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POWER SUPPLIES 800-W and 1500-W PSUs provide constant current output down to near zero volts XP Power has introduced the HDS series of 800W and 1500W programmable AC-DC power supplies with a typical efficiency of up to 93%. The single output low profile supplies measure 249.0x127.0x40.9mm for the 800 Watt models and 280x127x63.5mm for the 1500 Watt range and fit into an industry standard 1U or 2U profile. Two front mounted variable speed fans, included in the above dimensions, help conserve energy and keep noise to a minimum. The power density of these compact units is greater than 10 Watts per cubic inch. Both the output voltage and output current are programmable from 0% through to 105% of stated nominal through a serial RS232 interface, I2C interface, a 0 to +5 VDC input or via an external potential divider. By programming the output current a true constant current output is achieved down to almost zero volts, this being better than the industry norm which is typically only down to 20-40%. The HDS series comprises seven models covering the popular nominal outputs from +12 to +60 VDC. The output voltage for both series can also be manually adjusted +/- 5% by a trim function in order to make up for line losses. Both ranges also provide a user selectable standby output of 5 VDC / 0.5 Amp or 9 VDC / 0.3 Amp when the AC input is present. XP Power www.xppower.com IEC-certified X-capacitor discharge IC saves time, cuts design complexity and reduces cost Power Integrations’ CAPZero automatic X-capacitor discharge IC is now certified to meet IEC CTL DSH 1080, the new mandatory addition to the Certification Body (CB) scheme of the IEC60950 and IEC60065 standards governing X-capacitor discharge safety regulations. CAPZero ICs are simple, SO-8-packaged, two-terminal devices that require only the addition of discharge resistors to automatically implement the X-capacitor discharge function. New power supplies must comply immediately with the IEC CTL DSH 1080 requirement, which ensures that a power supply’s Xcapacitor safety-discharge function remains operational over the life of the product. CB-certified X-capacitor discharge devices such as CAPZero pass a stringent safety-testing protocol including a lengthy period of high-temperature and high-humidity testing and high voltage line-surge testing. Power supplies using a certified X-capacitor discharge device are deemed automatically compliant. Power supplies not utilizing a CB-certified device, including those using discrete components or other non-certified ICs, must pass the same environmental tests as well as line-surge testing with all protection devices such as varistors and bulk capacitors removed. Any redesign would result in a need for re-certification of the power supply. Power Integrations www.powerint.com 80-V battery charging controller actively finds true maximum power point in solar panels Linear Technology Corporation has released a synchronous buck-boost battery charging controller for lead acid and Lithium batteries which features automatic maximum power point tracking (MPPT) and temperature compensation. The LT8490 operates from input voltages above, below or equal to the regulated battery float voltage. The LT8490’s full-featured battery charger offers many selectable constant-current constant-voltage (CC-CV) charging profiles, making it suitable for charging a variety of Lithium or lead acid chemistry types, including sealed lead acid, gel cells and flooded cells. All charge termination algorithms are provided onboard, eliminating the need for software or firmware and thus reducing design cycle time. The LT8490 operates over a wide 6 V to 80 V input voltage range and can produce a 1.3 V to 80 V battery float voltage output using a single inductor with 4-switch synchronous rectification. The device is capable of charging currents as high as 10 A depending on the choice of external FETs. The LT8490’s MPPT circuit enables a sweep of the full operating range of a solar panel, finding the true maximum power point, even in the presence of local maxima points caused by partial shading of the panel. Once the true maximum power point is found, the LT8490 will operate at that point while using a dithering technique to quickly track changes in the local maximum power point. With this methodology, the LT8490 fully utilizes the power generated by a solar panel even in non ideal operating environments. Linear Technology www.linear.com 864W quarter-brick DC/DC module for datacom supplies Ericsson has introduced a hybrid regulated ratio DC/DC converter that handles 864W: the PKM-NH platform quarterbrick module delivers high power density of 35.6W/cm3, with a flat-curve, high-efficiency of up to 97% The second product in the high-power PKM-NH format, the PKM4817NH-PIHS is optimised for datacom board applications that have a 52–58V system bus distribution and require high-power regulated quarter-brick-format intermediate bus converters. The PKM-NH follows the PKM4717NH, which has highpower handling capability of 750W. To meet the challenge of packing this level of power into a fully regulated quarterbrick format DC/DC converter, Ericsson has deployed its proprietary topology known as Hybrid Regulated Ratio (HRR). The topology combines two power-control methods – voltage-regulation and ratio-regulation – resulting in high performance across the input voltage ranges between 40V to 60V, which are commonly used in datacom systems. The PKM4817NH-PIHS module delivers an output voltage from 8.6V to 10.8V at a maximum output current of 80A across an input voltage range of 40V to 60V, within the operational system voltage between 36V and 60V. PKM4817NH has a typical efficiency of 97% at 50% load and offers flat-curve characteristics from 20A to 60A. Ericsson www.ericsson.com 42 Electronic Engineering Times Europe December 2013 www.electronics-eetimes.com


EETE DEC 2013
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