TIMING CHARACTERISTICS (See Figures 2, 3 and 4):

PARAMETER

SYMBOL

MIN

TYP

MAX

UNIT

CONDITION

SYNC Frequency

fs

40

-

70

Hz

-

SHORT Touch

42

-

333

ms

60Hz

50

-

400

ms

50Hz

LONG Touch

342

-

infinite

ms

60Hz

410

-

infinite

ms

50Hz

TRIG pulse width

Tw

-

130.2

-

µs

60Hz

Tw

-

156.2

-

µs

50Hz

Conduction Angle

ø

41

-

158

deg

-

ø incremental steps

∆ø

-

1.4

-

deg

-

(Note 1)

Soft-on slew rate

-

1.4

-

deg/8.33ms

60Hz

-

1.4

-

deg/10ms

50Hz

A0 to A1/A2 to A0 slew rate

-

1.4

-

deg/33.3ms

60Hz

(Note 2)

-

1.4

-

deg/40ms

50Hz

A1 to B1/B2 to A2 slew rate

-

1.4

-

deg/66.7ms

60Hz

(Note 3)

-

1.4

-

deg/80ms

50Hz

B1 to B2 delay

-

500

-

ms

60Hz

(Note 4)

-

600

-

ms

50Hz

Note 1: Total nimber of steps = 83

Note 2: Number of steps from A0 to A1 or A2 to A0 = 68

Note 3: Number of steps from A1 to B1 or B2 to A2 =15

For LS7632 when minimum ø is reached, dimming direction reverses only if the LONG Touch is terminated and reapplied.

7631-120505-3

ø

TRIG

SYNC

FIGURE 2. TRIG OUTPUT CONDUCTION ANGLE,

ø

150º

100º

50º

OFF

150º

100º

50º

OFF

150º

100º

50º

OFF

Ø

MODE Ø

Ø

MODE 1

Ø

MODE 2

SENS

342ms

SHORT

SHORT

LONG

SHORT

LONG

SHORT

LONG

A2

B2

B1

A1

A0

A2

B2

B1

A2

B2

B1

A1

A0

A0

A0

A1

A2

A2

MEMORY

REVERSE

REVERSE

SLOPE = Ss

FIGURE 3. LS7631 TRIG,

DISCUSSION: REPLACEMENT FOR SLB0587

There are minor design differences between LS7631 and SLB0587

requiring component value changes to the external application circuitry.

• The LS7631 SENS and EXT input switching levels differ from SLB0587.

This can require external input resistor ratios to be changed.

• The LS7631 PLL characteristics differ from the SLB0587. In order to

achieve optimum PLL stability, LS7631 requires a 0.02uF Filter Cap

Filter Cap with a series 330k Ohm resistor connected between

Adjusting the application circuit for these differences will result in LS7631

functioning the same as SLB0587.