touch control halogen lamp dimmer ls7634/ls7635

LSI/CSI
UL
®
LS7634/LS7635
LS7634FO/LS7635FO
LSI Computer Systems, Inc. 1235 Walt Whitman Road, Melville, NY 11747
(631) 271-0400 FAX (631) 271-0405
A3800
- PRELIMINARY -
TOUCH CONTROL HALOGEN LAMP DIMMER
BACKGROUND AND GENERAL DESCRIPTION:
A typical electronic dimmer may not operate properly with the inductive load encountered when driving a 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 LS7634/LS7635
family of CMOS ICs as follows:
1. Compensation for delayed triac cut-off.
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.
With inductive loads, the holding current needed to maintain
the triac On-State, may seriously lag behind the gate trigger
signal causing the triac to turn off prematurely.
An overextented trigger signal of 500µs is produced to
compensate for the holding current delays.
3. Safety-shutdown.
If the frequency of occurrences of the delayed turn-on
exceeds a preset threshold, a shutdown is initiated by turning
off 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-shut-down is effected.
7634/7635-101205-1
V DD (+V)
1
MODE
2
NC
3
SYNC
4
LS7634
LS7635
APPLICATIONS:
Electronic dimmers for wall switch control of ceiling mounted
lighting, foot switch control of large floor lamps and hand switch
control of table lamps.
PIN ASSIGNMENT - TOP VIEW
LSI
FEATURES:
• Touch or pushbutton control of incandescent lamps
and transformer-coupled halogen lamps
• Works with Magnetic or ElectronicTransformers
• Automatic Safety Shutdown
• Three operating modes
• Extension input for remote activation
• 50Hz/60Hz AC line frequency
• +5V Power Supply (VDD - VSS)
• LS7634, LS7635 (DIP); LS7634-S, LS7635-S (SOIC);
LS7634FO, LS7635FO (DIP);
LS7634FO-S, LS7635FO-S (SOIC)
- See Figure 1 -
October 2005
8
TRIG
7
V SS (-V)
6
EXT
5
SENS
FIGURE 1
INPUT/OUTPUT DESCRIPTION:
VDD (Pin 1) Supply voltage positive terminal.
Vss (Pin 7) Supply voltage negative terminal.
MODE (Pin 2) - See Table 1
All variations of LS7634 and LS7635 can operate in 3 different
modes.
The 3-state MODE input selects the operating modes:
Vss = Mode 0; Float = Mode 1; VDD = Mode 2
SYNC (Pin 4) - See Figure 6
The AC line frequency is applied to this input. All internal timings
are synchronized to the AC. The Load On/Off status information
is also derived from this input.
SENS (Pin 5) - See Table 1
A Logic 0 applied to this input alters the TRIG output either by
turning it on, turning it off or by changing its conduction angle.
Specifically which action takes place is dependent on the type of
activation of the SENS input, namely SHORT or LONG touch
and the prior state of TRIG output.
EXT (Pin 6)
Same functionality as the SENS input, except that a Logic 1 is the
active level at this input. EXT input is intended to be operated
from a remote site with long cable connection, when noise can be
expected. The sampling method used at this input makes it less
sensitive to noise.
TRIG (Pin 8)
The TRIG output is a low level pulse occurring once every halfcycle of the AC and is intended to drive the gate of a triac in series with the load. The conduction angle, ø, of the TRIG pulse can
be varied by means of LONG and SHORT touches at either the
SENS or the EXT input.
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 reverses whenever maximum or minimum conduction angles are reached.
LS7635 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. There-fore, the User should be inLS7635 (LS7635FO)
structed that if no change in brightness is observed in reUpon power-up, the TRIG output is Off.
sponse to a LONG Touch, the LONG Touch should be re
(Upon power-up, the TRIG output is On at maximum conduction angle.)
moved and reapplied in order to produce a change in brightWhen a LONG touch is applied, the dimming stops whenever maximum ness.
