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Application notes that were published within the past 12 months.
The integration of overvoltage protection (OVP) into an amplifier front end is a mechanism for addressing the environmental factors related to the normal operation of op amps. In 2014, the release of the ADA4177 family brought the Analog Devices integrated OVP solution to a low noise, precision op amp for the first time. This application note explores the application of the OVP feature as it applies to the ADA4177 and provides guidance on ways that the new OVP can allow users to extend the protected range while preventing overcurrent to the inputs and limiting self-heating.
State-of-the-art motor drives use a 3-phase, insulated gate bipolar transistor (IGBT)-based inverter that is powered by a dc link voltage typically in the region of 400 V dc to 800 V dc. That high voltage rail can be derived directly from a 3-phase rectifier bridge filter combination or from a power factor corrected boost rectifier, which produces the high voltage rail from a 3-phase ac input. This detailed application note addresses some of the basic requirements and considerations involved with designing these bias rails.
For any given output frequency, the ADF4355-2 uses a certain voltage controlled oscillator (VCO) core, band, and bias code. These three settings are selected automatically during the VCO automatic calibration (AUTOCAL) cycle and the settings are read from the ADF4355-2 and stored in a lookup table. This application note shows how to use this lookup table to bypass the AUTOCAL routine which dramatically decreases the total lock time when changing the frequency.
Though ADCs with differential inputs can accept single-ended input signals, optimum ADC performance is achieved when the input signal is differential. This application note addresses the design considerations around ADC drivers—circuits often specifically designed to provide such differential signals—that perform many additional important functions, including amplitude scaling, single-ended to differential conversion, buffering, common-mode offset adjustment, and filtering.
This application note describes the use and design implementation of the EVAL-ADF7242-PMDZ, a 2.4 GHz wireless transceiver peripheral module (Pmod™) evaluation board that uses an ADF7242 transceiver in conjunction with a Johanson 2450AT18A100 chip antenna. The chip antenna makes the ADF7242 evaluation board more compact, more cost effective, and easier to use.
The ADP1055 digital controller for power supply applications with PMBus interface offers a register map and an EEPROM that are programmed with settings for a specific application. This application note focuses on the software procedure to program the ADP1055.
The ADA4530-1 is a single, electrometer grade operational amplifier with a femtoampere (10−15) level input bias current (IB) and an ultralow offset voltage. This application note highlights several different methods for measuring the ADA4530-1 femtoampere level input bias current feature in the SOIC package using the ADA4530-1R-EBZ-TIA or the ADA4530-1R-EBZ-BUF evaluation board.
The current loop is a common signaling technique for sending and receiving sensor data over long distances. This application note highlights the AD8479 serving as a front end for a current loop transmitter that enables the transmitter to operate in applications with very high CMV, such as motor controls and high voltage current sensing.
Current sense amplifiers are one of the specialty amplifiers from Analog Devices, Inc., used to amplify small differential signals in the presence of large common-mode voltages. A typical application for a current sense amplifier is amplifying the voltage across a shunt resistor. This application note details how to set-up for, and measure the current-mode step response of ADI’s current sense amplifier portfolio.
The AD7403/AD7405 are high performance, second-order, Σ-Δ modulators that convert an analog input signal into a high speed, single-bit data stream, with on-chip digital isolation based on Analog Devices. Inc., iCoupler® technology. This application note describes a method of using a collocated, system integrated, temperature sensor with the AD7403/AD7405 devices to calibrate out a large degree of offset and gain error drift over temperature.
Variable dynamic range (VDR) provides an efficient, non- obstructive technique to provide wideband, high resolution, and fast sample rate to digital predistortion (DPD) observation receivers. In this application, nonlinearities are measured and digitally corrected such that overall intermodulation performance is significantly better than that of the core signal chain while at the same time boosting amplifier efficiency.
This application note demonstrates the implementation of an I2C interface between the ADE7953 (the slave) and the ADuCM360 (the master), using C programming language. The ADE7953 is a single-phase energy metering IC, and the ADuCM360 is an ARM® Cortex®-M3-based microcontroller.
