Tag Archives: Switching

Step‐up DC/DC converters with built‐in inductors and control ICs

Measuring 2.5×2.0×1.0mm, the newly‐developed XCL102/XCL103 series of step‐up micro DC/DC converters is designed with built‐in inductors and control ICs. By Julien Happich @ edn-europe.com:

The use of built‐in inductors also allows PCB layouts to be simplified, minimizing unwanted radiation noise and operational trouble. The input voltage can be selected from 0.65V (operation hold voltage) to 6.0V, and the output voltage from 2.2V to 5.5V

Step‐up DC/DC converters with built‐in inductors and control ICs – [Link]

1.2V-32V @3A Variable Switching Regulator using LM317

The circuit presented here is based on LM317. Generally, LM317 is known as a linear regulator IC, but here the circuit operates as a switching regulator. This circuit operates by transferring energy
from the input to the output by using a solid state switch. Power Efficiency of a switching regulator is much higher than the linear regulators. The input voltage for this circuit is 8V-35V and it can produce the output of 1.8V to 32V, that can be varied by using potentiometer R3.

Features

  • Input(V): 8VDC to 35VDC
  • Output(V): 1.8VDC to 32VDC
  • Output load: 3A
  • PCB:68mm X 50mm

1.2V-32V @3A Variable Switching Regulator using LM317 – [Link]

Multiphase, 60V synchronous boost controller peaks at 97%

LTC3897 is a multiphase synchronous boost DC/DC controller with input surge stopper and ideal-diode controller. The boost controller drives two N-channel power MOSFET stages out-of-phase to reduce input and output capacitor requirements, enabling the use of smaller inductors versus the single-phase equivalent. By Graham Prophet @ edn-europe.com:

Synchronous rectification increases efficiency, reduces power loss and eases thermal requirements. The input surge stopper, with adjustable clamp voltage, controls the gate of an external N-channel MOSFET to protect against high input voltage transients of greater than 100V and provides inrush current control, overcurrent protection and output disconnect. The integrated ideal diode controller drives another N-channel MOSFET for reverse input voltage protection and voltage holdup or peak detection.

Step Up DC-DC Converter – 12V TO 28V DC 175mA

The Step-Up DC-DC Converter project provides 28V, 175mA output with input of 12V DC. The MC34063A IC is heart of the project from On semiconductor. The MC33063A is a monolithic control circuit containing the primary functions required for DC-DC converters. This device consist of an internal temperature compensated reference, comparator, controlled duty cycle oscillator with an active current limit circuit, driver and high current output switch. This IC specially designed to be incorporated step-down, step-up, and voltage-inverting applications with minimum number of external components.

Features

  • Input 12V DC
  • Output 28V, 175mA
  • Output Voltage  Adjustable By On-board Preset
  • Header Connector for Output/Input Connections
  • Low Standby Current

Step Up DC-DC Converter – 12V TO 28V DC 175mA – [Link]

12V to 24V 1A DC-DC Boost Converter using LM2588

12V To 24V Booster is based on LM2588 IC from Texas Instruments. The LM2588 regulator integrated circuit specifically designed for fly-back, step-up (Boost) , and forward converter. The board provides 24V DC 1A DC output, Input 8V to 16V DC. Board has minimum components, screw terminal provided for input & outputs.

Features

  • Supply Input 8V To 16V DC ( Ideal 12V DC)
  • Output 24V 1A

12V to 24V 1A DC-DC Boost Converter using LM2588 – [Link]

2.7V-4.2V input to 3.3V output Buck-Boost Converter

This project shows a DC-DC buck boost circuit which can produce an output of 3.3V for an input of 2.7V to 4.2V , for example from a Li-on battery. The Circuit uses LTC3440 Buck boost IC which is a fixed frequency boost converter. To get high efficient results, inductor with high frequency core material should be used.

