LSI LS7535-S, LS7535, LS7534, LS7534-S Datasheet

DIMMER LIGHT SWITCH

WITH UP AND DOWN CONTROLS

FEATURES:

• Phase-lock loop synchronization allows use as a
Wall Switch

• Brightness control of incandescent lamps with touch
plates (LS7534) or mechanical switches (LS7535)

• Dual Controls eliminate confusion

• Soft turn-on /turn-off

• Controls the "Duty Cycle" from 23% to 88%

(conduction angles for AC half-cycles between 41°
and 159°, respectively)

• Operates at 50Hz/60Hz line frequency

• Input for slow dimming

• +12V to +18V DC supply voltage (VSS - VDD)

• LS7534/LS7535 (DIP);

LS7534-S/LS7535-S SOIC - See Figure 1

DESCRIPTION:

LS7534/LS7535 are monolithic, MOS integrated cir­cuits that are designed for brightness control of in­candescent lamps. The outputs of these ICs control
the brightness of a lamp by controlling the firing an­gle of a triac connected in series with the lamp. All
internal timings are synchronized with the line fre­quency by means of a built-in phase-lock loop cir­cuit. The output occurs once every half-cycle of the
line frequency. Within the half-cycle, the output can
be positioned anywhere between 159° conduction
angle for maximum brightness and 41° conduction
angle for minimum brightness in relation to the AC
line frequency. The positioning of the output is con­trolled by applying the proper logic levels at the UP
and DOWN inputs.

These functions may be implemented with very few
interface components which is described in the ap­plication examples (See Fig. 5A and 5B). For touch
plates, LS7534 is used (Fig. 5A). For mechanical
switches, LS7535 is used (Fig. 5B).

In the following Operating Description of the applica­tion examples, an Activation is Touch for LS7534
and Switch Closure for LS7535.

Short Activation (34ms to 325ms)
UP - When the lamp is off, if a short activation is applied to

the UP input, the lamp brightness is ramped up to full-on or
to a previous brightness stored in the memory. The ramp­up time from off to full-on is 2.8 sec. The ramp-up time from

off to any other brightness is proportionally shorter. When
the lamp is on at any brightness, a short activation applied
to the UP input has no effect.
DOWN - If a short activation is applied to the DOWN input,
the lamp brightness is ramped down to off. The ramp-down
time from full-on to off is 5.6 seconds. The ramp-down time
from any other brightness is proportionally shorter. When
the lamp is off, a short activation applied to the DOWN input
has no effect.

Long Activation (Greater than 334ms)
UP - If a long activation is applied to the UP input, the lamp

brightness ramps up from the pre-activation brightness as
long as the activation is maintained or until the full bright­ness is reached. At full brightness any continued long ac­tivation has no further effect.
DOWN - If a long activation is applied to the DOWN input,
the lamp brightness is ramped down as long as the long ac­tivation is maintained or until the minimum brightness is
reached. At minimum brightness, any continued long ac­tivation has no further effect. When the lamp is off, a long
activation applied to the DOWN input has no effect.

CONNECTION DIAGRAM - TOP VIEW

LSI

1

2

3

4

8

7

6

5

LS7534

FIGURE 1

TRIG

VDD(-V )

DOWN

UP

VSS (+V)

DOZE

CAP

SYNC

August 1996

7534/35-080796-1

LSI/CSI

LSI Computer Systems, Inc. 1235 Walt Whitman Road, Melville, NY 11747 [phone] FAX [phone]

U

L

®

A3800

LS7534
LS7535

UP/DOWN SIGNAL DURATION

SHORT LONG

INPUT 34ms to 325 ms More than 334ms

UP

DOWN

PRE-ACTIVATION

BRIGHTNESS

Off

Max.

Intermediate

Off

Max.

Intermediate

POST-ACTIVATION

BRIGHTNESS

Memory **

(See Note 1)

No Change
No Change

No Change

Off *
Off *

PRE-ACTIVATION

BRIGHTNESS

Off

Max.

Intermediate

Off

Max.

Intermediate

POST-ACTIVATION

BRIGHTNESS

Increases from Min.

No change

Increases from pre-

touch brightness

No change

Decreases from Max.

Decreases from pre-

touch brightness

* 5.6 second ramp-down from max. to off. Ramp-down time from any other brightness is proportionally shorter.

** 2.8 second ramp-up from off to max.
NOTE 1: "Memory" refers to the brightness stored in the memory. The brightness is stored in memory when the
lamp is turned off by a short activation. First time after power-up, a short activation produces max. brightness.