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
PRE-TOUCH Ø
0
Note 1:
Note 2:
Note 3:
Note 4:
Note 5:
POST-TOUCH Ø
PRE-TOUCH Ø
POST-TOUCH Ø
DIMMING
REVERSAL
(Note 5)
OFF
ON
MAX(Note 1)
OFF
OFF/MIN
MAX
INTERMEDIATE
Varies up from MIN
Varies down from MAX
Varies from INTERMEDIATE
N/A
N/A
NO
OFF
ON
MEMORY
(Notes 2, 3)
OFF
OFF
MIN
MAX
INTERMEDIATE
Varies from memory (Notes 2, 3,4)
Varies up from MIN
Varies down from MAX
Varies from INTERMEDIATE
YES
N/A
N/A
YES
OFF
ON
MAX (Note 1)
OFF
OFF/MIN
MAX
INTERMEDIATE
Varies up from MIN
Varies down from MAX
Varies from INTERMEDIATE
N/A
N/A
YES
1
2
LONG TOUCH
A soft turn-on is produced by slewing up the conduction angle, ø, from minimum at the rate of 1.4˚/8.33ms (60Hz).
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.
“Memory” refers to the conduction angle, ø, which existed prior to the current off-state.
A soft turn-on is produced by slewing up ø from minimum to memory upon which the dimming is started.
NO = Dimming direction does not reverse from prior dimming direction.
YES = Dimming direction does reverse from prior dimming direction. N/A = Does not apply.
ABSOLUTE MAXIMUM RATINGS:
PARAMETER
DC supply voltage
Any input voltage
Operating temperature
Storage temperature
SYMBOL
VDD - Vss
VIN
TA
TSTG
VALUE
+7
Vss - 0.3 to VDD + 0.3
0 to +90
-65 to +150
UNIT
V
V
°C
°C
DC ELECTRICAL CHARACTERISTICS:
(TA = +25˚C, all voltages referenced to Vss. VDD = +5V unless otherwise noted.)
PARAMETER
SYMBOL
MIN
TYP
MAX
UNIT
Supply voltage
Supply current
VDD
IDD
4.5
-
5.0
300
5.5
400
V
µA
SYNC Lo
VISL
-
-
2.1
V
SYNC Hi
VISH
2.9
-
-
V
-
EXT, SENS Lo
VIEL
-
-
1.5
V
-
EXT, SENS Hi
TRIG Lo
TRIG Hi
VIEH
VOL
VOH
3.5
-
0.2
5.0
-
V
V
V
-
TRIG Sink Current
ITSNK
35
-
-
7634/7635-101205-2
mA
CONDITION
Output unloaded
VDD = 5.5V
-
VOTRIG = 2.5V
TIMING CHARACTERISTICS (See Figures 2, 3 and 4):
PARAMETER
CONDITION
SYNC Frequency
SHORT Touch
SYMBOL
MIN
TYP
fs
TSI
TSI
TS2
TS2
Tw
Tw
ø
∆ø
40
42
50
342
410
50
-
488
586
1.4
70
333
400
infinite
infinite
154
-
Hz
ms
ms
ms
ms
µs
µs
deg
deg
1.4
1.4
1.4
1.4
1.4
1.4
500
600
-
deg/4.17ms
deg/5ms
deg/33.3ms
deg/40ms
deg/66.7ms
deg/80ms
ms
ms
LONG Touch
TRIG pulse width (see Note 5)
Conduction Angle
ø incremental steps
(Note 1)
Soft-on slew rate
SS
SS
SAA
SAA
SBA
SBA
TBD
TBD
A0 to A1/A2 to A0 slew rate
(Note 2)
A1 to B1/B2 to A2 slew rate
(Note 3)
B1 to B2 delay
(Note 4)
-
MAX
UNIT
60Hz
50Hz
60Hz
50Hz
60Hz
50Hz
60Hz
50Hz
60Hz
50Hz
60Hz
50Hz
60Hz
50Hz
Note 1:
Note 2:
Note 3:
Note 4:
Total number of steps = 77.
Number of steps from A0 to A1, or A2 to A0 = 55.
Number of steps from A1 to B1 or B2 to A2 = 21.
ø is at minimum between B1 and B2. TBD is applicable for LS7634 only.
For LS7635 when minimum ø is reached, dimming direction reverses only if the LONG Touch is terminated and reapplied.
Note 5: TW = 130us (60Hz), 156us (50Hz) available. Contact factory for details.
FIGURE 2. TRIG OUTPUT CONDUCTION ANGLE, Ø
The information included herein is believed to be
accurate and reliable. However, LSI Computer Systems,
Inc. assumes no responsibilities for inaccuracies, nor for
any infringements of patent rights of others which may
result from its use.
