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Power Supplies


for which no software programming knowledge is required. Being software programmable allows system power designers to answer questions and fill in boxes with information to create a successful initial design – the I2C interface on the IC allows continuous communications with the system so dynamic changes with operational system needs can be adjusted on the fly. Since no compensation network is needed with the usual resistors and capacitors – initial accuracy and drift over time and temperature high accuracy is reduced greatly. Additionally complex slew rate control delays and sequencing is simple to


implement. Importantly as system needs change, the power system can be reconfigured without any hardware changes, even remotely.


One of the benefits of the system level


approach to power implemented in this way is that the hardware is completely re- usable. The hardware design stays constant and reusability is easier than ever before – differentiation is achieved by defining the power system in simple software and saving it on the IC. Additionally if 3-4 or 20 or more channels are needed it’s a simple matter to daisy chain more channels and extend the system via I2C to control more channels by adding essentially more of the


same and repeating the design until the desired numbers of channels are achieved in hardware. Current levels per channel are defined in software and component selection. Differentiation is done via software so, the implementation can be reused across multiple products and product lines, and economies of scale are possible where reusing the hardware is accomplished and different products are differentiated only in software.


Power system solution approach While the needs of VLSI devices are undeniably becoming more complex, a


power system solution approach can make implementation easier. Customer benefits include the opportunity to save energy by allowing the system to modulate and optimise its own power supply to extract the best performance per watt as well as adding new features and functions. Devices like the PowerXR can be used to simplify the design of DDR3 and soon four memory systems as the programmability of the system can create the necessary delays, ramp rates on power up as well as power down. The PowerXR system can also generate the required voltages for using any termination scheme which might be desired either passive or active components which need the VTT voltage – this voltage is usually required to be precise and accurate over temperature and time. It can be seen that today’s processors also need complex accurate precise power and can also benefit from PowerXR programmable power technology. The flexibility of this approach is that channels can be added and daisy chained together to enable a system where each channel can be controlled individually regardless of how many channels are added. Channels can be added in 3 -4 channel increments. Thus an 8-channel implementation would consist of two 4-channel devices where each channel is independently designed and controlled for its unique task. A software GUI is available as well as evaluation boards and complete design assistance.


Exar Corporation | www.exar.com Kevin Parmenter is a member of Exar Corporation’s technical staff


IDEAL POWER


AC/DC POWER SUPPLIES www.cieonline.co.uk


STAGE 2


MEETS ErP


SOLUTIONS


 UL/GS/SAA/CB/K mark approved  CE/RoHS/FCC Class B compliant  From £7.45/unit for 1,000 pcs (12V 60W)  Available in quantities of 50 off upwards  12V 3.5A, 4.0A or 5.0A versions  Other models, Voltages & Power available


For the ideal solution to your power requirements call us on: T. 0845 260 3400 www.idealpower.co.uk Components in Electronics July/August 2011 31


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