Chemical Analysis & Analytical Instruments

The ADPD4100/ADPD4101 operate as a complete multimodal sensor front end, stimulating up to eight light emitting diodes (LEDs) and measuring the return signal on up to eight separate current inputs. Twelve time slots are available, enabling 12 separate measurements per sampling period.

The data output and functional configuration utilize an I²C interface on the ADPD4101 or a serial port interface (SPI) on the ADPD4100. The control circuitry includes flexible LED signaling and synchronous detection. The devices use a 1.8 V analog core and 1.8 V/3.3 V compatible digital input/output (I/O).

The analog front end (AFE) rejects signal offsets and corruption from asynchronous modulated interference, typically from ambient light, eliminating the need for optical filters or externally controlled dc cancellation circuitry. Multiple operating modes are provided, enabling the ADPD4100/ADPD4101 to be a sensor hub for synchronous measurements of photodiodes, biopotential electrodes, resistance, capacitance, and temperature sensors. The multiple operation modes accommodate various sensor measurements, including, but not limited to, photoplethysmography (PPG), electrocardiography (ECG), electrodermal activity (EDA), impedance, capacitance, temperature, gas detection, smoke detection, and aerosol detection for various healthcare, industrial, and consumer applications.

The ADPD4100/ADPD4101 are available in a 3.11 mm × 2.14 mm, 0.4 mm pitch, 33-ball WLCSP and 35-ball WLCSP

Applications

• Wearable health and fitness monitors: heart rate monitors (HRMs), heart rate variability (HRV), stress, blood pressure estimation, SpO2, hydration, body composition
• Industrial monitoring: CO, CO2, smoke, and aerosol detection
• Home patient monitoring

The AD4630-24/AD4632-24 are two-channel, simultaneous sampling, Easy Drive^™, 2 MSPS or 500 kSPS successive approximation register (SAR) analog-to-digital converters (ADCs). With a guaranteed maximum ±0.9 ppm INL and no missing codes at 24 bits, the AD4630-24/AD4632-24 achieve unparalleled precision from −40°C to +125°C. Figure 1 in the data sheet shows the functional architecture of the AD4630-24/AD4632-24.

A low drift, internal precision reference buffer eases voltage reference sharing with other system circuitry. The AD4630-24/ AD4632-24 offer a typical dynamic range of 106 dB when using a 5 V reference. The low noise floor enables signal chains requiring less gain and lower power. A block averaging filter with programmable decimation ratio can increase dynamic range up to 153 dB. The wide differential input and common-mode ranges allow inputs to use the full voltage reference (±V_REF) range without saturating, simplifying signal conditioning requirements and system calibration. The improved settling of the Easy Drive analog inputs broadens the selection of analog front-end components compatible with the AD4630-24/AD4632-24. Both single-ended and differential signals are supported.

The versatile Flexi-SPI serial peripheral interface (SPI) eases host processor and ADC integration. A wide data clocking window, multiple SDO lanes, and optional dual data rate (DDR) data clocking can reduce the serial clock to 10 MHz while operating at a sample rate of 2 MSPS or 500 kSPS. Echo clock mode and ADC host clock mode relax the timing requirements and simplify the use of digital isolators.

The 64-ball chip scale package ball grid array (CSP_BGA) of the AD4630-24/AD4632-24 integrates all critical power supply and reference bypass capacitors, reducing the footprint and system component count, and lessening sensitivity to board layout.

APPLICATIONS

• Automatic test equipment
• Digital control loops
• Medical instrumentation
• Seismology
• Semiconductor manufacturing
• Scientific instrumentation

The AD3552R is a low drift, ultra-fast, 16-bit accuracy, current output digital-to-analog converter (DAC) that can be configured in multiple voltage span ranges. The AD3552R operates with a fixed 2.5 V reference.

Each DAC incorporates three drift compensating feedback resistors for the required external transimpedance amplifier (TIA) that scales the output voltage. Offset and gain scaling registers allow for generation of multiple output span ranges, such as 0 V to 2.5 V, 0 V to 5 V, 0 V to 10 V, −5 V to +5 V, and −10 V to +10 V, and custom intermediate ranges with full 16-bit resolution.

