Solutions Search - Extended Temperature Plastic (H & MP)
Improving Linearity by Using Absorptive Filters
Mar 10th 2017
Introduction:
When driving a direct sampling high speed ADC, the most likely place to degrade the performance is the interface between the final amplifier and the ADC. With any direct sampling ADC there will be nonlinear charge produced in the sampling process. This charge is reflected into the input network each time the sampling ...
High Voltage, High Efficiency Positive to Negative Converter
Mar 8th 2017
Design Note 561: Introduction
Positive to negative conversion (inverting output) is widely used in LCD devices, OLED displays, audio amplifiers, industrial machinery, semiconductor manufacturing process control equipment, measurement tools, testing systems, LED drivers and battery chargers. Many of these applications require ...
Using the LTC6820 with the LTC24XX Delta Sigma Family
Feb 8th 2017
Introduction
The LTC6820 isoSPI isolated communication interface is typically used in automotive applications. One of the more popular applications is to isolate the battery monitor circuits. However, it can be a desirable solution for medical applications where isolation is necessary. Another advantage for the LTC6820 is to ...
Maximizing Cell Monitoring Accuracy and Data Integrity in Energy Storage Battery Management Systems
Jan 24th 2017
Grid-connected battery arrays are viable backup and carry-through power sources; application-specific measurement ICs which meet their unique and sophisticated requirements ensure reliable system performance.
The use of large-scale battery arrays for backup and carry-through energy storage is getting increasing attention, as ...
High Linearity, Low Noise LTC2387-18 Drivers for Sinusoidal Signals
Jan 10th 2017
Introduction
The LTC2387-18 is a high speed SAR (Successive Approximation Register) ADC suited for high linearity, low noise applications. This ADC is capable of sampling at up to 15Msps, which allows it to convert signals at frequencies of several MHz. It is well-suited to convert both pulsed and continuous signals in this ...
2500VRMS Isolated RS485+RS232 Transceiver with Power
Nov 23rd 2016
In this circuit, the LTM2887-3S µModule isolator provides isolated signaling and power to the LTC2873 for a complete, 3.3V robust, galvanically isolated dual-protocol transceiver. RS232 (transmit and receive) or RS485 (half-duplex) can be selected for transmission on a single pair of wires using the 485/232 control. Mode-specific ...
2500VRMS Isolated PROFIBUS RS485 Transceiver with Power
Nov 23rd 2016
In this circuit, the LTM2887-3S µModule (micromodule) isolator provides isolated signaling and power to the LTC2876 for a complete, 3.3V robust, galvanically isolated transceiver. LTC2876 is a PROFIBUS RS485 transceiver designed to meet the specifications for PROFIBUS-DP masters and PROFIBUS-DP slaves, fully compatible ...
Hybrid Wide Dimming Ratio Linear LED Current Controller Using LT8614 & LT3083/LT6015
Oct 17th 2016
Many applications for LED illumination require wide dimming ratios. This can be accomplished simply via an adjustable current source as show below. The current source can be varied by a number of different means, and a large LED current range can be achieved. The primary problem with this technique is that the power dissipation ...
Low EMI LED Driver Features 2A, 40V, Integrated, Synchronous Switches for Automotive Lighting
Oct 12th 2016
Design Note DN557: Introduction
The breadth of LED applications has grown to encompass everything from general lighting to automotive, industrial and test equipment, sign boards and safety instruments. Feature requirements for LED drivers have become more extensive. The latest LED solutions require drivers that are compact, ...
Clever Circuit Improves Efficiency of Charge Pump Plus Linear Regulator Solution
Oct 4th 2016
In some systems, a charge pump plus linear regulator combination is preferred over an inductor-based switching power supply (with or without a post-regulating linear regulator) for several reasons: design simplicity, less radiated EMI, inductor-phobia, etc. For these applications, Linear Technology has a growing number ...
3A, 1MHz Buck Mode LED Driver with Integrated Voltage Limiting
Oct 3rd 2016
Design Note DN556: Introduction
The LT3952 monolithic LED driver includes a 4A, 60V DMOS power switch, excellent for driving high current LEDs in buck mode. Among its many features is an input current sense amplifier, which can be leveraged to provide built-in LED voltage limiting in buck mode.
In buck mode, the ...
