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]
by Steve Taranovich @ edn.com:
With many switching buck regulators on the market today that are capable of improving an automotive system design it is hard to choose the optimum one for your design. I patricularly like a new Linear Technology solution, the LT8609, a 2A, 42V input synchronous step-down switching regulator because it is unique in that it does not require an external flyback diode (sometimes called a snubber diode, freewheeling diode, suppressor diode, suppression diode, clamp diode or catch diode) which is a diode used to eliminate flyback, which is the sudden voltage spike seen across an inductive load when its supply voltage is suddenly reduced or removed. This makes for less external components.
Linear Technology 2A buck converter is 93% efficient at 2MHz - [Link]
Micrel’s family of low-profile step-down power modules integrates a synchronous buck regulator with an inductor into a 2.5×3×1.1-mm QFN package for the 1-A MIC33163/33164 and a 2.5×3×1.9-mm QFN package for the 2-A MIC33263/33264. The modules offer 100% duty cycle operation and accommodate an input voltage range of 2.7 V to 5.5 V.
DC/DC buck power modules fit tight spaces - [Link]
by Steve Taranovich @ edn.com:
A circuit or system designer’s job is a difficult one. Fraught with design compromises to be made and challenges to overcome that are sometimes seemingly insurmountable. That’s why our personalities are programmed to solve problems and “Think outside the box”. The best designers don’t even know there is a box!
I see so many new product offerings every day that “fill a hole in our line” or are simply another op amp or regulator for the portfolio among a sea of analog and power devices out there. I turn away the great majority of these so-called “new” products because my readers need innovative solutions with options that can meet their many and varied design needs. Time to market is the mantra in the industry.
Power management for wearables: Designer options - [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]
Adding to their ever growing family of power supply regulators Linear Technology have introduced the LTC3807 step-down switching regulator DC/DC controller driving an all N-channel external synchronous power MOSFET stage. The chip uses a constant frequency current mode architecture allowing a phase-lockable frequency of up to 750 kHz.
The chip draws just 50 μA no-load quiescent current and an OPTI-LOOP compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. The LTC3807 features a precision 0.8 V reference and power-good output indicator.
Low-loss Step-down Regulator - [Link]
Ken Shirriff has a great post on his blog about reverse engineering how a 7805 voltage regulator works:
Under a microscope, a silicon chip is a mysterious world with puzzling shapes and meandering lines zigzagging around, as in the magnified image of a 7805 voltage regulator below. But if you study the chip closely, you can identify the transistors, resistors, diodes, and capacitors that make it work and even understand how these components function together. This article explains how the 7805 voltage regulator works, all the way down to how the transistors on the silicon operate. And while exploring the chip, I discovered that it is probably counterfeit.
Reverse Engineering A Counterfeit 7805 Voltage Regulator - [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]
To add to its growing family of voltage regulator solutions Linear Technology Corporation have announced the LT3061, a high-voltage, low-noise, low-dropout voltage linear regulator with active output discharge. The device can deliver up to 100 mA of continuous output current with a 250 mV dropout voltage at full load. The LT3061 features an NMOS pull-down that discharges the output when SHDN or IN is driven low. This rapid output discharge is useful for applications requiring power conditioning on both start-up and shutdown (e.g. high-end imaging sensors).
A single external capacitor provides programmable low noise reference performance and output soft-start functionality. The LT3061 has a quiescent current of 45μA and provides fast transient response with a minimum 3.3μF output capacitor. In shutdown the quiescent current is less than 3μA and the reference soft-start capacitor is reset.
A High Voltage LDO regulator - [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]