The DAC can operate in fast mode for maximum speed or precision mode for maximum accuracy.

The serial peripheral interface (SPI) can be configured in quad SPI mode, dual synchronous SPI mode, dual SPI mode, and single SPI (classic SPI) mode with single date rate (SDR) or double data rate (DDR), with logical levels from 1.2 V to 1.8 V.

The AD3552R is specified over the extended industrial temperature range (–40°C to +105°C).

APPLICATIONS

• Instrumentation
• Hardware in the loop
• Process control equipment
• Medical devices
• Automatic test equipment
• Data acquisition system
• Programmable voltage sources
• Optical communications

The ADAQ23875 is a precision, high speed, μModule^® data acquisition solution that reduces the development cycle of a precision measurement systems by transferring the design burden of component selection, optimization, and layout from the designer to the device.

Using system-in-package (SIP) technology, the ADAQ23875 reduces end system component count by combining multiple common signal processing and conditioning blocks in a single device, solving many design challenges. These blocks include a low noise, fully differential analog-to-digital converter (ADC) driver (FDA), a stable reference buffer, and a high speed, 16-bit, 15 MSPS successive approximation register (SAR) ADC.

Using Analog Devices, Inc., iPassives^® technology, the ADAQ23875 also incorporates crucial passive components with superior matching and drift characteristics to minimize temperature dependent error sources and to offer optimized performance (see Figure 1). The fast settling of the ADC driver stage, with fully differential or single-ended to differential input and no latency of the SAR ADC, provides a unique solution for high channel count multiplexed signal chain architectures and control loop applications.

The small footprint, 9 mm × 9 mm CSP_BGA package enables smaller form factor instruments without sacrificing performance. Single, 5 V supply operation is possible while achieving optimum performance from the device. The ADAQ23875 features a serial low voltage differential signaling (LVDS) digital interface with one-lane or two-lane output modes, allowing the user to optimize the interface data rate for each application. The specified operation of the μModule is from −40°C to +85°C.

APPLICATIONS

• ATE
• Data acquisition
• Hardware in the Loop (HiL)
• Power analyzers
• Nondestructive test (acoustic emissions)
• Mass spectrometry
• Travelling wave fault location
• Medical imaging and instruments
• Ultrasonic flow meters

The ADIN1100 is a low power, single port, 10BASE-T1L transceiver designed for industrial Ethernet applications and is compliant with the IEEE^® 802.3cg-2019^™ Ethernet standard for long reach 10 Mbps single pair Ethernet (SPE). The ADIN1100 integrates an Ethernet PHY core with all the associated analog circuitry, input and output clock buffering, the management interface control register and subsystem registers, as well as the MAC interface and control logic to manage the reset, clock control, and pin configuration.

The ADIN1100 supports cable reach of up to 1700 meters with autonegotiation enabled and has ultra low power consumption of 39 mW.

The PHY core supports the 1.0 V p-p operating mode and the 2.4 V p-p operating mode defined in the IEEE 802.3cg standard and can operate from a single power supply rail of 1.8 V or 3.3 V, with the lower voltage option supporting the 1.0 V p-p transmit voltage level.

The ADIN1100 has an integrated voltage supply monitoring circuit and power-on reset (POR) circuitry to improve system level robustness.

The MDIO interface is a 2-wire serial interface for communication between a host processor or MAC and the ADIN1100, thereby allowing access to control and status information in the PHY core management registers. This interface is compatible with both the IEEE 802.3 Standard Clause 22 and Clause 45 management frame structures.

APPLICATIONS

• Process Control
• Factory Automation
• Building Automation
• Field instruments and switches

The MAX328/MA329 are monolithic CMOS analog multiplexers. The MAX328 is a single-ended, 1-of-8 device, and the MAX329 is a differential, 2-of-8 device.

Designed to provide the lowest possible on- and off-leakages, these multiplexers switch signals from high source impedance, providing the mux operates into a high-input-impedance op amp or A/D converter. The MAX328/MAX329 are pin-for-pin replacements for the popular DG508/DG509 in these applications.