LT3759 Wide Vin, 48V @ >100mA Output Boost Converter that Works Down to 1.6V
Oct 3rd 2016
The LT®3759 is a wide input range, current mode, DC/DC controller which is capable of regulating either positive or negative output voltages from a single feedback pin. It can be configured as a boost, SEPIC or inverting converter. An internal LDO regulator draws power from VIN or DRIVE to provide up to a 4.75V supply for ...
Op Amp Precision Positive & Negative Clipper using LT6015/LT6016/LT6017
Oct 3rd 2016
It can be a challenge to match the voltage range of an analog signal to the input range of an analog to digital converter (ADC). Exceeding the ADC’s input range will give an incorrect reading, and if the input goes far enough beyond the power supply rails substrate currents can flow into the ADC which can cause latch up ...
Single-Ended to Differential Driver Circuit for the LTC2387-18 SAR ADC
Sep 26th 2016
The LTC®2387-18 is a 15Msps, highly linear, low-noise SAR converter with differential inputs. The combination of excellent linearity and wide dynamic range makes this ADC ideal for high speed imaging and instrumentation applications. No-latency operation provides a unique solution for high speed control loop applications. ...
LTC2387 Drivers Part III: Trans-Impedance Amplifier/Driver
Sep 8th 2016
This is unabashedly a classic case of what marketing calls “a solution looking for a problem”. It is an example of how the full SNR of the LTC2387 may be realized for a real world signal. Most signals originating in low level circuitry, in sensors, or in the real world, will require significant gain to develop 8Vp-p ...
Build a Precision Low Noise 5A Power Supply
Sep 6th 2016
The LT6658-2.5V voltage reference has the specifications of a precision reference with dual outputs capable of 150mA and 50mA. This unprecedented combination of precision and power allows the unique ability to create a very precise high-current power supply with load regulation of less than 12ppm/A. Only a few additional components ...
How NOT to Damage Your Switching Regulator Demo Board
Sep 2nd 2016
Introduction:
A great way to develop a design is to start with an existing demo board and modify it. While this simplifies the process, there are a few pitfalls to be aware of so that you do not have to spend time tracking down and replacing damaged components. Below are four common ways to damage your circuit.
1) Improper ...
I2C Primer: What is I2C? (Part 1)
Sep 2nd 2016
Introduction:
The Inter-Integrated Circuit (I2C) bus is a two wire serial interface originally developed by the Phillips Corporation for use in consumer products. It is a bi-directional bus that is easily implemented in any IC process (NMOS, CMOS, bipolar) and allows for simple inter-IC communication. Connections are minimized ...
Active Battery Cell Balancing
Aug 18th 2016
With passive and active cell balancing, each cell in the battery stack is monitored to maintain a healthy battery state of charge (SoC). This extends battery cycle life and provides an added layer of protection by preventing damage to a battery cell due to deep discharging over overcharging. Passive balancing results in all ...
Passive Battery Cell Balancing
Aug 18th 2016
In the automotive and transportation marketplace, large battery stacks provide high output power without producing harmful emissions (i.e. carbon monoxide and hydrocarbons) associated with gasoline-powered combustion engines. Ideally, each individual battery in the stack equally contributes to the system. However, when ...
Consequences of Not Following the Data Sheet Bypass Recommendation
Aug 8th 2016
I occasionally get customers who ask me to review their ADC schematics and often I will see that the values for the bypass capacitors for Vdd and Vref are smaller than the data sheet recommendations. Here is an experiment I would like to share to show why it is important to use the suggested bypassing values. The circuit of ...
Anti-Alias Filter for 24-bit ADC
Aug 3rd 2016
For many ADC applications a simple RC filter at the buffer input will provide adequate anti-alias filtering. For applications that require a higher order filter an active filter is often used. The active component in that filter must have sufficient bandwidth, fast settling, low noise and low offset so that it doesn’t ...
LTC6244 High Speed Peak Detector
Aug 1st 2016
Introduction
Peak detectors capture the extrema of the voltage signal at its input. A positive peak detector captures the most positive point of the input signal and a negative peak detector captures the most negative point of the input signal. Ideally the output of the peak detector circuit tracks or follows the input voltage ...
