With many years of experience in the design of power management devices, Holtek has announced its entry into the ac-dc converter arena, with the release of two new ac to dc converter power management devices, the HT7A3942 and HT7A6003.
According to the company, the HT7A3942 and HT7A6003 are presently the only devices in the world which are fully pin compatible with the UC3842, which meet Energy Star 2.0 standby specifications and which have fully integrated ac-dc converter functions. The UC3842 device is unable to provide exceptionally low operating and standby current specifications, operate with a Green Mode nor operate at very low temperatures. Additionally the present ac-dc converter devices on the market are not fully pin compatible with the UC3842 device.
As well as being fully pin and functionally compatible with the UC3842, the HT7A3942 also contains additional functions such as extra low operating and standby current specifications, a non-audible noise Green Mode extra low temperature operating specifications (-40°C for normal operation), short circuit protection etc. Products which use the original UC3842, to be replaced by the Holtek devices, need no modifications to their circuits, neither do they require additional costs to achieve the additional functions mentioned above. Additionally, the new Holtek devices also meet with Energy Star 2.0 specifications with an input voltage range of 90~265Vac and less than 0.3W of standby power for an application power range of between 0~250W.
In addition, the additional external components required by the UC3842 to implement functions such as slope compensation and leading edge blanking are fully integrated within the HT7A3942, allowing it to only require 55% of the external BOM count required by that of the UC3842.
The HT7A6003 contains all the functions of the HT7A3942 but also includes mechanisms for suppression of EMI and frequency jitter. A soft-start function is also provided to prevent circuit damage resulting from overly high voltage rise times during power on. Furthermore, an over-voltage protection (OVP) function is also provided to prevent unstable system situations or circuit damage resulting from excessively high input voltages. The high level of functional integration and multiple protection features in the HT7A6003 are particularly suitable for use in applications requiring high power stability such as the LCD TVs, LED TVs, UPS products and E-bike chargers etc.
To assist with product development, a Demo Board and Evaluation Board is also available for the HT7A3942/HT7A6003 devices, With a standby power specification of under 0.3W and efficiency reaching 88% the devices fully meet with the demands of commercial products.