Adding an external 40kΩ resistor to each input makes the MAX328/MAX329 an excellent fault-tolerant multiplexer. Low leakage (less than 1pA at +25°C) and 2.5kΩ on-resistance allow the circuit to sustain 110V AC faults indefinitely while maintaining an error of less than 40nV for normal signals (i.e., 1pA times 40kΩ).

The MAX328/MAX329 work equally well with a single supply of 10V to 30V or dual supplies of ±5V to ±18V. They also perform well with unbalanced combinations of supply voltage, such as +12V and -5V or +5V and -15V. Low power dissipation (1.9mW with ±15V supplies) allows use in portable applications.

The MAX44242 provides a combination of high voltage, low noise, low input bias current in a dual channel and features rail-to-rail at the output.

This dual amplifier operates over a wide supply voltage range from a single 2.7V to 20V supply or split ±1.35V to ±10V supplies and consumes only 1.2mA quiescent supply current per channel.

The MAX44242 is a unity-gain stable amplifier with a gain-bandwidth product of 10MHz. The device outputs drive up to 200pF load capacitor without any external isolation resistor compensation.

The MAX44242 is available in 8-pin SOT23 and µMAX^® packages and is rated for operation over the -40°C to +125°C automotive temperature range.

Design Solution: The Incredible Shrinking Encoder ›

Applications

• Chemical Sensor Interface
• Industrial: Process and Control
• Medical Pulse Oximetry
• Photodiode Sensor Interface
• Precision Instrumentation

The LTC6373 is a precision instrumentation amplifier with fully differential outputs which includes a closely-matched internal resistor network to achieve excellent CMRR, offset voltage, gain error, gain drift, and gain nonlinearity. The user can easily program the gain to one of seven available settings through a 3-bit parallel interface (A2 to A0). The 8th state puts the part in shutdown which reduces the current consumption to 220 μA. Unlike a conventional voltage feedback amplifier, the LTC6373 maintains nearly the same bandwidth across all its gain settings.

The LTC6373 features fully differential outputs to drive high performance, differential-input ADCs. The output common mode voltage is independently adjustable via the V_OCM pin. The combination of high impedance inputs, DC precision, low noise, low distortion, and high-speed differential ADC drive makes the LTC6373 an ideal candidate for optimizing data acquisition systems.

The LTC6373 is available in a 12-lead 4 mm × 4 mm DFN (LFCSP) package and is fully specified over the −40°C to +105°C temperature range.

Applications

• Data Acquisition Systems
• Biomedical Instrumentation
• Test and Measurement Equipment
• Differential ADC Drivers
• Single-Ended-to-Differential Conversion
• Multiplexed Applications

The LTC6240/6241/LTC6242 are single, dual and quad low noise, low offset, rail-to-rail output, unity gain stable CMOS op amps that feature 1pA of input bias current. Input bias current is guaranteed to be 1pA max on the single LTC6240. The 0.1Hz to 10Hz noise of only 550nV_P-P, along with an offset of just 125μV are significant improvements over traditional CMOS op amps. Additionally, noise is guaranteed to be less than 10nV/√Hz at 1kHz. An 18MHz gain bandwidth, and 10V/μs slew rate, along with the wide supply range and low input capacitance, make them perfect for use as fast signal processing amplifiers.

These op amps have an output stage that swings within 30mV of either supply rail to maximize the signal dynamic range in low supply applications. The input common mode range extends to the negative supply. They are fully specified on 3V and 5V, and an HV version guarantees operation on supplies up to ±5V.

The LTC6240 is available in the 8-pin SO and the 5-pin SOT-23 packages. The LTC6241 is available in the 8-pin SO, and for compact designs it is packaged in a tiny dual fine pitch leadless (DFN) package. The LTC6242 is available in the 16-pin SSOP as well as the 5mm × 3mm DFN package.

Applications

• Photo Diode Amplifiers
• Charge Coupled Amplifiers
• Low Noise Signal Processing
• Medical Instrumentation
• High Impedance Transducer Amplifier

The LTC6655 is a complete family of precision bandgap voltage references, offering exceptional noise and drift performance. This low noise and drift is ideally suited for the high resolution measurements required by instrumentation and test equipment. In addition, the LTC6655 is fully specified over the temperature range of –40°C to 125°C, ensuring its suitability for demanding automotive and industrial applications. Advanced curvature compensation allows this bandgap reference to achieve a drift of less than 2ppm/°C with a predictable temperature characteristic and an output voltage accurate to ±0.025%, reducing or eliminating the need for calibration.

