Description

Since the operating currents of some electronic transformers are below the holding current of most triacs, a typical triac based (leading-edge) dimmer may not operate properly when driving an electronic transformer-coupled low-voltage halogen lamp. The filtering components in the electronic transformer which prevent its operating frequency from generating line interference can also inhibit triac triggering. The LS7636_LS7637 family of reverse-phase dimmer ICs drive FETs or IGBTs and ‘slowly’ turns on current beginning at the AC input zero-crossing. This ‘slow’ current turn on is ideal for interfacing with the primary of any electronic transformer and also eliminates the RFI generation caused by the sudden turn on of current when using a triac based dimmer.

Features:

• Push button control for direct or remote activation or touch control for direct activation.
• Controls high-voltage lamps and *electronic transformer coupled low-voltage halogen lamps. *Compatible with all electronic transformers.
• Controls Fluorescents and CFLs via dimming ballasts
• Drives FETs or IGBTs
• Reverse-phase technology eliminates RFI generation
• Soft turn-on and soft turn-off
• “FO” versions power up Full On after application of AC.
• 3-state input selects one of three modes of operation
• LS7636 P/Ns – dimming cycles through Maximum and Minimum
• LS7637 P/Ns – dimming stops at Maximum and Minimum