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Configurable output ranges reduce the need for multiple product variants to support various range options. This circuit uses the AD5422 16-bit, serial input, unipolar/bipolar voltage and current output DAC to provide voltage output ranges of 0 V to 5 V, 0 V to 10 V, −5 V to +5 V, or −10 V to +10 V with a 10% overrange capability; a current output, accessed from a separate pin, can provide 4 mA to 20 mA, 0 mA to 20 mA, or 0 mA to 24 mA ranges. The current and voltage output pins can be connected together by adding a buffer amplifier or switch to prevent a current leakage path through an internal resistor when the device is in current output mode.
This Application Note describes how to apply the ADE7912/ADE7913 isolated sigma-delta ADCs to measure analog 4-mA to 20-mA current loops. Current loops implement a robust sensor standard, so many industrial process control applications still employ them for analog signaling. The signaling current flows through all components, with the same current flowing even if the terminations are less than perfect, and all loop components drop voltage due to the current flowing through them. The signaling current is not affected by these voltage drops as long as the supply voltage is greater than the sum of the drops around the loop at the maximum current.
The ADE7912 and ADE7913 isolated 3-channel, Σ-Δ ADCs target polyphase energy metering applications using shunt current sensors. The devices can be used to sense dc signals, however, so this 5-page Application Note presents their dc measurement performance. In energy metering applications, the current channel is used to sense the voltage across shunt current sensors and the voltage channels are used to measure voltages across resistor dividers. From a dc measurement perspective, this separation is not meaningful because every channel can be used to sense dc signals. This application note describes the performance when dc signals are applied at the inputs of the three Σ-Δ ADCs.
Blood analyzers, in-vitro diagnostic systems, and other chemical analysis applications require fluid transfer from one vessel to another. These systems must efficiently aspirate samples from cuvettes or reagents from bottles. Lab-based systems that process large numbers of samples must process them as quickly as possible. To minimize the impact of probe motion on processing time, the probes used for aspiration must move at high speed. Moving the probe efficiently requires accurate knowledge of the location of the probe in relation to the surface of the fluid being drawn. This Application Note demonstrates how a capacitance-to-digital converter (CDC) can be used to determine the probe location with a high level of confidence.
The evaluation board for the AD9129 14-bit, 5.6-GSPS RF digital-to-analog converter uses power supply filters to guarantee optimal performance. This 3-page Application Note explores the effects of removing most of the filter components. All ferrite beads on the board were removed, as well as the majority of the capacitors on the power supplies. Phase noise, noise spectral density (NSD), spurious-free dynamic range (SFDR), intermodulation distortion (IMD), and adjacent channel leakage ratio (ACLR) performance were all measured to demonstrate the effect of removing the filter components. The measurement results showed that the ferrite beads improved close-in phase noise at 20 Hz offset by approximately 5 dB, as well as single-tone IMD by up to 5 dB. Most of the capacitors proved to be redundant, however. The decoupling capacitors improved the ACLR for 6 MHz carriers by 5 dB; and the capacitor arrays improved the ACLR for 6 MHz carriers by approximately 6 dB and the NSD by approximately 1 dB. Removing all of the other the capacitors did not affect the performance.
This 18-page Application Note answers a series of frequently asked questions about digital potentiometer (digiPOT) products. It includes general questions as well as specific questions, including product-specific questions. In addition, it provides digiPOT configuration information.
This 7-page Application Note describes using the AD5755 and other similar industrial DACs in applications that do not require the dynamic power control (DPC) feature. DPC operates by sensing the load on the current output pin and supplying only the power that is required. To achieve this, the DAC controls a dc-to-dc converter to step up a 5-V supply to between 7.4 V and 29.5 V. DPC is particularly useful in systems with wide load ranges, including a short-circuit to ground, where all power generated by the supply is dissipated on chip. In non-DPC systems, this results in higher IC and system temperatures. Low-power applications may not require dynamic power control. In these cases, the dc-to-dc converter can be excluded from the design, reducing the number of external components. This is useful for space-constrained applications that require four channels. Instead of using the dc-to-dc converter, an external PMOS can limit on-chip power dissipation, or the DAC can be powered directly, with all power dissipated on chip.
