LS7540

www.DataSheet4U.com LSI/CSI UL ® LS7540 (631) 271-0400 FAX (631) 271-0405 LSI Computer Systems, Inc. 1235 Walt Whitman Road, Melville, NY 11747 A3800 TOUCH CONTROL CONTINUOUS DIMMER with AUTOMATIC GAIN CONTROL (AGC) June 2006 FEATURES: Touch or pushbutton control of incandescent lamps. Touch Sensitivity guaranteed to 600pF Touch Plate Capacitance. Touch Operation independent of line plug polarity. Minimal external components. AGC Loop stabilizes immediately after Power-Up. Brightness state is Off after AC power applied. No change of Brightness state if AC power interrupted < 0.5 sec Advanced CMOS design for reliable operating characteristics and low power. 50/60 Hz Line Frequency. 5V Operation (VDD - VSS). LS7540 (DIP); LS7540-S (SOIC) - See Figure 1 APPLICATIONS: Screw-in and built-in adapter modules for converting table and floor lamps to touch control for continuous dimming. DESCRIPTION: The LS7540 is a CMOS integrated circuit for controlling the brightness of incandescent lamps with momentary touch. When its TOUCH input is connected to a lamp body, the entire lamp turns into a touch plate. A built-in AGC circuit allows for a wide range of lamp sizes to be used, ranging from very small table lamps to very large floor lamps. The brightness is controlled by controlling the conduction angle of a triac in series with the lamp and triggered by the TRIG/ output. Between off and maximum, there are 124 steps of brightness levels, level zero being off a...