Features

  • Input(V): 2.7V DC to 4.2V DC
  • Output(V): 3.3V DC
  • Output load: 600mA
  • PCB:23mmX15mm

2.7V-4.2V input to 3.3V output Buck-Boost Converter – [Link]

LT8390 – 60V Synchronous 4-Switch Buck-Boost Controller with Spread Spectrum

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The LT8390, is a synchronous buck-boost DC/DC controller that can regulate output voltage, and input or output current from input voltages above, below and equal to the output voltage. Its 4V to 60V input voltage range and 0V to 60V output voltage range are ideal for voltage regulator, battery and supercap charger applications in automotive, industrial, telecom and even battery-powered systems. The LT8390’s 4-switch buck-boost controller, combined with 4 external N-channel MOSFETs, can deliver from 10W to over 400W of power with efficiencies up to 98%. Its buck-boost capability is ideal for applications such as automotive, where the input voltage can vary dramatically during stop/start, cold crank and load dump conditions. Transitions between buck, buck-boost and boost operating modes are seamless, offering a well regulated output even with wide variations of supply voltage. The LT8390 is offered in either a 28-lead 4mm x 5mm QFN or thermally enhanced TSSOP to provide a very compact solution footprint. [source]

LT8390 – 60V Synchronous 4-Switch Buck-Boost Controller with Spread Spectrum – [Link]

LTC3786 – Efficient boost controller takes the heat

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Linear Technology has launched a higher-temperature 150°C version of its LTC3786 step-up DC/DC controller that boasts 98% efficiency. This H-grade device replaces the boost diode with an N-channel MOSFET for higher efficiency and reduced power loss. by Susan Nordyk @ edn.com:

The controller produces a 24-V, 5-A output from a 12-V input with up to 98% efficiency, useful for automotive, industrial, and medical applications. It operates from an input voltage ranging from 4.5 V to 38 V during startup, maintains operations down to 2.5 V after startup, and regulates an output voltage as high as 60 V. Its low quiescent current of 55 µA helps extend the run time of battery-powered applications in standby mode.

LTC3786 – Efficient boost controller takes the heat – [Link]

$14.5 All-Purpose Switched-Mode Power Supply

Switching technology devices and integrated circuits are growing fast providing solutions that obtain power for different kind of circuits and devices, and they are proposed in different variations. A useful little known kind which is suitable for mixed supply systems is called SEPIC,single-ended primary-inductor converter.

Torpedo is a switched-mode power supply with a SEPIC configuration which is produced by Open Electronics, an open source solutions producer and the brainchild of Futura Group Srl. It supports three different wide-range voltage sources, battery, USB, and external source from 3 to 20 volts with up to 1 A output current and integrated LiPo battery cell charger.

Torpedo Board
Torpedo Board

Torpedo comes with these features:

  • Triple power source, that is to say: the USB, the battery and an external one
  • Wide range of values as for the input voltage: from 3 to 20 volts
  • Minimum output current of 500mA, with the possibility to reach 1A and more, via an external source
  • High efficiency, above 70% and possibly above 80-90%
  • Single-cell LiPo battery charger incorporated
  • A transition from battery power to another source that is without interruptions
  • 5 V output with high stability, having a low ripple and when varying the load.

Torpedo’s circuit structure can be functionally divided into three different parts; Input Stage, Battery Charger, and SEPIC Converter.

At first, the Input Stage is composed of two diodes and a MOSFET transistor. This set forms a power source selector by allowing the highest voltage power source to pass through Vin pin and prevent it from going to another input having a lower voltage.

Torpedo Circuit Diagram
Torpedo Circuit Diagram

The Battery Charger is based on the MCP73831-2 integrated circuit, that is envisaged for charging single-cell LiPo batteries having a voltage of 4.2 volts. It comes with a red LED indicating the statues of charging, and a two-resistor bridge giving two different output current, 100mA and 500mA.

The SEPIC Converter in general is a DC/DC converter which control its output to be greater than, less than, or equal to that at its input. In Torpedo circuit, the SEPIC integrated circuit contains 1.2Mhz oscillator with variable duty cycle, a low-RDSON MOSFET, and a feedback circuit. This combination provides constant 5V output voltage from variant input voltage between 2.5V to 20V.

Torpedo is available for $14.5 from Open Electronics store, and its technical details are reachable here.

Dual input, 2.5A step-down DC/DC achieves 95% efficiency

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by Graham Prophet @ edn.com:

LTC3126 is a 2.5A, 2.4V to 42V input, synchronous step-down switching regulator with integrated dual input PowerPath control. Its power stage topology enables operation from either of two independent power sources, with seamless, internally controlled transitions between inputs to ensure a stable output voltage during hot-plug and power source disconnect events.

Dual input, 2.5A step-down DC/DC achieves 95% efficiency – [Link]