Solutions Search - Power Management
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 ...
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 Efficiency, 15V Rail-to-Rail Output Synchronous Step-Down Regulator Can Source or Sink 5A
Jan 23rd 2017
Design Note 560: Introduction
The LTC®3623 is a high efficiency, monolithic synchronous step-down regulator capable of sourcing or sinking up to 5A of continuous output current from an input voltage range of 4V to 15V. Its compact 3mm × 5mm QFN package incorporates an abundance of features including a low EMI Silent ...
Switch Mode Power Supply Current Sensing - Part 3: Current Sensing Methods
Nov 22nd 2016
The three commonly employed current sensing methods for switch mode power supplies are: are using a sense resistor, using the MOSFET RDS(ON) and using the DC resistance (DCR) of the inductor. Each method offers advantages and disadvantages that should be considered when selecting one method over another.
Sense Resistor ...
Switch Mode Power Supply Current Sensing - Part 1: The Basics
Nov 20th 2016
Current mode control is widely used for switching mode power supplies due to its high reliability, simple loop compensation design, and simple and reliable load sharing capability. The current sense signal is an essential part of a current mode switch mode power supply design; it is used to regulate the output and also provides ...
60V Input Monolithic Converter Powers Critical Circuits without Supercaps or Other Additional Components
Nov 15th 2016
Design Note DN1040: Introduction
The LTC3649 is a monolithic step-down regulator capable of operating from an input voltage range of 3.1V to 60V, and efficiently producing a (single) resistorprogrammable output voltage at up to 4A of output current. These features alone make it a compelling industrial or automotive supply for ...
Bidirectional DC/DC Regulator and Supercapacitor Charger
Nov 15th 2016
Design Note DN558: Introduction
The LTC®3110 bidirectional buck-boost DC/DC regulator charges and balances a supercapacitor when a bus voltage is present (for example 3.3V) and discharges the supercapacitor into the load when the bus fails. The LTC3110 maintains the bus’s nominal level (3.3V in the example in Figure ...
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 ...
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 ...
LTspice SOAtherm Support for PCB and Heat Sink Thermal Models
Sep 1st 2016
The SOAtherm model distributed with LTspice software and simplifies Hot Swap and Surge Stopper designs by verifying directly within a circuit simulation that a particular MOSFET’s Safe Operating Area (SOA) is not exceeded. This article assumes a basic understanding of the SOAtherm model. If you are not familiar with SOAtherm, ...
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 ...
6A Monolithic Synchronous DC/DC Step-Down Converter with Digital Power System Management
Aug 10th 2016
Design Note 554: Introduction
Digital Power System Management (PSM) controllers usually target high current point-of-load (POL) applications. Lower current applications, with up to 6A load current, can also benefit from PSM features. The LTC®3815 is a 6A monolithic synchronous stepdown converter with digital power monitoring ...
Electrolytic Capacitor-Based Data Backup Power Solution for a 12V System Regulated from 5V to 36V Input
Jul 5th 2016
Design Note 553: Introduction
Data loss is a concern in telecom, industrial and automotive applications where embedded systems depend on a consistent supply of power. Sudden power interruptions can corrupt data during read and write operations for hard drives and flash memory. Often, embedded systems need just 10ms to 50ms ...
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, ...
Inverting Regulator Takes Inputs Up to 50V and Supports Outputs to 4A
May 25th 2016
Design Note 552: Introduction
Positive-to-negative DC/DC conversion (inverting output) is widely used in LCD devices, OLED displays, audio amplifiers, industrial equipment, measurement tools, test systems, LED drivers and battery chargers. In all of these cases, the inverting converter must be compact, support high power and ...
Negative Voltage Ideal Diodes (Diode-OR Controllers)
May 23rd 2016
An ideal diode (also referred to as a diode-OR controller and more generally as a PowerPath controller) is a robust, expanded functionality replacement for a discrete power diode. It consists of a MOSFET in place of the diode to provide a low voltage drop, low power dissipation switch that connects a power ...
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% ...
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 ...
Ultrathin Triple Output μModule Regulator for DDR, QDR and QDR-IV SRAM Fits 0.5cm2 Area and Backside of PCB
Apr 18th 2016
Design Note 551: Introduction
Delivering the highest RTR (random transaction rate) of QDR (quad data rate) SRAMs, QDR-IV provides up to 400Gbps data transfer for high bandwidth networking, high performance computing and intensive data processing applications. A key challenge at these faster data rates is maintaining the integrity ...