SYNC
ø
TRIG
TW
FIGURE 3. LS7634 TRIG, Ø vs TOUCH (SENS OR EXT)
TS1
TS2
SENS
SHORT
SHORT
LONG
SHORT
LONG
SHORT
A0
150º
Ø
MODE Ø
50º
OFF
SLOPE = SBA
342ms
100º
A2
SLOPES = S AA
B2
A1
SLOPE = Ss
A2
B1 B2
MEMORY
A0
A0
150º
Ø
MODE 1
100º
50º
A1
OFF
B1
B2
REVERSE
A2
A0
150º
Ø
MODE 2
100º
50º
OFF
7634/7635-100105-3
B2
A2
A1
A2
B1 B2
REVERSE
LONG
FIGURE 4. LS7635 TRIG, Ø vs TOUCH (SENS OR EXT)
TS1
TS2
SENS
Ø
LONG
SHORT
SHORT
LONG
LONG
342ms
150º
100º
MODE Ø
LONG
50º
B2
LONG
SHORT
SLOPE = S BA
A0
A0
OFF
SHORT
A2
A1
SLOPE = S AA
B1
A2
B2
B2
A2
SLOPE = S S
MEMORY
MEMORY
Ø
150º
100º
MODE 1
REVERSE
50º
A1
A2
B1 B2
OFF
A2
A1
B1
B2
A0
A0
REVERSE
150º
100º
Ø
MODE 2
A0
A0
50º
B2
OFF
A2
B2
FIGURE 5. A Typical Halogen Lamp Dimmer Wall Switch
P
P
SEE NOTE 2
C5
R8
G
MT1
MT2
R7
EXTN
R3
+
C4
T
ELECTRONIC
EXTENSION
(FIG. 7)
-
Z
SEE NOTE 3
D1
L
115VAC
OR
220VAC
7
8
C2
TRIG V SS
6
5
EXT
SENS
LS7634/LS7635
V DD MODE
R2
1
2
3
4
C3
LAMP
C1 = 0.15µF, 200V
= 0.15µF, 400V
* C1
C2 = 0.15µF, 200V
* C2 = 0.082µF, 400V
C3 = 0.002µF, 10V
Component change
* = for
220VAC.
C4 = 100µF, 10V
C5 = 0.1µF, 10V
R1 = 270Ω, 1/2W
* R1 = 1kΩ, 1W
R2 = 680kΩ, 1/4W
= 1.5MΩ, 1/4W
* R2
R3 = 1.5MΩ, 1/4W
TOUCH
PLATE
NOTES
NC SYNC
R4
SEE
NOTE 4
R5
R6
C1
R1
N
A2
1) All circuits connected by broken lines are optional.
2) C5 is used only with electronic extension
and R7 is used only with mechanical switch.
3) Connection between Pin 6 & Pin 7 should
be broken when EXT is used.
4) As a precaution, transformer should have
thermal protection.
R4 = 1MΩ to 5MΩ, 1/4W
(Select for Sensitivity)
R5, R6 = 2.7MΩ, 1/4W
R6 = 4.7MΩ, 1/4W
* R5,
R7 = 150kΩ, 1/4W
R8 = 62Ω, 1/4W
D1 = 1N4148
Z = 5.6V, 1W (Zener)
T = Q4004L4 Typical Triac (1)
* T = Q5003L4 Typical Triac (1)
L = 100µH (RFI Filter)
200µH (RFI Filter)
* L(1)= For
loads greater than 6A,
use an alternistor
.
FIGURE 6.
ELECTRONIC EXTENSION
MPS8599
EXT
IN914
*R
*R
10kΩ
TOUCH PLATE
200kΩ
*R = 2M Ω for 115VAC
*R = 3.6M Ω for 220VAC
All Resistors 1/4W
P
EXTENSIONS: All switching and dimming functions can be
implemented by utilizing the EXT input. Use a pushbutton or
the electronic switch in conjunction with a Touch Plate as
shown in Figure 6. When the plate is touched, a logic high
level is generated at the EXT input of the IC for both halfcycles of the line frequency. (See Figure 5)
7634/35-101205-4
APPLICATION EXAMPLE:
A typical implementation of the light dimmer circuit is shown in Fig. 5.
Here the brightness of the lamp is set by touching the touch plate.
The function of different components are as follows:
• The 5V DC supply for the chip is provided by Z, D1, R1, C2 and C4.
• R2 and C3 generate the filtered signal for the SYNC input
AC phase synchronization.
• R3 and C5 act as a filter circuit for the electronic extension.
If extensions are not used, the EXT input (Pin 6) should be
tied to Vss (Pin 7).
• R4, R5 and R6 set up the sensitivity of the SENS input.
• R8 provides current limiting and isolation between the chip
output and the triac gate.
• C1 and L are RFI filter circuits.