The LTC6655LN Low Noise comes with a noise reduction pin that enables reduction of wideband noise with the addition of a single capacitor.

The LTC6655 can be powered from as little as 500mV above the output voltage to as much as 13.2V. Superior load regulation with source and sink capability, coupled with exceptional line rejection, ensures consistent performance over a wide range of operating conditions. A shutdown mode is provided for low power applications.

The LTC6655 references are offered in an 8-lead MSOP package and an 8-lead LS8 package. The LS8 is a 5mm × 5mm surface mount hermetic package that provides outstanding stability.

APPLICATIONS

• Instrumentation and Test Equipment
• High Resolution Data Acquisition Systems
• Weigh Scales
• Precision Battery Monitors
• Precision Regulators
• Medical Equipment

The LTC6078/LTC6079 are dual/quad, low offset, low noise operational amplifiers with low power consumption and rail-to-rail input/output swing.

Input offset voltage is trimmed to less than 25μV and the CMOS inputs draw less than 50pA of bias current. The low offset drift, excellent CMRR, and high voltage gain make it a good choice for precision signal conditioning.

Each amplifier draws only 54μA current on a 3V supply. The micropower, rail-to-rail operation of the LTC6078/LTC6079 is well suited for portable instruments and single supply applications.

The LTC6078/LTC6079 are specified on power supply voltages of 3V and 5V from -40 to 125°C. The dual amplifier LTC6078 is available in 8-lead MSOP and 10-lead DFN packages. The quad amplifier LTC6079 is available in 16-lead SSOP and DFN packages.

Applications

• Photodiode Amplifier
• High Impedance Sensor Amplifier
• Microvolt Accuracy Threshold Detection
• Instrumentation Amplifiers
• Battery Powered Applications

The LT3045 is a high performance low dropout linear regulator featuring LTC’s ultralow noise and ultrahigh PSRR architecture for powering noise sensitive applications. Designed as a precision current reference followed by a high performance voltage buffer, the LT3045 can be easily paralleled to further reduce noise, increase output current and spread heat on the PCB.

The device supplies 500mA at a typical 260mV dropout voltage. Operating quiescent current is nominally 2.2mA and drops to <<1µA in shutdown. The LT3045’s wide output voltage range (0V to 15V) while maintaining unity-gain operation provides virtually constant output noise, PSRR, bandwidth and load regulation, independent of the programmed output voltage. Additionally, the regulator features programmable current limit, fast start-up capability and programmable power good to indicate output voltage regulation.

The LT3045 is stable with a minimum 10µF ceramic output capacitor. Built-in protection includes reverse-battery protection, reverse-current protection, internal current limit with foldback and thermal limit with hysteresis. The LT3045 is available in thermally enhanced 12-Lead MSOP and 10-Lead 3mm × 3mm DFN packages.

The LT3045-EP supports defense and aerospace applications (AQEC)

APPLICATIONS

• RF Power Supplies: PLLs, VCOs, Mixers, LNAs, PAs
• Very Low Noise Instrumentation
• High Speed/High Precision Data Converters
• Medical Applications: Imaging, Diagnostics
• Precision Power Supplies
• Post-Regulator for Switching Supplies

The LT8609S is a compact, high efficiency, high speed synchronous monolithic step-down switching regulator that consumes only 1.7µA of non-switching quiescent current. The LT8609S can deliver 2A of continuous current with peak loads of 3A (<1sec) to support applications such as GSM transceivers which require high transient loads. Top and bottom power switches are included with all necessary circuitry to minimize the need for external components. Low ripple Burst Mode operation enables high efficiency down to very low output currents while keeping the output ripple below 10mV_P-P. A SYNC pin allows synchronization to an external clock, or spread spectrum modulation of switching frequencies for low EMI operation. Internal compensation with peak current mode topology allows the use of small inductors and results in fast transient response and good loop stability. The EN/UV pin has an accurate 1V threshold and can be used to program V_IN undervoltage lockout or to shut down the LT8609S reducing the input supply current to 1µA. A capacitor on the TR/SS pin programs the output voltage ramp rate during start-up while the PG flag signals when V_OUT is within ±8.5% of the programmed output voltage as well as fault conditions. The LT8609S is available in a small 16-lead 3mm × 3mm LQFN package.

