Holtek is pleased to announce the release of its new HT7L4813 and HT7L4815 non-isolation buck type AC-DC converter devices specifically designed for applications such as tube, bulb and general lighting etc. The devices meet the requirements for high efficiency LED lighting control applications.
A 500V high voltage power MOSFET is integrated into the devices reducing the requirement for this external power component. The HT7L4813 internal power MOSFET switch on resistance is 6Ω and the system output power can reach 12.5W@150mA for a voltage range of 85-265Vac and 17.6W@150mA for a voltage range of 180-265Vac. For the HT7L4815, the internal power MOSFET switch on resistance is 2.5Ω and the system output power can reach 8.3W@300mA for a voltage range of 85-265Vac and 21W@300mA for a voltage range of 180~265Vac.
With their high output current accuracy of ±3% and high power factor values exceeding 0.9, these new devices also possess the advantages of ambient temperature change insensitivity as well as having easy setup system parameters. Their unique current control methodology can control LED current values accurately to ensure the system is able to maintain stable LED current output conditions, even under conditions of input voltage variations, the number of LED outputs or inductor tolerances.
By operating in the boundary conduction mode with its high power factor characteristic, the devices can operate with minimum system switching losses thus offering enhanced EMI characteristics. Their ultra-low start-up current of 10uA and low operating current also helps to improve system efficiency. Several protection functions are also included such as Output Short Protection, Cycle by Cycle Current Limit, Output Over Voltage Protection, Over Voltage and Over Temperature protection to ensure safe and reliable operation.
With regard to packaging the devices are supplied in a 8-pin SOP package. The above mentioned features combine to provide ideal solutions for high efficiency and low cost power conversion applications.