Baseband Design Example for LTC5589/LTC5599 Low-Power IQ Modulator
Jul 1st 2016
Introduction
This basic low power modulator was described in the LT Journal Nov 2015 article. In this blog post, we will show how to:
Use simulation to validate the filter design, and
Reduce DC offsets by utilizing Differential Amplifiers for the baseband drive.
Also shown are some miscellaneous tips to help complete ...
95% Efficient at 2MHz 42V Sync Buck
Jun 24th 2016
Linear Technology’s family of high voltage synchronous step-down DC/DC switching regulators offer up to 95% efficiency. Switching at 2MHz, these low EMI parts utilize the Silent Switcher technology. Other features include spread spectrum frequency modulation, ultra-low quiescent current and are available with single, dual, ...
No-Opto Isolated Flyback Converters
Jun 10th 2016
The no-opto isolated flyback parts from Linear need no opto-coupler or LT1431 shunt regulator for regulation. They sense the isolated output voltage directly from the primary-side waveform. This simplifies the design, allows for a smaller solution size and only requires one component crossing the isolation barrier. The load, ...
LT6703 AC Line Overcurrent Indicator
Jun 4th 2016
Circuit Description
This circuit design is to monitor the average current in an AC line-connected load and to illuminate an LED if it exceeds a specified level.
µPower, Low Voltage Comparator with Reference
The basis of this design is the LT6703-2 which combines a micropower, low voltage comparator with a 400mV reference ...
LTspice: Using Time-Dependent Exponential Sources to Model Transients
May 15th 2016
When working with Surge Stoppers or Hot Swap Controllers, occasionally there is a need to simulate a circuit's behavior with a specified voltage or current transient. These transients are usually modeled using a double exponential waveform characterized by a peak voltage, a rise time (usually 10%–90%), a fall time to 50% ...
How to Drive the LTC2387 (Part 1): Signal Applications to 5MHz that Require Low Inter-Modulation Distortion
May 13th 2016
The biggest challenge in driving a 15Msps, 18-bit ADC with an 8Vp-p input range is the lack of integrated amplifiers with adequate bandwidth, low noise, and the required output excursion. There are low-noise, high-BW amplifiers than can produce 2VPP. There are low speed amplifiers than can produce 8VPP. For low distortion beyond ...
Primer on PowerPath Controllers, Ideal Diodes & Prioritizers
Apr 29th 2016
Electronic systems powered by multiple DC sources are commonplace - they include handheld devices (USB port and battery), portable instruments (wall adapter and battery), and high-availability servers (main and redundant/auxiliary supply rails). Selecting the correct input supply to power the system is not a trivial ...
Common Questions About the LTC2668 Family of 16bit VOUT DACs
Apr 19th 2016
The LTC2668-16 packs 16, 16-bit high performance Digital to Analog converters (DACs) into a tiny, 6x6mm QFN package, with 8 and 4 channel versions in a 5x5 QFN, and 12-bit versions for lower resolution applications. A general purpose DAC such as this finds its way into a myriad of diverse applications, and tends to generate ...
AN159: Measuring 2nV/√Hz Noise and 120dB Supply Rejection on Linear Regulators - The Quest for Quiet
Apr 4th 2016
AN159: Introduction
A quiet, well regulated supply is important for optimum performance with a number of circuit applications. Voltage controlled oscillators (VCOs) and precision voltage controlled crystal oscillators (VCXOs) respond to small changes in their supply very quickly. Phase-locked loops (PLLs) require a stable supply ...
LTSpice: Plotting a Parameter Against Something Other Than Time (e.g. Resistance)
Mar 25th 2016
A common use for LTSpice® is to run a time domain transient analysis where a parameter (e.g. voltage or current) can be plotted against time. Occasionally, you may wish to know the behavior of a circuit versus another parameter such as resistance. This can be done by using the “.measure” and “.step” ...
A New Era in Space Products - Radiation Tolerant
Mar 23rd 2016
Recent developments have made doing business in space ever more achievable to a broadening base of companies. A market previously consisting solely of major defense contractors and national governments has been disrupted by a growing list of commercial companies determined to deploy an enterprise beyond the confines of our ...
