Touch Control Halogen Light Dimmer
(8 Pins)

Part Numbers

Category: Lighting Controls

Status: No longer in production

Stock Availability: DIP, SOIC

All of our Standard Products are RoHS Compliant

For pricing and availability you may contact us, or request a quote. Most of our standard parts are available for purchase on Digi-Key, and through our Distributors.

Features:

• Touch or pushbutton input control
• Controls high-voltage lamps and *transformer-coupled low-voltage halogen lamps. *Magnetic transformers and many electronic transformers.
• Controls Fluorescents and CFLs via dimming ballasts
• Direct replacement for P/N SLB0587
• Soft-turn on
• Automatic safety cutout
• Mode input selects LS7231, LS7232 or LS7233 type operation
• LS7631 – dimming cycles through Maximum and Minimum
• LS7632 – dimming stops at Maximum and Minimum

Description:

A typical electronic dimmer may not operate properly with the inductive load encountered when driving a magnetic transformer-coupled low voltage halogen lamp. The inductive load can cause a phenomenon called half-waving, wherein the triac fires in alternate half-cycles only, which may lead to the thermal destruction of the load transformer. The problems encountered in driving an inductive load are addressed by the LS7631/LS7632 CMOS ICs as follows:

1. Compensation for delayed triac cutoff When a trigger pulse is due to occur at a conduction angle which coincides with the on-state of the triac, the trigger pulse is delayed until the triac has turned off. This eliminates the underlying cause of half-waving.

2. Compensation for delayed triac turn-on At the set conduction angle, a triac trigger pulse of 130.2μs (60Hz) is issues by the IC. If the triac fails to fire, a second trigger pulse of 260.4μs width is issued 1ms later as a second attempt to fire the triac during the same half-cycle.

3. Safety Shutdown If the frequency of occurrences of the delayed turn-on exceeds a preset threshold, a shutdown is initiated by turning of the triac trigger pulses. The safety shutdown threshold value is accumulated in a 4-bit Up/Down counter. The count increments for every occurrence of delayed turn-on and decrements once every 8 SYNC pulses (AC line cycles). The counter will not decrement below zero. If the count reaches 15, the safety shutdown is effected.

Ordering Info

Code
Package
Notes

P/N

RoHS Compliant Standard plastic DIP

1, 2, 3

P/N – S

RoHS Compliant Standard SOIC

1, 2, 3, 4

P/N – SW

RoHS Compliant Widebody SOIC option

1, 2, 3, 4

P/N – S14

RoHS Compliant 14-pin SOIC version of 8-pin part

1, 2, 3, 4

P/N – TS

RoHS Compliant TSSOP

1, 2, 3, 4

P/N – TS24

RoHS Compliant 24-pin TSSOP version of 20-pin part

1, 2, 3, 4

Example: LSxxxx-TS = the LSxxxx in the RoHS Compliant TSSOP package-type

Note 1: See Table for package body widths

Note 2: Package outline drawings conform to JEDEC standards

Note 3: Packages shipped in anti-static tubes

Note 4: Tape and Reel option available. Contact factory for details

ADDITIONAL ORDERING OPTIONS:

Probed Wafers (P/N-PW), Waffle Packed Die (P/N-WP)

Package Body Widths
# of Pins
P/N, -C, -CM
mils
-S
mils
-SW
mils
-TS
mils

8

300

150

14

300

150

173

16

300

150

300

173

18

300

300

20

300

300

173

24

600

300

173

28

600

300

173

38

173

40

600

48

240

LSI/CSI