APPLICATIONS

• General Purpose Step Down
• Low EMI Step Down

The LTM8049 is a Dual SEPIC/Inverting μModule^® (power module) DC/DC Converter. Each of the two outputs can be easily configured as a SEPIC or Inverting converter by simply grounding the appropriate output rail. The LTM8049 includes power devices, inductors, control circuitry and passive components. All that is needed to complete the design are input and output caps, and small resistors to set the output voltages and switching frequency. Other components may be used to control the soft-start and undervoltage lockout.

The LTM8049 is packaged in a thermally enhanced, compact (15mm × 9mm) over-molded Ball Grid Array (BGA) package suitable for automated assembly by standard surface mount equipment. The LTM8049 is RoHS compliant.

Applications

• Battery Powered Regulator
• Local Negative Voltage Regulator
• Low Noise Amplifier Power

The ADuCM355 is an on-chip system that controls and measures electrochemical sensors and biosensors. The ADuCM355 is an ultralow power, mixed-signal microcontroller based on the Arm^® Cortex^™-M3 processor. The device features current, voltage, and impedance measurement capability.

The ADuCM355 features a 16-bit, 400 kSPS, multichannel successive approximation register (SAR) analog-to-digital converter (ADC) with input buffers, built-in antialias filter (AAF), and programmable gain amplifier (PGA). The current inputs include three transimpedance amplifiers (TIA) with programmable gain and load resistors for measuring different sensor types. The analog front end (AFE) also contains two low power amplifiers designed specifically for potentiostat capability to maintain a constant bias voltage to an external electrochemical sensor. The noninverting inputs of these two amplifiers are controlled by on-chip, dual output digital-to-analog converters (DACs). The analog outputs include a high speed DAC and output amplifier designed to generate an ac signal.

The ADC operates at conversion rates up to 400 kSPS with an input range of −0.9 V to +0.9 V. An input mux before the ADC allows the user to select an input channel for measurement. These input channels include three external current inputs, multiple external voltage inputs, and internal channels. The internal channels allow diagnostic measurements of the internal supply voltages, die temperature, and reference voltages.

Two of the three voltage DACs are dual output, 12-bit string DACs. One output per DAC controls the noninverting input of a potentiostat amplifier, and the other controls the noninverting input of the TIA.

The third DAC (sometimes referred to as the high speed DAC) is designed for the high power TIA for impedance measurements. The output frequency range of this DAC is up to 200 kHz.

A precision 1.82 V and 2.5 V on-chip reference source is available. The internal ADC and voltage DAC circuits use this on-chip reference source to ensure low drift performance for all peripherals.

The ADuCM355 integrates a 26 MHz Arm Cortex-M3 processor, which is a 32-bit reduced instruction set computer (RISC) machine. The Arm Cortex-M3 processor also has a flexible multichannel direct memory access controller (DMA) supporting two independent serial peripheral interface (SPI) ports, universal asynchronous receiver/transmitter (UART), and I²C communication peripherals. The ADuCM355 has 128 kB of nonvolatile flash/EE memory and 64 kB of single random access memory (SRAM) integrated on-chip.

The digital processor subsystem is clocked from a 26 MHz on-chip oscillator. The oscillator is the source of the main digital die system clock. Optionally, a 26 MHz phase-locked loop (PLL) can be used as the digital system clock. This clock can be internally subdivided so that the processor operates at a lower frequency and saves power. A low power, internal 32 kHz oscillator is available and can clock the timers. The ADuCM355 includes three general-purpose timers, a wake-up timer (which can be used as a general-purpose timer), and a system watchdog timer.

The analog subsystem has a separate 16 MHz oscillator used to clock the ADC, DACs, and other digital logic on the analog die. The analog die also contains a separate 32 kHz, low power oscillator to clock a watchdog timer on the analog die. Both the 32 kHz oscillator and this watchdog are independent from the digital die oscillators and system watchdog timer.