Differences Between the Ćuk Converter and the Inverting Charge Pump Converter
Mar 7th 2016
The Ćuk converter (also referred to as the two inductor inverting converter), the inverting charge pump and the single inductor inverting converter (also referred to as the inverting buck-boost) all provide a negative output voltage from a positive input voltage. However, engineers often unknowingly refer to these topologies ...
Powering Altera Arria 10 FPGA and Arria 10 SoC: Tested and Verified Power Management Solutions
Feb 19th 2016
Design Note DN549: Introduction
FPGA development kits allow system developers to evaluate an FPGA without having to design a complete system. Figures 1 and 2 show Altera’s new 20nm Arria 10 FPGAs and Arria 10 SoCs (System-on-Chip) development boards. These boards are tested and verified by Altera, exemplifying best design ...
High-Voltage Amplifier Extends Coulomb Counter Range to +/-270V
Jan 22nd 2016
Introduction
A coulomb counter can measure charge that flows into or out of a battery. Small, dedicated devices such as LTC2941 or LTC2943 can directly interface with low to medium battery voltages, up to about 20V. You can extend the input operating range of the measurement circuit by using a high-voltage amplifier as a level ...
Shutdown with the LT3080x Current Source Reference Linear Regulators
Jan 21st 2016
Current Source Reference Linear Regulators
In many low noise applications, a linear regulator is an ideal solution for the power conversion due to its very low output voltage noise and low electromagnetic noise generation (compared to a charge pump or a switching regulator). The LT308x linear regulator family is ideal for these ...
VID Controller with Phase Extender Provides 120A Power Supply for Latest Generation of FPGAs, ASICs and Processors
Jan 12th 2016
DN547: Introduction
The current drawn by FPGAs, ASICs and processors for high performance servers, network and computing systems continues to rise, and load currents of 100A or greater are becoming common. Meanwhile, the chip's operating voltages are dropping to 0.9V and below with tighter voltage regulation requirements. For ...
Spread Spectrum Frequency Modulation Reduces EMI
Nov 4th 2015
Electromagnetic Radiation (EMR), Electromagnetic Interference (EMI) and Electromagnetic Compliance (EMC) are terms that pertain to energy from electrically charged particles and the associated magnetic fields that can potentially interfere with circuit performance and signal transmissions. With the proliferation of wireless ...
Parameters that Affect Comparator Propagation Delay Measurements
Nov 4th 2015
One of the key specifications for a comparator is propagation delay - the amount of time it takes for a signal propagate from the comparator input to the output. Whether as a threshold detector in a battery powered application, or on a high speed signal processing board, the comparator's propagation delay is often the first ...
Low Power, Precision Op Amp Simplifies Driving of MUXed ADCs
Oct 2nd 2015
Design Note 1034: Introduction
The high speed op amps required to buffer a modern 16‑/18-bit analog-to-digital converter (ADC) typically dissipate as much power as the ADC itself, often with a maximum offset spec of about 1mV, well beyond that of the ADC. If multiple multichannel ADCs are required, the power dissipation can ...
Injection-Lock a Wien-Bridge Oscillator
Sep 22nd 2015
I recently had the opportunity to investigate a new micropower 6-MHz LTC6255 op amp driving a 12-bit, 250k sample/sec LTC2361 ADC. I wanted to acquire the FFT of a pure sinusoid of about 5 kHz. The problem is that getting the FFT of a pure sinusoid requires, well, a pure sinusoid. Most programmable signal generators, however, ...
Signal Conditioning for High Impedance Sensors
Sep 22nd 2015
Abstract
Dealing with high impedance sources and maintaining high impedance inputs without compromising reliability has its own set of challenges. This article offers qualitative and quantitative discussions of issues associated what high impedence circuits, what types of sensors are high impedance, and what devices are available ...
Signal Level Shifting with μModule Regulator for Positive-to-Negative Inverting Appliications
Sep 3rd 2015
Introduction
Linear μModule regulators are perfect for point-of-load supplies because their easy-to-drop-in, compact, all-in-one design. They fit tight spaces with minimal engineering effort—only a few components are required in addition to the µModule package itself. Any step-down µModule ...
Positive to Negative Converter with Variable Output Using LTC3630 and LT6015/LT6016
Sep 1st 2015
There was a window of time in the 1950s and early ’60s when negative voltage rails were commonplace, when germanium PNP transistors were prevalent—like those used in an old “transistor radio”, now worth a fortune on Ebay. Nowadays, NPN transistors are more prevalent, since they basically work ...
