rates, and rms noise can be tailored with the power mode selected. The device also offers a multitude of filter options, ensuring that the user has the highest degree of flexibility.The AD7124-4 can achieve simultaneous 50 Hz and 60 Hz rejection when operating at an output data rate of 25 SPS (single cycle settling), with rejection in excess of 80 dB achieved at lower output data rates.The AD7124-4 establishes the highest degree of signal chain integration. The device contains a precision, low noise, low drift internal band gap reference, and also accepts an external differential reference, which can be internally buffered. Other key integrated features include programmable low drift excitation current sources, burnout currents, and a bias voltage generator, which sets the common-mode voltage of a channel to AVDD/2. The low-side power switch enables the user to power down bridge sensors between conversions, ensuring the absolute minimal power consumption of the system. The device also allows the user the option of operating with either an internal clock or an external clock.The integrated channel sequencer allows several channels to be enabled simultaneously, and the AD7124-4 sequentially converts on each enabled channel, simplifying communication with the device. As many as 16 channels can be enabled at any time; a channel being defined as an analog input or a diagnostic such as a power supply check or a reference check. This unique feature allows diagnostics to be interleaved with conversions.The AD7124-4 also supports per channel configuration. The device allows eight configurations or setups. Each configuration consists of gain, filter type, output data rate, buffering, and reference source. The user can assign any of these setups on a channel by channel basis.The AD7124-4 also has extensive diagnostic functionality integrated as part of its comprehensive feature set. These diagnostics include a cyclic redundancy check (CRC), signal chain checks, and serial interface checks, which lead to a morerobust solution. These diagnostics reduce the need for external components to implement diagnostics, resulting in reduced board space needs, reduced design cycle times, and cost savings. The failure modes effects and diagnostic analysis (FMEDA) of a typical application has shown a safe failure fraction (SFF) greater than 90% according to IEC 61508.The device operates with a single analog power supply from 2.7 V to 3.6 V or a dual 1.8 V power supply. The digital supply has a range of 1.65 V to 3.6 V. It is specified for a temperature range of ?40?C to +105?C. The AD7124-4 is housed in a 32-lead LFCSP package or a 24-lead TSSOP package.Applications Temperature measurement? Pressure measurement? Industrial process control? Instrumentation Smart transmitters Smart transmitters

The AD7171 is a very low power, 16-bit, analog-to-digitalconverter (ADC). It contains a precision, 16-bit, ?-? ADC andan on-chip oscillator. Consuming only 135 ?A, the AD7171 isparticularly suitable for portable or battery operated productswhere very low power is a requirement. The AD7171 also has apower-down mode in which the device consumes 5 ?A, thusincreasing the battery life of the product.For ease of use, dedicated pins control all of the features of theAD7171. Each time a data read occurs, eight status bits areappended to the 16-bit conversion. These status bits contain apattern sequence that can be used to confirm the validity of theserial transfer.The output data rate of the AD7171 is 125 Hz, whereas the settlingtime is 24 ms. The AD7171 has one differential input and a gainof 1. This is useful in applications where the user needs to use anexternal amplifier to implement system-specific filtering or gainrequirements.The AD7171 operates with a power supply from 2.7 V to 5.25 V.It is available in a 10-lead LFCSP.The AD7170 is a 12-bit version of the AD7171. It has the samefeature set as the AD7171 and is pin-for-pin compatible.Applications Weigh scales Pressure measurement Industrial process control Portable instrumentation

The AD7192 is a low noise, complete analog front end for high precision measurement applications. It contains a low noise, 24-bit sigma-delta (?-?) analog-to-digital converter (ADC). The on-chip low noise gain stage means that signals of small amplitude can be interfaced directly to the ADC.The device can be configured to have two differential inputs or four pseudo differential inputs. The on-chip channel sequencer allows several channels to be enabled, and the AD7192 sequentially converts on each enabled channel. This simplifies communication with the part. The on-chip 4.92 MHz clock can be used as the clock source to the ADC or, alternatively, an external clock or crystal can be used. The output data rate from the part can be varied from 4.7 Hz to 4.8 kHz.The device has two digital filter options. The choice of filter affects the rms noise/noise-free resolution at the programmed output data rate, the settling time, and the 50 Hz/60 Hz rejection. For applications that require all conversions to be settled, the AD7192 includes a zero latency feature.The part operates with a power supply from 3 V to 5.25 V. It consumes a current of 4.35 mA. It is housed in a 24-lead TSSOP package.ApplicationsWeigh scalesStrain gage transducersPressure measurementPressure measurementTemperature measurementChromatographyPLC/DCS analog input modulesData acquisitionMedical and scientific instrumentation

The AD7380/AD7381 are a 16-bit and 14-bit pin-compatible family of dual simultaneous sampling, high speed, low power, successive approximation register (SAR) analog-to-digital converters (ADCs) that operate from a 3.0 V to 3.6 V power supply and feature throughput rates up to 4 MSPS. The analog input type is differential, accepts a wide common-mode input?voltage, and is sampled and converted on the falling edge of CS.An integrated on-chip oversampling block improves dynamic range and reduces noise at lower bandwidths. A buffered internal 2.5 V reference is included. Alternatively, an external?reference up to 3.3 V can be used.The conversion process and data acquisition use standard control?inputs allowing simple interfacing to microprocessors or digital signal processors (DSPs). The device is compatible with 1.8 V, 2.5 V, and 3.3 V interfaces using the separate logic supply.The AD7380/AD7381 are available in a 16-lead lead frame chip scale package (LFCSP) with operation specified from ?40?C to +125?C.Product highlights Dual simultaneous sampling and conversion with two complete ADC functions. Pin-compatible product family. High 4 MSPS throughput rate. Space saving 3 mm ? 3 mm LFCSP. An integrated oversampling block to increase dynamic range, reduce noise, and reduce SCLK speed requirements. Differential analog inputs with wide common-mode range. Small sampling capacitor reduces amplifier drive burden.Applications Motor control position feedback Motor control current sense Sonar Power quality Data acquisition systems Erbium doped fiber amplifier (EDFA) applications I and Q demodulation

DC851A-E: Demo Board for the LTC2295 Dual 14-Bit, 10Msps Low Power 3V ADC.

DC851A-G: Demo Board for the LTC2298 Dual 14-Bit, 65Msps Low Power 3V ADCs.

DC851A-H: Demo Board for the LTC2294 Dual 12-Bit, 80Msps Low Power 3V ADC.

DC852A: Demo Board for the LTC4354 Negative Voltage Diode-OR Controller and Monitor.

Demonstration circuit 856A is a 500mA, 1.25MHz Synchronous Boost Converter featuring the LTC3427EDC. The demo circuit demonstrates a DC/DC boost converter, with a 500mA switch current limit, providing 3.3V at 180mA from a 1.8V to 3.6V input voltage.