High-performance data acquisition signal chains used for spectroscopy, magnetic resonance imaging (MRI), and gas chromatography—and vibration, oil/gas, and seismic systems demand a state-of-the-art, high dynamic range (DR) while addressing difficult thermal design, space, and cost challenges. One way to achieve a higher dynamic range is to oversample the converter to accurately monitor and measure both small and large input signals from the sensors. Other ways include using programmable-gain amplifiers or operating multiple ADCs in parallel, using digital postprocessing to average the result. These methods may be cumbersome or impractical to implement in some systems, mainly due to power, space, and cost constraints. This 4-page Application Note focuses on the oversampling of high-throughput, 5‑MSPS, 18-bit/16-bit precision successive approximation register (SAR) converters by implementing a straightforward averaging of ADC output samples to increase the dynamic range.
The ADE7854A/ADE7858A/ADE7868A/ADE7878A are enhanced versions of the ADE7854/ADE7858/ADE7868/ ADE7878 energy measurement ICs. This Application Note describes the differences between these products and is recommended for use alongside the data sheet.
This 12-bit, 1-MSPS data-acquisition system uses only two active devices. The system processes charge input signals from piezoelectric sensors using a single 3.3-V supply and has a total error of less than 0.25% FSR after calibration over a ±10°C temperature range, making it ideal for a wide variety of laboratory and industrial measurements. The circuit’s small footprint makes this combination an industry-leading solution for data-acquisition systems where accuracy, speed, cost, and size play a critical role.
This complete single-supply,16-bit buffered voltage output DAC maintains ±1 LSB integral and differential nonlinearity by utilizing a CMOS DAC followed by an innovative amplifier that has no crossover distortion. The circuit eliminates the crossover nonlinearity associated with most rail-to-rail op amps that can be as high as 4 LSBs to 5 LSBs in a 16-bit system. This industry leading solution is ideal for industrial process control and instrumentation applications that require a compact, single-supply, low-cost, highly linear 16-bit buffered voltage source. Total power dissipation for the three active devices is less than 25 mW typical when operating on a single 6-V supply.
This completely isolated 12-bit, 300-kSPS RTD
temperature measuring system uses only three active devices to process the
output of a Pt100 RTD. An innovative circuit provides lead-wire
compensation using a standard 3-wire connection. The circuit operates on a
This completely isolated 12-bit, 300-kSPS data-acquisition system uses only three active devices to process 4-mA to 20-mA input signals using a single 3.3-V supply. The total error after room temperature calibration is ±0.06% FSR over a ±10°C temperature range, making it ideal for a wide variety of industrial measurements. The small footprint makes it an industry-leading solution for 4-mA to 20-mA data acquisition systems where accuracy, speed, cost, and size play a critical role. Both data and power are isolated, making the circuit robust to high voltages and ground-loop interference often encountered in harsh industrial environments.
This completely isolated 12-bit, 300-kSPS data
acquisition system uses only three active devices to process ±10-V input
signals using a single
This circuit combines the AD5755-1 four-channel voltage and current output DAC with dynamic power control and the AD5700-1 HART modem, to impement a completely isolated multiplexed HART analog output solution. Power can be provided either from the transformer isolated power circuit provided on the board or from external power supplies connected to terminal blocks. This circuit is suitable for use in programmable logic controllers (PLCs) and distributed control system (DCS) modules that require multiple HART-compatible 4 mA to 20 mA current outputs, along with unipolar or bipolar voltage outputs. External transient protection circuitry is also included, which is important for applications located in harsh industrial environments.
This complete, fully isolated, analog output channel is suitable for programmable logic controllers (PLCs) and distributed control system (DCS) modules that require standard 4 mA to 20 mA HART®-compatible current outputs and unipolar or bipolar output voltage ranges. It provides a flexible building block for channel-to-channel isolated PLC/DCS output modules or any other industrial application that requires a fully isolated analog output. The circuit also includes external protection on the analog output terminals. The AD5422 16-bit digital-to-analog converter (DAC) is software configurable and provides all the necessary current and voltage outputs. The AD5700-1 HART-compliant modem, used in conjunction with the AD5422, forms a complete HART-compatible 4 mA to 20 mA solution. The AD5700-1 includes a precision internal oscillator that provides additional space savings, especially in channel-to-channel isolated applications.