Data Backup Solution for 1mm, Low Profile Industrial Applications
Aug 25th 2015
Introduction
Data backup and retention during a power interruption is required in a wide variety of industrial and automotive applications, where emergency backup power supplies (such as a UPS) may be unfeasible. For example, a vehicle may need to transmit geographical coordinates and the vehicle ID during an abrupt battery ...
Robust 140V VIN, 400mA Step-Down Regulator for Industrial, Telecom and Automotive Environments
Aug 20th 2015
Design Note 543: Introduction
The LTC®7138 is a 400mA step-down regulator that can operate over an input voltage range of 4V to 140V, ideal for industrial, telecom, automotive and other applications subject to harsh line transients. Due to the regulator’s hysteretic architecture, no external compensation is required. ...
Increasing Output Current of the Ultralow Noise, Ultrahigh PSRR LT3042 200mA Linear Regulator
Aug 17th 2015
The LT0342 is a 200mA, 1.8V to 20V input, linear regulator that targets low noise RF and wireless circuits. It features an industry-leading 0.8µVRMS output noise (10Hz to 100kHz) and an impressive 79dB PSRR at 1MHz. Several customers have asked for ways to increase the current above 200mA while still maintaining low noise ...
Achieving Low On-Resistance with Guaranteed SOA in High Current Hot Swap Applications
Jul 29th 2015
Introduction
The requirement for live insertion and removal in high current backplane applications demands MOSFETs that exhibit both low on-resistance during steady state operation and high Safe Operating Area (SOA) for transient conditions. Often, modern MOSFETs optimized for low on-resistance are unsuitable for high SOA Hot ...
100V Micropower Voltage Monitor Provides Flexible Monitoring of Positive and Negative Rails Simultaneously
Jul 22nd 2015
Flexible supply monitoring that eases design and provides high accuracy, at a low current cost, is in high demand in today’s power conscious world. Typical supply monitors comprise a comparator with a reference, and an external divider to set the exact trip points. Unfortunately, the divider can, itself, draw more current ...
Paralleling Amplifiers Improves Signal-to-Noise Performance
Jul 9th 2015
Dealing with low amplitude signals can be challenging. In order to differentiate between the low level signal and the noise contributed by surrounding circuitry, we typically use gain to amplify the signal above the noise floor. However, a standard amplifier configuration multiplies the input signal, the input noise, ...
Micropower Op Amp Drives 8-Channel 18-Bit Simultaneous Sampling ADC without Compromising Accuracy or Breaking the Power Budget
Jun 23rd 2015
Design Note 541: Introduction
The op amps used to drive 18-bit analog-to-digital converters (ADCs) typically draw as much supply current as the ADC itself, often with a maximum offset spec that is well above that of the ADC. If multiple ADC channels are required, the power dissipation from these drivers quickly rises to unacceptable ...
36V Input, 8.5A Buck-Boost μModule Regulator Easily Parallels for Increased Power
Jun 16th 2015
Design Note DN540: Introduction
The LTM®8055 is a buck-boost μModule® regulator with a 5V to 36V input range that can be easily paralleled to extend load current capability. Its 4-switch buck-boost topology features high efficiency while allowing the input voltage to be below, at or above the output—with smooth ...
Paralleling Linear Regulators Made Easy
May 21st 2015
Linear regulators provide a simple, low noise solution for dc-dc regulation. However, at higher Vin-Vout differentials the low efficiency and high power dissipation of linear regulators limits the ammount of output current that can realistically be delivered. Connecting multiple linear regulators in parallel spreads the ...
Sometimes You Need a Little Gain Part 2
Apr 28th 2015
Introduction
Part 1 of "Sometimes You Need a Little Gain" dealt with a pseudo-differential ADC driver with gains of one to ten. This time a fully differential ADC driver, again with gains of one to ten will be described. First a brief recap on the LTC2373-18 SAR ADC and a description of the LTC6237 op amp which will be ...
Sometimes You Need a Little Gain - Part 1
Apr 9th 2015
Introduction
The LTC2373-18 is an 18-bit, 1Msps, 8-channel SAR ADC with an integrated high performance reference and programmable sequencer. The LTC2373-18 can be configured to accept both pseudo-differential (unipolar and bipolar) and fully differential input signals. For best performance, an op amp should ...