This application note explains several aspects of the digital filtering associated with the Σ-Δ modulators used in the ADE7912/ADE7913. The role of the filters is to decimate the outputs of the modulators to various rates, while eliminating high frequency noise. These rates start from a high of 8 kHz and go as low as 1 kHz, allowing the user to update the rates to the microcontroller processing bandwidth.
The AD1933/AD1934/AD1938/AD1939/AD1974 family of codecs, ADCs, and DACs have a standalone mode of operation that allows them to be used without a microcontroller. This application note details a low cost solution for booting up these parts in any desired mode of operation. For this example, a Microchip® PIC12(L)F1571/PIC12(L)F1572 is used to boot up the AD1938 and also provides for a mute function. This part is very low cost and is available through normal distribution channels. It is offered in a variety of packages to meet the cost/size needs of most applications.
This application note describes how to connect evaluation boards and how to easily start collecting high accuracy, digital temperature readings from the ADT7310 and ADT7410 sensors using the Cortex-M3® based precision Analog Devices Inc., microcontrollers, such as the ADuCM360.
This application note provides appropriate design formulas and considerations for designing the ADP5070/ADP5071 in one of the least understood, yet most commonly used, dc-to-dc converter topologies, the SEPIC configuration.
This application note discusses the important considerations that system designers need to be aware of when using ferrite beads in power supply systems, including response characteristics of the ferrite bead, a simplified ferrite bead model and simulation, dc current considerations, LC resonance effects, and damping methods.
This application note examines specific layout options and component selection to achieve radiated emissions standards EN55022/CISPR22 Class A (FCC Class A) emissions standards commonly used in industrial environments, and EN55022/CISPR22 Class B (FCC Class B) standards in an unshielded environment, for the ADM2582E/ADM2587E RS-485/RS-422 transceivers.
This application note looks at some basic filter key specifications concepts, a few types of frequently used filter responses, a Chebyshev Type 1 filter application, and step-by-step instructions on how to transfer a single-ended filter design to a differential filter design. A differential filter design example is in this application note as well as a few points on how to optimize differential circuit PCB design.
The ADA4571 is an analog anisotropic magnetoresistive (AMR) angle sensor consisting of a sensing element and a conditioning analog instrumentation amplifier. This application note discusses various simple calibration procedures to reduce the angle linearity error from the device.
This application note describes the IEEE 802.15.4g (15d4g) firmware download module for the ADF7023-J transceiver IC. The firmware module adds the following features: IEEE 802.15.4g physical layer header formatting and data whitening, transmitter/receiver rolling data buffer, 4‑byte to 1000-byte preamble, and ARIB STD T108 compliant clear channel assessment. The ADF7023-J low power, 902 MHz to 958 MHz transceiver contains a custom microcontroller core with mask ROM that implements packet handling functions and translates radio commands into internal control sequences. An additional 2 kB of program RAM is available and serves as program code memory, which enables the radio controller commands that provide modified or extended functionality. The IEEE 802.15.4g firmware download module described in this application note is based on program code downloaded into the program RAM.
This application note describes the AD_15d4g firmware download module for the ADF7023-J transceiver IC. This firmware download module adds the following features to the ADF7023-J: IEEE 802.15.4g physical layer (PHY) header formatting, IEEE 802.15.4g data whitening, Tx/Rx rolling data buffer, 1 byte to 1000 byte Tx preamble, ARIB STD T108 clear channel assessment (CCA), and Rx antenna diversity.
Most current sense amplifiers are capable of handling high common-mode voltages (CMVs) but not high differential input voltages. In certain applications, there are fault conditions wherein the differential input voltage at the shunt exceeds the specified maximum voltage of the amplifier. These conditions can cause damage to the amplifier. This application note introduces two basic overvoltage protection circuits for current sense amplifiers and discusses the effects of the circuits on device performance for two types of current sense architectures—a current sense amplifier (using the AD8210 as an example) and a difference amplifier (using the AD8418 as an example).