24-bit, 250-kSPS Sigma-Delta ADC with 20-μs settling and rail-to-rail buffers
The AD7175-2 low-noise multiplexed Σ-Δ analog-to-digital converter accepts two fully differential or four pseudo-differential low-bandwidth inputs. The fast settling design has a maximum 50-kSPS channel scan rate and 5-SPS to 250-kSPS output data rates. The integrated analog- and digital signal conditioning blocks allow individual configuration for each input channel. True rail-to-rail buffers on the analog- and external reference inputs provide easy to drive high-impedance inputs. The precision 2.5-V low-drift (2 ppm/°C) reference and reference buffer add functionality and reduce external component count. The digital filter allows simultaneous 50/60 Hz rejection at 27.27 SPS output data rate. The ADC automatically cycles through each selected channel. Further digital processing functions include offset and gain calibration. Operating with +5-V and ±2.5-V supplies, the AD7175-2 dissipates 105 mW with buffers enabled, internal clock, and internal reference; 42 mW with buffers disabled, external clock, and external reference; 125 µW in standby mode, and 25 µW in power-down mode. Available in a 24-lead TSSOP package, it is specified from –40°C to +105°C and priced at $11.85 in 1000s.
Dual 12-bit, 1-GSPS Pipelined ADC has JESD204B outputs
AD9234 dual 12-bit, 1-GSPS analog-to-digital
converter includes an on-chip buffer and sample-and-hold circuit, making it
small, low power, and easy to use. Designed for sampling analog signals up
to 2 GHz, it is optimized for wide bandwidth, high sampling rate, excellent
linearity, and low power in a small package. An on-chip voltage reference
eases design considerations. The ADC cores use a multistage, differential
pipelined architecture with integrated output error correction logic. Each
ADC output is connected to an optional decimate-by-2 block. Several
functions, including a fast threshold detector and a signal monitor, simply
the automatic-gain control (AGC) function. The JESD204B-based high-speed
serialized outputs are configurable in a variety of one-, two-, or four-lane
alternatives via a 3-wire SPI-compatible interface. Operating on 1.25-V,
1.8-V, 2.5-V, and 3.3-V supplies, the AD9234 dissipates 3 W in normal mode,
1.25 W in standby mode, and 750 mW in power-down mode.
Available in a
Polyphase Multifunction Energy Metering ICs
The ADE7854A/ADE7858A/ADE7868A/ADE7878A high accuracy, 3-phase electrical energy measurement ICs include 2nd-order Σ-Δ ADCs, a digital integrator, reference circuitry, and all signal processing required to perform total (fundamental and harmonic) active, reactive (ADE7858A, ADE7868A, and ADE7878A), and apparent energy measurement and rms calculations. The ADE7878A can also perform fundamental-only active and reactive energy measurement and rms calculations. A fixed-function DSP executes the signal processing from a program stored in the on-chip ROM. The devices can measure active, reactive, and apparent energy in various 3-phase configurations, such as wye or delta services, with both three and four wires. They provide rms offset correction, phase calibration, and gain calibration for each phase. Operating on a single 3.3-V supply, the ADE78xxA draw 20 mA in normal mode, 4.5 mA in PSM1 mode, 0.2 mA in PSM2 mode, and 1.7 µA in PSM3 mode. Available in 40-lead LFCSP packages, they are specified from –40°C to +85°C and priced from $4.73 in 1000s.
Quad, 16-bit, 2.8-GSPS, TxDAC+® Digital-to-Analog Converter
AD9144 quad, 16-bit, 2.8-GSPS digital-to-analog
converter (DAC) enables multicarrier generation up to the Nyquist frequency.