Paralleling Amplifiers Increases Output Drive
Apr 1st 2015
There are several circuit techniques that increase the output drive capability of an amplifier. One method uses external bipolar transistors as a push-pull circuit to provide additional drive. Another method uses two different amplifiers in a composite amplfier configuration as detailed in Application Note 21 to leverage ...
Avoid Amplifier Output Driver Saturation When Using pA Bias Current Amplifiers with High Source Impedance Sensors
Mar 26th 2015
Need for Low Bias Current Amplfiers
When taking sensor measurements, the type of sensor excitation used varies greatly; it can be a DC signal, an AC signal, a voltage source, a current source or a pulsed source to name a few. When using current source excitation or when using a high impedance sensor, the amplifier's bias current ...
Multiple LTC2315-12 ADCs Share SPI Bus
Mar 18th 2015
The data sheet doesn’t always show everything you need to know about using a part. For example, a common application when using multiple serial ADCs is to share the clock and data output lines to simplify the interface to the processor/ FPGA. The data sheet for the LTC2315-12 12-bit 5Msps, SPI compatible ADC with an integrated ...
Accurate, Fast Settling Analog Voltages from Digital PWM Signals
Mar 17th 2015
Introduction
Pulse width modulation (PWM) is a common technique for generating analog voltages from a digital device such as a microcontroller or FPGA. Most microcontrollers have dedicated PWM generation peripherals built in, and it only takes a few lines of RTL code to generate a PWM signal from an FPGA. This is a simple, ...
LT6703 μPower Supply Voltage Monitor with 2V Hysteresis
Mar 17th 2015
The LT6703 µPower, low voltage comparator and reference offers a single comparator and accurate reference in a 2mm × 2mm DFN package. The -3 version is has a non-inverting input. Although only one of its comparator inputs is accessible (the other is connected to a 400mV internal precision voltage reference) its size ...
Buck-Boost μModule Regulator's External Current Sense Resistor For Paralleling ICs, Current Sharing and Overcurrent Protection
Mar 17th 2015
Linear Technology's µModule 4-switch buck-boost regulators provide an integrated, high-efficiency solution for applications where the input voltage can be either above or below the desired output voltage. These fixed frequency, current mode devices require only a few external components to provide a minimal design ...
LTC4226 Parallel MOSFETs in Hot Swap Circuits
Mar 13th 2015
The Good, the Bad, and the Ugly
Introduction
While it is often desirable, and sometimes absolutely critical, to use multiple parallel MOSFETs in Hot Swap™ circuits, careful analysis of Safe Operating Area (SOA) is essential. Each additional parallel MOSFET added to a circuit improves the voltage drop, power loss, and ...
LTC3890 & LTC4000 60V Input DC/DC Power Supply with Battery Backup
Feb 27th 2015
Introduction
Circuitry presented in this article can be very useful for designing compact power supplies and extremely beneficial for system functioning in conditions of input power interruptions. The presented solution can be embedded into uninterruptible power systems or small standalone modules. It can be successfully employed ...
LT3753 9V-15V Input to 54V/3A Isolated Forward Converter
Feb 26th 2015
The LT®3753 is a primary side, current-mode PWM controller optimized for an active clamp forward converter topology. It features a programmable volt-second clamp that provides a duty cycle guardrail to limit primary switch reset voltage and prevent transformer saturation during load transients. The LT3753 also features ...
Understanding Power Monitor Accuracy
Feb 20th 2015
Measurement of a system’s power consumption during a final factory test (before deployment into the field) is a prudent part of a test program for any product. But there is an increasing emphasis to bring this functionality into the product itself for “run-time” monitoring of power, current, supply voltage, ...
Transimpedance Amplifier Noise Considerations
Feb 18th 2015
The LTC6268 and LTC6269 is a single/dual 500MHz FET-input operational amplifier with extremely low input bias current and low input capacitance. It also features low input referred current noise and voltage noise making it an ideal choice for high speed transimpedance amplifiers, CCD output buffers, and high-impedance ...
