Light Dimmers provide control via manual or uC interface.

Press Release Summary:

With supply voltage of 5 V, Model LS7642 powers up in Off state, while Model LS7642FO powers up in On state to illumination set by control voltage. Analog voltage at control input directly determines phase angle of triac trigger pulse. For automated applications, control voltage can be provided by uC, yielding accurate control of dimming patterns. For manual applications such as wall switches, wiper of sliding or rotary potentiometer can provide control voltage.

Original Press Release:

Voltage Controlled Light Dimmers

Melville, NY, - LSI/CSI announces two new innovative additions to its extensive line of Lighting Control ICs. Designated LS7642 and LS7642FO, these new ICs have been designed for easy control via manual or uC interface.

An analog voltage at the control input directly determines the phase angle of the triac trigger pulse. According to Peter Visconti, LSI's VP of Sales and Marketing, for automated applications such as emulating dawn, daylight and dusk for environments such as chicken houses, the control voltage can be provided by the uC yielding accurate control of dimming patterns. For manual applications such as wall switches, the wiper of a sliding or rotary potentiometer can provide the control voltage. Turn-on and turn-off of illumination is accomplished automatically by uC signal, or manually by pushbutton or touch sense. For both turn-on and turn-off, the brightness is softly ramped up and ramped down.

The LS7642 powers up in the Off state and the LS7642FO powers up in the On state to the illumination set by the control voltage. The LS7642FO will be desirable in parts of the world where the AC power may be interrupted several times daily.

Other features include:

o Extension input for remote turn-on and turn-off.

o Controls high voltage lighting such as incandescent and halogen lamps.

o Controls low voltage lighting such as *transformer-coupled halogen lamps

* Compatible with magnetic transformers and virtually all electronic transformers.

o Controls Fluorescents and CFLs via dimming ballasts.

o Supply voltage: 5V.

LS7642 and LS7642FO are available in 8-Pin SOIC and DIP packages.
Unit price in 10k quantity is $0.34.

The complete data sheet for these devices, as well as all of our Standard Products, can be found by visiting our Web Site, For more information, including price quotes and technical assistance, please contact


LSI Computer Systems, Inc. (LSI/CSI) began operations as the world's first fabless semiconductor company in 1969. Since its inception, LSI/CSI has been a leader in the design and production of affordable full custom and standard mixed signal, digital and analog integrated circuits. Using a broad array of process technologies, LSI/CSI has produced ICs that extend from the consumer and industrial marketplace to military and aerospace applications. The company's proven expertise and strong reputation have made LSI/CSI the IC provider of choice for leading manufacturers in a broad range of industries.

For more information, please contact:

LSI Computer Systems, Inc.

1235 Walt Whitman Road

Melville, New York 11747

Phone: 631 271-0400

Fax: 631 271-0405



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