The low-distortion design specifies 82-dBc spurious-free dynamic range
(SFDR), 90‑dBc intermodulation distortion (IMD), and –162-dBm/Hz noise
spectral density (NSD). The DAC outputs interface seamlessly with the
ADRF672x analog quadrature modulators (AQMs). An optional 3- or 4-wire
serial port interface (SPI) allows programming/readback of many internal
parameters. The full-scale output current can be programmed over a typical
range of 13.9 mA to 27.0 mA. The AD9144 operates on 1.2-V, 1.3-V, 1.8-V and
3.3-V supplies. Available in an 88-lead LFCSP package, it is specified from
Dual 16-bit, 310-MSPS pipelined ADC provides LVDS outputs
The AD9652 dual, 16-bit analog-to-digital converter samples at up to 310 MSPS. Designed to support high-speed signal-processing applications that require high dynamic range over a wide input frequency range, its –157.6-dBFS noise floor and 85 dBFS spurious-free dynamic range (SFDR) allow low-level signals to be resolved in the presence of large signals. The dual ADC cores feature a multistage, pipelined architecture with integrated output error correction logic. The high-performance on-chip voltage reference and buffer minimize external circuitry. The ADC can support input clock frequencies of up to 1.24 GHz, with a 1×, 2×, 4×, or 8× clock divider generating the ADC sample clock. A duty cycle stabilizer compensates for variations in the ADC clock duty cycle. The two16-bit ADC outputs are interleaved onto a single LVDS output port along with a double-data-rate (DDR) clock. Programming for setup and control are accomplished via a 3-wire SPI-compatible serial interface. Operating on 1.8-V and 3.3-V supplies, the AD9652 dissipates 2.2 W in normal mode, 80 mW in standby mode, and 1 mW in power-down mode. Available in a 144-ball CSP-BGA package, it is specified from –40°C to +85°C and priced at $231.25 in 1000s.
Analog Front-End for radar receive path includes ADC, 4-channel LNA/PGA/AAF
The AD8285 analog front-end for radar receive paths includes four channels of low-noise amplifier (LNA), programmable-gain amplifier (PGA), and antialiasing filter (AAF), plus a direct-to-ADC channel, a 5-channel multiplexer, and a 12-bit ADC. Each channel has a 16-dB to 34-dB gain range in 6-dB increments; and the ADC converts at up to 72 MSPS. The combined input referred noise voltage of the entire channel is 3.5 nV/√Hz at maximum gain. Designed for low cost, low power, compact size, flexibility, and ease of use, the device is optimized for dynamic performance and low power in applications where a small package size is critical. Operating on 1.8-V and 3.3-V supplies, the AD8285 dissipates 185 mW in normal mode and 5 mW in power-down mode. Available in a 72-lead power LFCSP package, it is specified from –40°C to +105°C and priced at $8.33 in 1000s.
Maithil Pachchigar, Key Considerations for Multiplexed Data-Acquisition Systems, Planet Analog, 2014-08-11
Jonathan Harris, Interfacing to ADCs: Power Supplies, Part 2, Planet Analog, 2014-08-04
Trevor Caldwell, David Alldred, and Zhao Li, Reconfigurable ADC With Up to 100 MHz Bandwidth Using Flash Reference Shuffling, IEEE Transactions on Circuits and Systems, 2014-08-01
Rob Reeder, SDR: How to get a major head start in ecosystem design, EDN, 2014-07-16
Jonathan Harris, Interfacing to ADCs: Power Supplies, Part 1, Planet Analog, 2014-07-07
Maithil Pachchigar, Demystifying High-Performance Multiplexed Data-Acquisition Systems, Analog Dialogue, 2014-07-02
Ian Beavers, Understanding Spurious-Free Dynamic Range In Wideband GSPS ADCs, Semiconductor Network, 2014-07-01
Del Jones, JESD204B Subclasses (part 2): Subclass 1 vs. 2, System Considerations, EDN, 2014-06-25
Del Jones, JESD204B Subclasses (part 1): Intro and Deterministic Latency, EDN, 2014-06-18
Duncan Bosworth, Demand for digital: Challenges and solutions for high-speed ADCs and RADAR systems, EDN, 2014-06-11
David Buchanan, Overranged Converter Recovers Quickly, Analog Dialogue, 2014-06-04