A range of communication peripherals can be configured as required in a specific application. These peripherals include UART, I²C, two SPI ports, and general-purpose input/output (GPIO) ports. The GPIOs, combined with the general-purpose timers, can be combined to generate a pulse-width modulation (PWM) type output.

Nonintrusive emulation and program download are supported via the serial wire debug port (SW-DP) interface.

The ADuCM355 operates from a 2.8 V to 3.6 V supply and is specified over a temperature range of −40°C to +85°C. The chip is packaged in a 72-lead, 6 mm × 5 mm land grid array (LGA) package.

Note that, throughout this data sheet, multifunction pins, such as P0.0/SPI0_CLK, are referred to either by the entire pin name or by a single function of the pin, for example, P0.0, when only that function is relevant.

Applications

• Gas detection
• Food quality
• Environmental sensing (air, water, and soil)
• Blood glucose meters
• Life sciences and biosensing analysis
• Bioimpedance measurements
• General Amperometry, voltammetry, and impedance spectroscopy functions

The ADA4530-1 is a femtoampere (10⁻¹⁵ A) level input bias current operational amplifier suitable for use as an electrometer that also includes an integrated guard buffer. It has an operating voltage range of 4.5 V to 16 V, enabling it to operate in conventional 5 V and 10 V single supply systems as well as ±2.5 V and ±5 V dual supply systems.

It provides ultralow input bias currents that are production tested at 25°C and at 125°C to ensure the device meets its performance goals in user systems. The integrated guard buffer isolates the input pins from leakage in the printed circuit board (PCB), minimizes board component count, and enables easy system design. The ADA4530-1 is available in an industry-standard surface-mount 8-lead SOIC package with a unique pinout optimized to prevent signals from coupling between the sensitive input pins, the power supplies, and the output pin while enabling easy routing of the guard ring traces.

The ADA4530-1 also offers low offset voltage, low offset drift, and low voltage and current noise needed for the types of applications that require such low leakages.

To maximize the dynamic range of the system, the ADA4530-1 has a rail-to-rail output stage that can typically drive to within 30 mV of the supply rails under a 10 kΩ load.

The ADA4530-1 operates over the −40°C to +125°C industrial temperature range and is available in an 8-lead SOIC package.

Applications

• Laboratory and analytical instrumentation: spectrophotometers, chromatographs, mass spectrometers, and potentiostatic and amperostatic coulometry
• Instrumentation: picoammeters and coulombmeters
• Transimpedance amplifier (TIA) for photodiodes, ion chambers, and working electrode measurements
• High impedance buffering for chemical sensors and capacitive sensors

The ADA4350 is an analog front end for photodetectors or other sensors whose output produces a current proportional to the sensed parameter or voltage input applications where the system requires the user to select between very precise gain levels to maximize the dynamic range.

The ADA4350 integrates a FET input amplifier, a switching network, and an ADC driver with all functions controllable via a serial peripheral interface (SPI) or parallel control logic into a single IC. The FET input amplifier has very low voltage noise and current noise making it an excellent choice to work with a wide range of photodetectors, sensors, or precision data acquisition systems.

Its switching network allows the user individual selection of up to six different, externally configurable feedback networks; by using external components for the feedback network, the user can more easily match the system to their desired photodetector or sensor capacitance. This feature also allows the use of low thermal drift resistors, if required.

The design of the switches minimizes error sources so that they add virtually no error in the signal path. The output driver can be used in either single-ended or a differential mode and is ideal for driving the input of an ADC.

The ADA4350 can operate from a single +3.3 V supply or a dual ±5 V supply, offering user flexibility when choosing the polarity of the detector. It is available in a Pb-free, 28-lead TSSOP package and is specified to operate over the −40°C to +85°C temperature range. Multifunction pin names may be referenced by their relevant function only.

Applications

• Current to voltage (I to V) conversions
• Photodiode preamplifiers
• Chemical analyzers
• Mass spectrometry
• Molecular spectroscopy
• Laser/LED receivers
• Data acquisition systems

The AD7175-2 is a low noise, fast settling, multiplexed, 2-/4- channel (fully/pseudo differential) Σ-Δ analog-to-digital converter (ADC) for low bandwidth inputs. It has a maximum channel scan rate of 50 kSPS (20 µs) for fully settled data. The output data rates range from 5 SPS to 250 kSPS.