60V, 4A Synchronous Monolithic Step-Down Regulator Has Rail-to Rail Operation
Apr 5th 2016
Design Note 550: Introduction
The LTC3649 is a high efficiency synchronous monolithic step-down regulator, which integrates top and bottom N-channel MOSFETs on the die. This regulator features a wide input voltage range, 3.1V to 60V, and a wide output voltage range from 0V to (VIN − 0.5V). This extremely wide range of ...
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 ...
42V High Power Density Buck Regulators in a Tiny QFN Package
Dec 7th 2015
Design Note 1038: Introduction
Power dissipation is a significant problem facing the designers of DC/DC converters in industrial and automotive applications, where high currents are required, but space is limited. It is possible to produce a highly efficient regulator from high performance discrete components, but expense and ...
Power Supply Sequencing Simplified
Dec 7th 2015
Design Note 1037: Introduction
Designing a multiple power supply system is challenging. The power supply designer’s workload multiplies with each additional supply rail. The designer must consider the dynamic environment of coordinated power supply sequencing and timing, generating power-on reset, monitoring for faults ...
Using a Current Sharing Controller with Non-Redundant Supplies
Nov 30th 2015
Design Note 1036: Introduction
The LTC4370 is a 2-supply current sharing, diode- ORing controller that uses MOSFETs to form ideal diodes. In this way, the LTC4370 can actively balance the output currents of two supplies, even those with unequal output voltages. For two unequal voltage input supplies, the forward voltage ...
Ultrathin Dual 2.5A or Single 5A μModule Regulator Fits on the Backside of PCBs, Allowing Space on the Topside for Digital ICs
Nov 23rd 2015
Design Note 546: Introduction
The top side of a typical system board, such as a PCIe card, is densely populated with FPGAs/ASICs/ microprocessors, transceivers, connectors, memory ICs and DC/DC regulators, while the backside is often unused. This is a common side effect of the significant difference in top vs back side height ...
Monolithic Converter Delivers High Output Voltages
Nov 4th 2015
Design Note 545: Introduction
Industrial, telecom, medical and automotive applications use a wide variety of regulated voltages to operate effectively, including high voltage and negative rails. When the designer is faced with producing industrial power supplies, the job can be simplified by minimizing the parts count, as well ...
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 ...
Optimize Sense Resistor Cost and Accuracy for RTD Temp Measurement when Using LTC2983 Temp-to-Bits IC
Oct 19th 2015
The temperature measurement using a RTD, or a Thermistor, is really a measurement of resistance. RTDs and Thermistors change their resistance with temperature. Once the resistance of the probe is measured, and assuming that the Resistance as a function of temperature is known, the temperature of the probe can be calculated. ...
Easily Boost 12V to 140V with a Single Converter IC
Sep 28th 2015
Design Note 1033: Introduction
Generating a high voltage from a much lower voltage presents a number of challenges for the classical single stage boost topology. For instance, the maximum duty cycle limitation of a boost controller may not allow the required step-up ratio. Even if it does, there is often a sharp decrease in ...
42V Quad Monolithic Synchronous Step-Down Regulator with 30μA Quiescent Current
Sep 21st 2015
Design Note 544: Introduction
Industrial and automotive applications require robust, easy-to-use, compact DC/DC converters to produce a variety of low voltage power supplies. The LT8602 monolithic quad synchronous step-down converter in a 6mm × 6mm package is capable of providing four outputs from a wide input range of ...
Using the LTC2983 with 18 2-wire RTDs
Sep 18th 2015
Introduction
A number of times I have come accross system definitions calling for use of a large number of temperature probes. Large number is in the eye of the beholder, of course, but it still brings up a question of how many sensors can interface to the LTC2983, a device that after all boasts 20 analog inputs. Well, let's ...
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 ...
Dual 9A, Step-Down μModule Regulator with Digital Power System Management
Jul 16th 2015
Design Note 542: Introduction
The LTM4675 is a dual 9A or single 18A step-down μModule® (micromodule) DC/DC regulator featuring remote configurability and telemetry monitoring of power system management (PSM) parameters over PMBus—an open standard I2C-based digital interface protocol. Its 6mm × 11.9mm × ...