Increase Amplifier Output Drive Using a Push-Pull Amplifier Stage
Feb 17th 2015
Many portable circuits require precision measurement capability along with low power operation to minimize current and battery drain. When searching for an amplifer with these requirements, it may be relatively easy to meet the low power and precision requirements, but the drive current may not be adequate for these low power ...
LT3752/LT8311 48Vin, 24Vout Active Clamp Forward Converter with High Light Load Efficiency
Feb 11th 2015
The LT3752 includes a number of programmable features that make it suitable for this application. For instance, programmable delays between various gate signals is used to prevent cross-conduction and to optimize efficiency, and programmable turn-on current spike blanking (adaptive leading edge blanking plus programmable extended ...
LT3798/LT8309 5V, 2A Energy Star Compliant Isolated Converter
Feb 10th 2015
The focus of this circuirt was to take a design based on the LT®3798 and make it Energy Star Compliant; reduce no load, standby power to less than 300mW. That was achieved by adding the components highlighted in the dotted line box in the schematic inside the primary side. This circuit is simply a switch that removes ...
LT8310/LT1431 81 Watt Isolated Nonsynchronous Forward Converter with Opto Feedback
Jan 30th 2015
The LT8310 is a constant-frequency resonant reset forward converter controller with a low side N-channel MOSFET gate driver. The LT8310 has a wide input voltage range from 6V to 100V. Its switching frequency can be programed from 100kHz to 500kHz to optimize efficiency, performance or external component size. The LT8310's protection ...
Loop Gain and its Effect on Analog Control Systems
Jan 26th 2015
Abstract
This article brings together the ideas of open loop gain, closed loop gain, gain and phase margin, minimum gain stability and shows how these parameters are interrelated in a feedback system. It examines loop gain in terms of a theoretical control system as well as practical electronic circuits, including linear regulators.
Introduction
Bob ...
Precision Op Amp Enables Fast Multiplexing at Low Power
Jan 23rd 2015
Introduction
If you are designing a system that measures a number of analog voltages, but not all at the same time, you can reduce downstream circuitry by multiplexing the measurements into a single output signal, then serially process and digitize the original voltage levels using shared components. The benefit is that the ...
LT3790 240W High Efficiency Parallel Buck-Boost Regulator
Jan 5th 2015
The LT3790 is a 4-switch synchronous buck-boost DC/DC converter that regulates both constant voltage and constant current at up to 98.5% efficiency using only a single inductor. It can deliver hundreds of watts and features a 60V input and output rating, making it an ideal DC/DC voltage regulator and battery charger ...
Surge Stoppers Ease MIL-STD-1275D Compliance
Nov 25th 2014
Introduction
A military vehicle is a tough environment for electronics, where the potential for damaging power supply fluctuations is high. U.S. Department of Defense MILSTD- 1275D sets down the requirements for electronics when powered from a 28V supply, ensuring that electronics survive in the field.
MIL-STD-1275D compliance ...
Robust High Voltage Over-The-Top Op Amps Maintain High Input Impedance with Inputs Driven Apart or When Powered Down
Nov 5th 2014
Introduction
Linear Technology’s Over-The-Top op amps have an input stage topology that allows them to operate closed loop well above the positive supply rail. The inputs remain high impedance when split apart in voltage and also when shut down or with complete loss of power supply. They are indispensable in robust ...
Output Voltage Noise Measurements for Linear Regulators
Sep 20th 2014
Linear regulators provide a simple, non-switching DC/DC converter solution with low component count, small solution footprint and low output voltage noise. These attributes make them well-suited for applications that have power supply noise constraints, have limited board space and are averse to magnetics. Applications ...
High Efficiency 100mA Synchronous Buck Converter with Wide Input Range from 4V to 150V
Sep 17th 2014
Introduction
The wide 4V to 150V input range of the LTC®3639 stepdown DC/DC converter allows automotive, avionics and distributed power systems to:
Cover extensive transient requirements
Enable multiple wide-ranging input power sources, such as a high voltage DC bus with a low voltage battery backup
Create a ...
LT3752/LT8311 240W Isolated Forward Converter
Jul 28th 2014
The LT3752 includes a number of programmable features that make it suitable for this application. For instance, programmable delays between various gate signals is used to prevent cross-conduction and to optimize efficiency, and programmable turn-on current spike blanking (adaptive leading edge blanking plus programmable extended ...
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