Anglia Components |
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STMicroelectronics enhances VIPer family for smaller, lower-cost and more rugged power supplies
By integrating a high-voltage startup-current generator as well as essential protection functions, VIPer17 eliminates the need for external sensing components, as well as a startup resistor. Protection features include accurate, adjustable over-voltage and overload protection, hysteretic over-temperature protection, and two levels of over-current protection. Detection of a fault initiates the device’s auto-restart function, which prevents damage to the power supply or the load. An integrated soft-start function, active at startup or after a fault, reduces stress on the secondary diode and also helps prevent transformer saturation. Under light-load conditions, such as when the powered equipment is placed in standby mode, the VIPer17 automatically enters burst mode to maximize efficiency. By achieving high efficiency at sub-1W loads, VIPer17 helps designers reduce system standby power and average power consumption to satisfy energy-saving initiatives such as Energy Star and Blue Angel. The device’s typical standby power consumption is 50mW, which can be reduced to 30mW when used in an optimized transformer design. PWM operation with switching-frequency jittering also eases design challenges by reducing EMI at the switching frequency. This further extends the cost savings VIPer17 delivers in applications such as home appliances, consumer products and lighting systems, by reducing requirements for shielding. The chip comes in a low-cost 7-pin through-hole DIP package (N type) and in a surface-mounting SMD package (D type). The physical layout of the device incorporates a double island for the power MOSFET and controller, to maximize reliability under a wide range of operating conditions. Available variants are the VIPER17LN / VIPER17LD or VIPER17HN / VIPER17HD with fixed switching frequency of 60kHz or 115kHz, respectively. For more information on the full range of STMicroelectronics products available from Anglia please call +44 (0)1945 474747 or email info@anglia.com
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This news article was originally published in June 2009.
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22/6/09