David Buchanan, Overranged Converter Recovers Quickly, Planet Analog, 2014-06-04
Jonathan Harris, ADC Power Supplies: Inputs, Planet Analog, 2014-06-02
Vicky Wong, Zero-crossover-distortion amplifiers improve linearity of DAC Systems, Power Systems Design, 2014-06-01
Rob Reeder, GSPS Converter Wideband Front-End Design, DigiKey, 2014-05-28
Ian Beavers, Understanding Spurious-Free Dynamic Range In Wideband GSPS ADCs, Electronic Design, 2014-05-12
Jonathan Harris, ADC Noise: The Clock Input and Phase Noise, Part 3 – Test Setup, Planet Analog, 2014-04-18
Jim Scarlett, Capacitance-to-Digital Converter Facilitates Level Sensing in Diagnostic Systems, Analog Dialogue, 2014-04-02
Jarrett Liner, Understanding and designing wideband output networks for high speed D/A converters, EDN, 2014-03-19
Ian Beavers and Jeff Ugalde, Selecting the Right Converter: JESD204B vs. LVDS, Xilinx EE Trend, 2014-03-20
Jakub Szymczak, Shane O’Meara, Johnny S. Gealon, and Christopher Nelson De La Rama, Precision Resolver-to-Digital Converter Measures Angular Position and Velocity, Analog Dialogue, 2014-03-03
David Buchanan, Programmable ADC Input Range Provides System Benefits, Analog Dialogue, 2014-03-03
Jonathan Harris, ADC Noise: The Clock Input & Phase Noise (Jitter), Part 2, Planet Analog, 2014-02-27
Ian Beavers, Demystifying Deterministic Latency Within JESD204B Converters, Electronic Design, 2014-02-25
Jonathan Harris, ADC Noise: The Clock Input & Phase Noise (Jitter), Part 1, Planet Analog, 2014-02-18
Gabriele Manganaro, A 12 mW Low Power Continuous-Time Bandpass ΔΣ Modulator With 58 dB SNDR and 24 MHz Bandwidth at 200 MHz IF, JSSC, 2014-02-01
Rob Reeder, Designing for Wideband RF, EDN, 2014-01-28
Rob Reeder, Design Wideband Front Ends for GSPS Converters, Electronic Design, 2014-01-24
Jonathan Harris, ADC Noise: How the Clock Input Can Help, Planet Analog, 2014-01-24
Ian Beavers, Prototyping Systems: JESD204B Converters And FPGAs, Electronic Design, 2014-01-23
Ian Beavers and Jeff Ugalde, Selecting the Right Converter: JESD204B vs. LVDS, Xcell Journal, 2014-01-17
Jonathan Harris, ADC Noise: More on the Analog Inputs, Planet Analog, 2014-01-14
Jonathan Harris, How Do You Analyze ADC Noise? Part 2, Planet Analog, 2013-12-27
Jonathan Harris, How Do You Analyze ADC Noise? Part 1, Planet Analog, 2013-12-26
Maithil Pachchigar, Let's Compare SAR & Δ-Σ Converters for a Mux'd DAS, Part 5, Planet Analog, 2013-12-17
Maithil Pachchigar, Let's Compare SAR & Δ-Σ Converters for a Mux'd DAS, Part 4, Planet Analog, 2013-12-13
Maithil Pachchigar, Let's Compare SAR & Δ-Σ Converters for a Mux'd DAS, Part 3, Planet Analog, 2013-12-12
Jonathan Harris, ADC Power Supply Noise: PSRR & PSMR, Planet Analog, 2013-12-12
Jonathan Harris and Ian Beavers, Why There's No Need to Fear JESD204B, EE Times, 2013-12-11
Maithil Pachchigar, Let's Compare SAR & Δ-Σ Converters for a Mux'd DAS, Part 2 , Planet Analog, 2013-12-11
Maithil Pachchigar, Let's Compare SAR & Δ-Σ Converters for a Mux'd DAS, Part 1 , Planet Analog, 2013-12-10
Maithil Pachchigar and Richard Liggiero, Get ADC data beyond the datasheet, EDN, 2013-12-10
Jonathan Harris, Further into the alphabet with interleaved ADCs, EDN, 2013-12-02
Steven Xie, Successive-Approximation ADCs: Ensuring a Valid First Conversion, Analog Dialogue, 2013-12-02
Maithil Pachchigar, Increase Dynamic Range With SAR ADCs Using Oversampling, Part 2, Planet Analog, 2013-11-22
Maithil Pachchigar, Increase Dynamic Range With SAR ADCs Using Oversampling, Part 1, Planet Analog, 2013-11-21
Jonathan Harris, ADC Noise: A Second Look, Part 2, Planet Analog, 2013-11-15
Jonathan Harris, ADC Noise: A Second Look, Part 1, Planet Analog, 2013-11-14
David Buchanan, Overrange Flag Indicates Data Validity, Analog Dialogue, 2013-11-01
Jonathan Harris, ADC Noise – Where Does It Come From?, Planet Analog, 2013-10-21
Maithil Pachchigar, Data acquisition system enhances images for digital X-Ray and MRI, New Electronics, 2013-10-08
