by Haifeng Fan @ edn.com:
Isolated DC/DC converters are required in a broad range of applications including power metering, industrial programmable logic controllers (PLCs), insulated-gate bipolar transistor (IGBT) driver power supplies, industrial fieldbus, and industrial automation. These converters often are used to provide galvanic isolation, improve safety, and enhance noise immunity. Moreover, they can be used to generate multiple output voltage rails including dual-polarity rails.
Understanding isolated DC/DC converter voltage regulation - [Link]
The NXP Flyback SMPS Design Tool helps you design flyback power supplies using NXPs TEA1721, TEA1723, TEA1733 and TEA1738 family. The TEA1721(A, B, D, F) family, the TEA1723(A, B, D, F) family, the TEA1733(A, B, C, M, L) family and TEA1738(F, G, L) family are low cost Switched Mode Power Supply (SMPS) controller IC’s intended for flyback topologies.
The latest update of the tool combines the TEA172x family and the TEA173x family into one tool. It comes along with a new style and an improved flow. Now it is also possible to export all design parameters, results and graphs automatically into an Excel sheet for post-processing or presentation purposes. Furthermore the database of transformer cores is extended.
Flyback SMPS Design Tool - [Link]
by Susan Nordyk @ edn.com:
Offered with fixed output voltages of 4.75 V, 5.0 V, 5.25 V and 5.5 V or an adjustable output voltage, the MIC2875 and MIC2876 2-MHz boost regulators from Micrel are capable of supplying up to 2 A of output current, while occupying just 122 mm2 of board space. These synchronous regulators also achieve efficiency of up to 95% and are well-suited for operation from a single-cell lithium battery and providing power to applications such as USB on-the-go and HDMI hosts, tablets, and smart phones.
The low-profile devices offer bidirectional load disconnect to prevent current flow between input and output when the regulator is disabled. Under light loads, the parts reduce the switching frequency to extend battery life. Other features include bypass mode operation when the input voltage exceeds the set output voltage and an anti-ringing switch to minimize EMI issues during discontinuous mode.
Tiny boost regulators deliver up to 10 W - [Link]
by Steven Keeping @ digikey.com
Switching DC-to-DC voltage converters (“regulators”) comprise two elements: A controller and a power stage. The power stage incorporates the switching elements and converts the input voltage to the desired output. The controller supervises the switching operation to regulate the output voltage. The two are linked by a feedback loop that compares the actual output voltage with the desired output to derive the error voltage.
The controller is key to the stability and precision of the power supply, and virtually every design uses a pulse-width modulation (PWM) technique for regulation. There are two main methods of generating the PWM signal: Voltage-mode control and current-mode control. Voltage-mode control came first, but its disadvantages––such as slow response to load variations and loop gain that varied with input voltage––encouraged engineers to develop the alternative current-based method.
Today, engineers can select from a wide range of power modules using either control technique. These products incorporate technology to overcome the major deficiencies of the previous generation.
This article describes voltage- and current-mode control technique for PWM-signal generation in switching-voltage regulators and explains where each application is best suited.
Voltage- and Current-Mode Control for PWM Signal Generation in DC-to-DC Switching Regulators - [Link]
How boost converters work and how to build a 50W adjustable boost converter circuit.
DC-DC Boost converter tutorial - [Link]
This project has been designed around Texas Instruments LM2623 IC, The LM2623 is a high efficiency, general purpose step-up DC-DC switching regulator for battery powered and low input voltage systems. It accepts an input voltage between 2.4V to 12V volts and coverts it into 5V DC. Efficiencies up to 90% are achievable with the LM2623.
2.4V to 5V Step Up DC-DC Converter - [Link]
I explain buck converters (a type of switch mode power supply) and how to build a 5V 5A power supply using an LM2678.
How to build a switch mode power supply! DC-DC buck converter tutorial! - [Link]
by BABU TA @ edn.com:
This flasher/beacon circuit can be employed as a distress signal on highways, a direction pointer for parking lots, hospitals, and hotels, etc. The circuit uses a power LED, and provides more light than a typical incandescent lamp flasher. Use of a 6V or 12V SLA lantern battery makes the circuit portable.
HB-LED flashing beacon repurposes switching regulator - [Link]
by sajjad Haidar @ edn.com:
Power supplies with adjustable DC output ranging from 0V to 30V or 60V are on the market. Above 60V, there are not many. This Design Idea offers a solution.
There are many fixed voltage switching mode power supplies (SMPS) available, and connecting several in series can give us a higher fixed voltage. To obtain an adjustable output either from a SMPS or conventional transformer based supply, one needs to use a linear regulator or a switched mode buck converter. For a buck converter, a MOSFET or an IGBT can be used as a switching element.
Usually, for a high side switch, an IC with bootsrap operation or a pulse transformer is used. There are few photovoltaic couplers available to drive MOSFETs. As they do not provide much current to charge the gate capacitance quickly, these photovoltaic couplers are mainly used to drive low frequency MOSFET switches, such as solid state relays.
Variable HV power supply employs photovoltaic optocoupler - [Link]
By Steven Keeping @ digikey.com:
Modular DC-DC switching voltage converters (or voltage regulators) are fully integrated devices that take away most of the complexity of power supply design — but not all. One of the key areas that are still left to the design engineer’s discretion is the choice of components for, and layout of, the energy storage and filtering circuits. In principle, these look like simple circuits comprising a few resistors, capacitors, and the energy-storage element, usually an inductor.
Capacitor Selection is Key to Good Voltage Regulator Design - [Link]