When engineers consider offline switchers for systems ranging from telecom and datacom equipment to PCs and industrial supplies, they mainly think of bulky AC/DC front-end solutions in a variety of forms such as bricks, modules, and open-frame. However, there are many applications where offline switchers powered by AC mains are needed in small packages or must occupy a small space on the motherboard. Some examples: USB adapters to power media players, e-readers, and GPS devices; and low-cost, offline LED drivers in lighting applications with high power factor to meet international requirements for total harmonic distortion (THD), EMC, and safety. Offline switchers are also used as standby power supplies in PCs and laptops, as well as in compact chargers for smartphones and other mobile devices. The point is that there are many applications where offline AC/DC switchers are needed in small form-factors.
Offline Switchers Come in Tiny Packages - [Link]
by University of Bristol:
A breakthrough in the design of signal amplifiers for mobile phone masts could deliver a massive 200MW cut in the load on UK power stations, reducing CO2 emissions by around 0.5 million tonnes a year.
Funded by the Engineering and Physical Sciences Research Council (EPSRC), the Universities of Bristol and Cardiff have designed an amplifier that works at 50 per cent efficiency compared with the 30 per cent now typically achieved.
Currently, a 40W transmitter in a phone mast’s base station* requires just over 130W of power to amplify signals and send them wirelessly to people’s mobiles. The new design, however, enables the transmitter to work effectively while using just 80W of power.
New design for mobile phone masts could cut carbon emissions - [Link]
Compact battery chargers require overcurrent protection and temperature monitoring to ensure safety. These chargers also need to fit into small form factors, and generally have a lot of pressure to also be very inexpensive, but only have to provide a simple charging ability.
Furthermore, compact packaging is required to integrate the battery charger into a system. Renesas has 8/16-bit microcontrollers available in compact packages with as few as 10 pins, making them ideal for these applications.
78K0/Kx2: 8-bit All Flash microcontroller: wealth of on-chip peripheral functions such as a reset circuit and on-chip oscillator; low power consumption,30 to 80 pins.
78K0/Kx2-L: 8-bit All Flash microcontroller: wealth of on-chip peripheral functions such as a reset circuit, on-chip oscillator, and operational amplifier; ultra-low power consumption, 16 to 48 pins
78K0S/Kx1+: 8-bit All Flash microcontroller: wealth of on-chip peripheral functions such as a reset circuit and on-chip oscillator; 10 to 30 pins
R8C Family: Timer, 5 V operation, and Small Package
P-ch MOSFET: Low on-resistance, compact low-profile
Renesas Battery Charger Solutions - [Link]
by Hua (Walker) Bai:
The meaning of the term “high power LED” is rapidly evolving. Although a 350mA LED could easily earn the stamp of “high power” a few years ago, it could not hold a candle to the 20A LEDs or the 40A laser diodes of today. High power LEDs are now used in DLP projectors, surgical equipment, stage lighting, automotive lighting, and other applications traditionally served by high intensity bulbs. To meet the light output requirements of these applications, high power LEDs are often used in series. The problem is that several series-connected LEDs require a high voltage LED driver circuit. LED driver design is further complicated by applications that require fast LED current response to PWM dimming signals.
Design Notes: 60V, Synchronous Step-Down High Current LED Driver - [Link]
By Ashok Bindra:
The use of low-dropout regulators, popularly known as LDOs, is common in many applications today because they provide a simple and inexpensive way to regulate an output voltage that is stepped-down from a higher input voltage. In addition, linear LDO voltage regulators contribute very-low noise as compared to switching regulators.
Nonetheless, to keep system power consumption low, such regulators must also feature ultra-low quiescent current (IQ) while providing excellent dynamic performance to ensure a stable, noise-free voltage rail, suitable for driving IC loads such as microprocessors, FPGAs, and other devices on the system board.
Selecting the Right Ultra-Low Quiescent-Current LDO Regulator - [Link]
Got a buck? Make a charger for LiR2032 coin cells. It could hardly be cheaper or easier.
This Lithium battery charger circuit board, based around a TP4056 chip, will set you back all of $0.90. That may be an overestimate. I won an auction this week for 5 of them and paid $1.36, shipping included.
$1 Lithium Coin Cell Charger - [Link]
By Steven Keeping:
Power management in portable devices is one of the toughest challenges faced by electronic engineers. The consumer demands instant response from their device, lots of functionality, and a large, bright and colorful touchscreen. Moreover, many of these portable devices now incorporate wireless connectivity that places further demand on the cell. And yet, the user expects the battery, a sensitive lithium ion (Li-ion) cell that requires careful recharging from a number of sources including USB sockets, to last for at least a day and then refresh quickly.
Designing a power management system to meet these conflicting problems is tough. However, there are some proven design techniques that help extend battery life. Moreover, the key semiconductor vendors have made life a little easier by offering power management units (PMUs) that integrate some, or even all, of the functionality needed for the efficient power supply of portable devices.
Design Techniques for Extending Li-Ion Battery Life - [Link]
From time to time I get requests to make some high power switching, so I decided to design a solid-state relay that could handle a lot of different situations. The most common use for it I have is refurbishing old ceramic kilns. Since our technical life is close to the stage (both theatre and music), I also wanted it to be usable as a dimmer module. And, just for kicks, as a single phase AC motor speed controller, in case we would want that.
A solid-state relay with I2C interface - [Link]
by Publitek European Editors:
Power MOSFETs have become very popular in power electronics designs because of their low capacitance and good high-frequency switching characteristics. They have reached into many applications and are helping to open up new markets in applications, from hybrid and electric vehicles through solar power to extreme-environment exploration. The unifying factor of these environments is heat. Automotive engines and solar panels can generate heat that pushes junction temperatures in power devices far higher than 100°C. Such heat can badly affect power semiconductors that are not designed to cope. Power semiconductors all have temperature limitations. Leakage current increases with temperature and this can accelerate effects that lead to breakdown conditions that can damage circuitry and cause other hazards.
MOSFETs that Can Take the Heat - [Link]
New 6W DC/DC module series TEN5 won´t be scared neither of a very fluctuating input voltage, that´s why it´s ideal even for battery-operated applications.
Series TEN5 is a well proven reliable series of insulating DC/DC modules with a fixed output voltage, in case of TEN5-2411WI it is 5V. TEN5 series is available in so to say “basic” version with a 2:1 input voltage range and also in this „WI – wide input“ version, with a 4:1 ratio. In the most of cases, it´s probably possible to choose an appropriate type, for example TEN5-1211 with an input voltage of 9-18V, which is for example ideal for 12V applications with Pb accumulators (SLA). However namely for the mobile applications it can be beneficial, if a given device could be powered also by for example 24V, used in cargo trucks.
TEN5-2411WI with an input voltage of 9-36V and 5V/1A output is suitable this new type from our stock offer. Besides mentioned wide range of input voltages it also features a good efficiency (79% typ.) and excellent regulation at a change of input and/or load. Enhanced operating temperatures range (-40 to +85°C) and resistance to a continuous shortcut make it suitable even for demanding applications. Also useful is the built-in filter to meet EN55022 Class A and FCC level A. Metal shielded package in a standard DIP-24 package with an insulated base plate simplifies PCB design and also assembly to a PCB. In the TEN5 series can be found 2 versions: with input voltages of 9-36V or 18-75VDC with various output voltages, including symmetrical ones.
Detailed information can be found in the TEN5-WI datasheet.
TEN5-2411WI – don´t be limited by an input voltage - [Link]