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 ...
Determine Balancing Current for the LTC3305 Lead-Acid Battery Balancer
Apr 14th 2015
Design Note DN539: Introduction
The LTC®3305 is a lead-acid battery balancer that uses an auxiliary battery or an alternative storage cell (AUX) to transfer charge to and from individual batteries within a series-connected stack. The balancer controls external NMOS switches to sequentially connect the auxiliary battery ...
LT Programming Hex File Format Documentation -- In Circuit Programming
Mar 26th 2015
Purpose of Document
The purpose of this document is to clearly articulate the structure of the LT Programming Hex file in such a way that test engineers can build infrastructure to parse these files and execute programming logic to successfully program one or more LT Digital Power Product devices in cicruit, during test, or ...
LTC4218 12V / 100A Hot Swap Design for Server Farms
Mar 18th 2015
Cultivate reliability on the farm with a properly designed Hot Swap circuit.
Introduction
As data centers servicing the cloud grow in speed and capacity, backplane supplies are called on to deliver currents that push the performance boundaries of Hot Swap™ components. Hot Swap solutions allow boards to be inserted and ...
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 ...
Linduino PSM
Mar 12th 2015
While many engineers use a dongle and tools to configure Power System Management devices via PMBus, a growing number of designs are adding Board Management Controllers, or connecting their PMBus to an existing microcontroller or application processer. At LTC, the dongle/tool option is comprised of a DC1613 and LTpowerPlay, 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 ...
LTC3810 - High Efficiency Switching Surge Stopper
Feb 23rd 2015
The LTC®3810 high efficiency input limiter protects its load from excessive input voltage. At normal input voltages (<60V), it operates open loop at a very high duty cycle (>95%) to pass the input to the output at up to 5A with minimal voltage drop. When the input rises to an undesirable point (up to 75V), the ...
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, ...
17V Input, Dual 1A Output Synchronous Step-Down Regulator with Ultralow Quiescent Current
Feb 13th 2015
Design Note DN537: Introduction
The LTC®3622 dual 1A synchronous monolithic stepdown regulator enables compact, high efficiency supplies for battery powered systems and portable devices as well as general purpose point-of-load regulation. The tiny 14-pin, 3mm × 4mm DFN package takes input voltages from 2.7V to 17V, ...
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 ...
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 ...
LTspice: SOAtherm Tutorial
Oct 8th 2014
Verifying that a Hot Swap design does not exceed the capabilities of a MOSFET is a challenge at high power levels. Fortunately, thermal behavior and SOA may be modeled in circuit simulators such as LTspice IV® . The SOAtherm-NMOS symbol included in LTspice contains a collection of MOSFET thermal models developed by Linear ...
Frequently Asked Questions: LTC4010 & LTC40111 NiCd / NiMH Battery Charger
Oct 7th 2014
The LTC4010 is a complete NiMH/NiCd battery charger solution that requires no microcontroller or firmware programming. The LTC4010 includes charge initiation, monitoring, protection, charge termination and constant current control circuitry for a fast, autonomous charger solution. The IC can fast charge 1- to 16-cell NiMH ...
Frequently Asked Questions: Thermoelectric Energy Harvesting With the LTC3108 & LTC3109
Oct 6th 2014
Q. What are the target applications for the LTC3108 and LTC3109?
A. As discussed in the datasheet, these parts target applications that require a low average power (in the milliwatt range or less). This could be a micro-controller that is running continuously, or a wireless sensor/transmitter that is operating at a low duty ...
Supercap Backup Circuit Provides Reliable Uninterrupted Power
Sep 29th 2014
Temporary backup power is a common requirement for a wide range of applications whenever the main power source is suddenly unavailable. Examples include data backup applications ranging from servers to solid-state drives, power fail alarms in industrial or medical applications, and a host of other “dying gasp” functions ...
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 ...
LTC3788 Generates High Voltages Using a Two-Stage Boost Converter
Sep 17th 2014
Generating high voltages from low level sources is not an easy task. Engineers are facing the following problems when they try to implement single stage boost at high step-up ratios.
Limitation of maximum duty cycle in boost controllers
Sharp decrease in efficiency at long duty cycles
High peak currents and EMI challenges ...
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