The functional differences between LS7631 and LS7632 are:

LS7631 - When a LONG touch is applied, the dimming direction auto-

matically reverses whenever maximum or minimum conduction an-

gles are reached.

LS7632 - When a LONG touch is applied, the dimming stops when-

ever 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

There are a total of 84 discrete values of ø.

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.

7631/7632-111902-2

LS7632 NOTE: If the User applies a LONG Touch when

the TRIG Conduction Angle is within a “few” degrees of

Maximum or Minimum, the TRIG Conduction Angle can

move to Maximum or Minimum and stop without the User

being able to observe a change in brightness. Therefore,

the User should be instructed that if no change in bright-

ness is observed in response to a LONG Touch, the

LONG Touch should be removed and reapplied in order

to produce a change in brightness.

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