INPUT/OUTPUT DESCRIPTION:

VSS (Pin 1)

Supply voltage positive terminal.

DOZE (Pin 2)

A clock applied to this input causes the brightness to de­crease in equal increments with each negative transition
of the clock. Eventually, when the lamp becomes off, this
input has no further effect. The lamp can be turned on
again by activating the UP input. For the transition from
maximum brightness to off, a total of 83 clock pulses are
needed at the DOZE input.
When either the UP or the DOWN input is active, the
DOZE input is disabled.

CAP (Pin 3)

The CAP input is for external component connection for
the PLL filter capacitor. A capacitor of 0.047µF ± 20%
should be used at this input.

SYNC (Pin 4).

The AC line frequency (50Hz/60Hz), when applied to this
input, synchronizes all internal timings through a phase
lock loop. The signal for this input may be obtained from
the line voltage by employing the circuit arrangement
shown in the application examples.

UP (Pin 5).

This input controls the turn-on and the conduction angle, ø ,
of the TRIG output. A description of this is provided in the
DESCRIPTION and TABLE 1. For LS7534, a logic low level
is the active level whereas for LS7535 a logic high level is
the active level. LS7535 has an internal pull-down resistor
of about 500K Ohms on this input.

DOWN (Pin 6).

This input controls the turn-off and the conduction angle, ø,
of the TRIG output. A description of this is provided in the
DESCRIPTION and TABLE 1. For LS7534, a logic low level
is the active level, whereas for LS7535 a logic high level is
the active level. LS7535 has an internal pull-down resistor
of about 500K Ohms on this input.

VDD (Pin 7).

Supply voltage negative terminal.
TRIG (Pin 8).

The TRIG output provides a low level pulse occurring every
half-cycle of the SYNC signal. The conduction angle, ø, of

the TRIG output can be varied within the range of 41o to
159o by means of either the UP or the DOWN input.

TABLE 1

7534/35-080796-2

ABSOLUTE MAXIMUM RATINGS:

PARAMETER SYMBOL VALUE UNIT

DC supply voltage VSS - VDD +20 V
Any input voltage VIN VSS - 20 toVSS + 0.5 V
Operating temperature TA 0 to +80 °C
Storage temperature TSTG -65 to +150 °C

DC ELECTRICAL CHARACTERISTICS:

(TA = 25°C, all voltages referenced to VDD)

PARAMETER SYMBOL MIN TYP MAX UNIT CONDITIONS

Supply voltage VSS +12 - +18 V ­Supply current ISS - 1.2 1.7 mA VSS = +15V,

Output off

Input Voltages:

DOZE LO VIZL 0 - VSS - 6 V -

DOZE HI VIZH VSS - 2 - VSS V ­SYNC LO VIRL 0 - VSS - 9.5 V ­SYNC HI VIRH VSS - 5.5 - VSS V ­UP, DOWN LO VIOL 0 - VSS - 8 V ­UP, DOWN HI VIOH VSS - 2 - VSS V -

Input Current:

SYNC, UP, DOWN HI IIH - - 110 uA With Series 1.5MΩ

Resistor to

115 VAC Line
SYNC, UP, DOWN LO IIL - - 100 nA ­DOZE HI IIH - - 100 nA -

DOZE LO IIL - - 100 nA -

TRIG HI VOH - VSS - V ­TRIG LO VOL - VSS - 8 - V VSS = +15V
TRIG Sink Current IOS 50 - - mA VSS = +15V,

VOL = VSS - 4V

TRANSIENT CHARACTERISTICS (See Fig. 2 and 3)
(All timings are based on fs = 60Hz, unless otherwise specified.)

PARAMETER SYMBOL MIN TYP MAX UNIT

SYNC frequency fs 40 - 70 Hz
UP, DOWN duration (SHORT) Ts1 34 - 325 ms
UP, DOWN duration (LONG) Ts2 334 - infinite ms

ø ramp time, off to max TUS - 2.8 - sec
(UP,SHORT)
ø ramp time, min to max TUL - 3.6 - sec
(UP,LONG)
ø ramp time, max to min TDS - 5.6 - sec
(DOWN,SHORT)
ø ramp time, max to min TDL - 3.6 - sec
(DOWN,LONG)
TRIG pulse width TW - 33 - µs
TRIG conduction angle (See Note) ø 41 - 159 degrees
DOZE frequency fD 0 - 500 Hz

NOTE: The phase delay caused by the typical RC network used between SYNC input and the AC line (See Fig. 5A and
Fig. 5B) reduces the effective ø values by 8°.

7534/35-080796-3