The AD7175-2 integrates key analog and digital signal conditioning blocks to allow users to configure an individual setup for each analog input channel in use. Each feature can be user selected on a per channel basis. Integrated true rail-to-rail buffers on the analog inputs and external reference inputs provide easy to drive high impedance inputs. The precision 2.5 V low drift (2 ppm/°C) band gap internal reference (with output reference buffer) adds embedded functionality to reduce external component count.

The digital filter allows simultaneous 50 Hz/60 Hz rejection at 27.27 SPS output data rate. The user can switch between different filter options according to the demands of each channel in the application. The ADC automatically switches through each selected channel. Further digital processing functions include offset and gain calibration registers, configurable on a per channel basis.

The device operates with a 5 V AVDD1, or ±2.5 V AVDD1/AVSS, and 2 V to 5 V AVDD2 and IOVDD supplies. The specified operating temperature range is −40°C to +105°C. The AD7175-2 is in a 24-lead TSSOP package.

Applications

• Process control: PLC/DCS modules
• Temperature and pressure measurement
• Medical and scientific multichannel instrumentation
• Chromatography

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 Σ-Δ 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 AV_DD/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 more robust 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 AD5791¹ is a single 20-bit, unbuffered voltage-output DAC that operates from a bipolar supply of up to 33 V. The AD5791 accepts a positive reference input in the range 5 V to V_DD – 2.5 V and a negative reference input in the range V_SS + 2.5 V to 0 V. The AD5791 offers a relative accuracy specification of ±1 LSB max, and operation is guaranteed monotonic with a ±1 LSB differential nonlinearity (DNL) maximum specification.

The device uses a versatile 3-wire serial interface that operates at clock rates up to 35 MHz and that is compatible with standard serial peripheral interface (SPI), QSPI™, MICROWIRE™, and DSP interface standards. The device incorporates a power-on reset circuit that ensures the DAC output powers up to 0 V and in a known output impedance state and remains in this state until a valid write to the device takes place. The device provides an output clamp feature that places the output in a defined load state.

Product Highlights

1. 1 ppm Accuracy.
2. Wide Power Supply Range up to ±16.5 V.
3. Operating Temperature Range: −40°C to +125°C.
4. Low 7.5 nV/√Hz Noise Spectral Density.
5. Low 0.05 ppm/°C Temperature Drift.

The ADAQ7980/ADAQ7988 are 16-bit analog-to-digital converter (ADC) μModule^® data acquisition systems that integrate four common signal processing and conditioning blocks into a system in package (SiP) design that supports a variety of applications. These devices contain the most critical passive components, eliminating many of the design challenges associated with traditional signal chains that use successive approximation register (SAR) ADCs. These passive components are crucial to achieving the specified device performance.

The ADAQ7980/ADAQ7988 contain a high accuracy, low power, 16-bit SAR ADC, a low power, high bandwidth, high input impedance ADC driver, a low power, stable reference buffer, and an efficient power management block. Housed within a tiny, 5 mm × 4 mm LGA package, these products simplify the design process for data acquisition systems. The level of system integration of the ADAQ7980/ADAQ7988 solves many design challenges, while the devices still provide the flexibility of a configurable ADC driver feedback loop to allow gain and/or common-mode adjustments. A set of four device supplies provides optimal system performance; however, single-supply operation is possible with minimal impact on device operating specifications.

The ADAQ7980/ADAQ7988 integrate within a compact, integrated circuit (IC)-like form factor key components commonly used in data acquisition signal chain designs. The μModule family transfers the design burden of component selection, optimization, and layout from designer to device, shortening overall design time, system troubleshooting, and ultimately improving time to market.

The serial peripheral interface (SPI)-compatible serial interface features the ability to daisy-chain multiple devices on a single, 3-wire bus and provides an optional busy indicator. The user interface is compatible with 1.8 V, 2.5 V, 3 V, or 5 V logic.

Specified operation of these devices is from −55°C to +125°C.

APPLICATIONS

• Automated test equipment (ATE)
• Battery powered instrumentation
• Communications
• Data acquisition
• Process control
• Medical instruments