The differences among all versions of LS7634 and LS7635 are:

LS7634 (LS7634FO)

Upon power-up, the TRIG output is Off.

(Upon power-up, the TRIG output is On at maximum conduction angle.)

When a LONG touch is applied, the dimming direction automatically re-

verses whenever maximum or minimum conduction angles are reached.

LS7635 (LS7635FO)

Upon power-up, the TRIG output is Off.

(Upon power-up, the TRIG output is On at maximum conduction angle.)

When a LONG touch is applied, the dimming stops whenever maximum

or minimum conduction angles are reached. In order to change dimming

levels from maximum or minimum, LONG touch must be removed and

reapplied.The purpose of this feature is to allow the user to positively

locate maximum and minimum conduction angles.

TABLE 1

MODE

SHORT TOUCH

LONG TOUCH

DIMMING

REVERSAL

PRE-TOUCH Ø

POST-TOUCH Ø

PRE-TOUCH Ø

POST-TOUCH Ø

(Note 5)

OFF

MAX(Note 1)

OFF/MIN

Varies up from MIN

N/A

0

ON

OFF

MAX

Varies down from MAX

N/A

INTERMEDIATE

Varies from INTERMEDIATE

NO

OFF

MEMORY

OFF

Varies from memory (Notes 2, 3,4)

YES

1

(Notes 2, 3)

MIN

Varies up from MIN

N/A

ON

OFF

MAX

Varies down from MAX

N/A

INTERMEDIATE

Varies from INTERMEDIATE

YES

OFF

MAX (Note 1)

OFF/MIN

Varies up from MIN

N/A

2

ON

OFF

MAX

Varies down from MAX

N/A

INTERMEDIATE

Varies from INTERMEDIATE

YES

Note 1:

A soft turn-on is produced by slewing up the conduction angle, ø, from minimum at the rate of 1.4

Note 2:

A soft turn-on is produced by slewing up ø, from minimum to memory.

Upon power-up the memory value is defaulted to maximum conduction angle.

Note 3:

“Memory” refers to the conduction angle, ø, which existed prior to the current off-state.

Note 4:

A soft turn-on is produced by slewing up ø from minimum to memory upon which the dimming is started.

Note 5:

NO = Dimming direction does not reverse from prior dimming direction.

YES = Dimming direction does reverse from prior dimming direction. N/A = Does not apply.

7634/7635-010906-2

LS7635 NOTE:

If the User applies a LONG Touch when the TRIG Conduc-

tion Angle is within a “few” degrees of Maximum or Mini-

mum, the TRIG Conduction Angle can move to Maximum or

Minimum and stop without the User being able to observe a

change in brightness. There-fore, the User should be in-

structed that if no change in brightness is observed in re-

sponse to a LONG Touch, the LONG Touch should be re

moved and reapplied in order to produce a change in bright-

ness.

ABSOLUTE MAXIMUM RATINGS:

PARAMETER

SYMBOL

VALUE

UNIT

DC supply voltage

+7

V

Any input voltage

V

Operating temperature

0 to +90

°C

Storage temperature

-65 to +150

°C

DC ELECTRICAL CHARACTERISTICS:

PARAMETER

SYMBOL

MIN

TYP

MAX

UNIT

CONDITION

Supply voltage

4.5

5.0

5.5

V

-

Supply current

-

300

400

µA

Output unloaded

SYNC Lo

-

-

2.1

V

-

SYNC Hi

2.9

-

-

V

-

EXT, SENS Lo

-

-

1.5

V

-

EXT, SENS Hi

3.5

-

-

V

-

TRIG Lo

-

0.2

-

V

-

TRIG Hi

-

5.0

-

V

-

TRIG Sink Current

35

-

-

mA