Jonathan Harris, Interleaving Spurs: The Mathematics of Timing Mismatch, Planet Analog, 2013-10-07
Ian Beavers, Pair The Right JESD204B Converter With Your FPGA, Electronic Design, 2013-10-03
Maithil Pachchigar, High-Performance Data-Acquisition System Enhances Images for Digital X-Ray and MRI, Analog Dialogue, 2013-10-01
Jonathan Harris, Interleaving Spurs: More Math Details for Gain Mismatch, Planet Analog, 2013-09-25
Jonathan Harris, Interleaving Spurs: Let’s Look at the Math, Planet Analog, 2013-09-17
Jonathan Harris, Understanding JESD204B Link Parameters, Planet Analog, 2013-09-10
Jonathan Harris, Interleaving Spurs: Bandwidth Mismatches, Planet Analog, 2013-08-29
Yi Zhang and Assaf Toledano, High-Speed DACs Fuel Multiband Transmitters, Microwaves & RF, 2013-08-22
Jonathan Harris, Interleaving Spurs: Timing Mismatches, Planet Analog, 2013-08-21
Alan Walsh, The Mystery of SAR ADC Power Specifications, Planet Analog, 2013-08-14
Rob Reeder, Noise considerations in high-speed converter signal chains, DSP-FPGA, 2013-08-07
David Buchanan, Soft Clipping vs. Hard Clipping, Analog Dialogue, 2013-08-04
High-performance GSPS Data Converters Improve RADAR & EW Architectures - In recent years, ADCs sampling at GSPS rates have been pushing the data conversion stage closer and closer to the antenna, but when analog bandwidths reach 1 to 2 GHz, the ac performance of ADCs may be limited by the linearity and noise spectral density. This webinar discusses the advantages of new GSPS converters and the impact on radar and electronic warfare systems.
Digital Potentiometers - Where and How to Use - Digital Potentiometers (digiPOTs) provide a convenient way to adjust the ac or dc voltage or current output of sensors, power supplies, or other devices that require some type of calibration. This webcast describes the advantages of using digital potentiometers in various applications and shows the main parameters to be considered when designing a circuit using a digital potentiometer.
Designing Wideband Front-ends for GSPS Converters - As high-speed A/D converter technology improves, so does the need to resolve very high intermediate frequencies (IF) accurately at high-speeds. This poses two challenges: the converter design itself, and the front-end design that couples the signal content to the converter. This webcast will define wideband passive networks and highlight important specifications for choosing a transformer or balun.
Solving the Elusive Baseband to Antenna Problem using RFDAC Technology - This webinar will explore RF transmitter architectures, concentrating on the direct-to-RF architecture enabled by RFDAC technology. Aspects of the direct-to-RF transmitter system design will be explored including gain, signal bandwidth, digital signal processing requirements, frequency planning, thermal noise, clock synthesis + phase noise, harmonics, sampling images, pre-distortion techniques, and deterministic latency.
Fundamentals of Data Conversion in Receivers - This webinar examines a contemporary receive signal chain and takes a close look at selecting suitable data converters, their key specifications, and the tradeoffs that must be made.
Fundamentals of Energy Metering - This webinar will explore system architectures for 3‑phase electricity meters, focusing on various current sensors and considerations for the analog front end, power supply and data isolation, metrology computations and system performance. Current transformers (CTs), di/dt (Rogowski coils), and shunt resistors will be discussed.
How to Lower Power Consumption in Data Acquisition Systems -- This webcast will present solutions to lower the power consumption in data-acquisition systems. Among the topics to be discussed are the limitations and tradeoffs of using lower power components, such as ADC drivers and regulators. If you are currently in the design phase of a lower power data-acquisition system, this is a webcast you should attend.
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