In this Tech Lab, we look at the evaluation board for Micrel’s MIC45212, the 14 amp variant from their line of integrated medium voltage DC-to-DC power modules.
The MIC45 205, 208, and 212 modules integrate the inductor, PWM controller, power MOSFETs, and passives into the package. This integration reduces the total application size, simplifies the design and PCB layout, and improves reliability.
By integrating the passives, Micrel is able to effectively reduce the AC loop size when compared to a traditional regulator with passives routed on the PCB.
Tech Lab – Micrel MIC45212 Evaluation Board for Medium Voltage DC to DC Power Modules - [Link]
by Dario Borghino @ gizmag.com:
A new power inverter developed at the Oak Ridge National Laboratory (ORNL) marries advances in 3D printing and wide-band semiconductor technology to deliver significantly improved performance in a smaller, lighter package. With further development, it could go a long way toward helping build electric cars that are more powerful and energy-efficient.
New power inverter could make EVs more powerful and efficient - [Link]
An application note (PDF) from MAXIM:
The typical specification for lithium coin-cell batteries has been to provide a 10-year battery lifetime in the absence of system power. End users should evaluate the anticipated lifetime in their specific application, especially for those that exceed typical commercial environments or that need to last more than 10 years. This article gives the reader an overview of the major factors affecting the lifetime of an IC that can be powered by either the system power or a lithium battery for a backup supply.
Lithium coin-cell batteries: Predicting an application lifetime - [Link]
by Steve Taranovich @ edn.com:
I have been hearing about so many different and novel techniques for battery charging and cell balancing lately. Designers are working feverishly to optimize cell balancing and battery safety along with improved efficiency. I have been closely watching Sendyne for a while now, ever since the SFP100 was chosen to be one of 2013’s EDN Hot Products and UBM ACE Award finalist in the category of Ultimate Products in Analog ICs. This IC is a current, voltage and temperature measurement solution and can be configured for automatic compensation for resistance dependence of the shunt over temperature with a separate reference design board.
Unique battery pack architecture patented by Sendyne - [Link]
Environmental energy harvesting is a possible source of power for Internet of Things (IoT) sensor nodes but needs careful management. Unless harvesters based on solar or thermal technology, for example, are designed to be compatible with conventional circuits, DC/DC converters need to be optimized for low-voltage inputs.
Sensor nodes for the Internet of Things often need to placed well away from a reliable power source but operate for many years. Although long storage-life batteries provide one option for powering these devices, an increasingly viable alternative is the use of environmental energy harvesting, using sources such as light, vibration and temperature differentials.
Power Conversion Options for Energy Harvesting IoT Nodes - [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]
The Juice4Halt module is a supercapacitor based energy storage. It contains two independent DC/DC converters. The first one is a bidirectional step-up/step-down converter working as the interface between the stable 5V supply rail and the supercapacitor. During charging the converter works in step-down mode and transports energy from the external power supply to the supercapacitor. In case of a power failure the load device (Raspberry Pi or another SBC) is supplied from the supercapacitor via DC/DC converter working in step-up mode.
The second DC/DC converter is a Front-end step-down converter. The only function is converting a high input voltage down to 5.1V for the 5V rail. It is necessary to use the Front-end converter in case of an external power supply.
The Batteryless UPS for the Raspberry Pi - [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]
Of the many low-dropout (LDO) regulators used to regulate voltage in electronic systems, some are specifically designed for low-noise operation. The MAX8887 low-noise LDO, for example, achieves a noise voltage of only 42µVRMS over the 10Hz to 100kHz range. Applications such as the ultra-low-noise oscillators required in instrumentation, however, require even lower noise. To fulfill that requirement, this project features the MAX6126 and a combination of low-noise components and filtering that achieves an output noise of only 6nV/√Hz at 1kHz
Ultra-Low-Noise LDO - [Link]
by pinomelean @ instructables.com:
Lithium based batteries are a versatile way of storing energy; they have one of the highest energy density and specific energy(360 to 900 kJ/kg) among rechargeable batteries.
The downside is that, unlike capacitors or other kinds of batteries, they can not be charged by a regular power supply. They need to be charged up to a specific voltage and with limited current, otherwise they turn into potential incendiary bombs.
And that’s no joke, storing such a high amount of energy in a small and normally tight packaged device can be really dangerous.
Li-ion battery charging guide - [Link]