STMicroelectronics Introduces New Alternating Current Switches
STMicroelectronics introduced a new generation of Alternating Current Switches (ACS™) to control the numerous ac loads employed by appliance applications. Designed to drive pumps, fans, valves, relays, dispensers, door locks, and micro-motors in appliances such as dishwashers, air conditioners, washing machines, dryers, refrigerators, ovens, and freezers, the new ACSes provide designers with higher voltage capability while ensuring overall system reliability and efficiency.
The 600V-rated ACS family of switches is built with ST's proprietary Application Specific Devices (ASD) process technology, which enables the integration of both over-voltage protection circuitry, and RC-snubber external components. The ACS family helps users save space within electronic boards while meeting the requirements of the latest home-appliance energy-saving and Electromagnetic Compatibility (EMC) standard for testing and measurement techniques such as IEC 61000-4-5.
An evolutionary advance over the previous ACS102-5Tx and ACS108-5Sx, the new ACS102-6Tx and ACS108-6Sx switches include improved static and dynamic characteristics. Among these, the latching and holding current levels have been reduced by 50%, allowing a more optimized gate pulse-control mode, especially in case of lower power rated loads, thus drastically reducing power consumption. The switching capabilities and the electrical noise immunity have also been improved by about 15% as compared to the previous version. Another major benefit of the recently introduced ACS devices is the crowbar structure, which starts to protect the system at a higher voltage level than the previous version. As a result, the devices' robustness has been re-qualified to enable the switches to safely sustain a higher level of energy. The company claims that designers using the new ACSes will be able to cut the cost of their appliances by reducing component count up to 80% and by avoiding external over-voltage suppressors. Appliance design will also be simplified by enabling the ACSes to be directly driven from microcontrollers.
The ACS102 is available in both TO-92 and SO-8 ECOPACK® packages, while the ACS108 is assembled in TO-92 and SOT-223 ECOPACK® packages. In production now, the ACS102 and ACS108 cost $0.23 and $0.25, respectively, in 10,000 unit quantities.
