LSI LS7231 Touch control lamp dimmer Datasheet

LSI/CSI
UL
®
LS7231-7234
LSI Computer Systems, Inc. 1235 Walt Whitman Road, Melville, NY 11747
(631) 271-0400 FAX (631) 271-0405
A3800
TOUCH CONTROL LAMP DIMMER
These functions may be implemented with very few interface components, as shown in Figure 5. When implemented in this manner, touching of the Touch Plate causes the lamp brightness to change as follows:
1. If the Touch Plate is touched momentarily (42ms to
333ms), the lamp is:
a) turned off if it was on,
b) turned on if it was off.
The brightness resulting is either full brightness or
depending on the circuit type, a previous brightness
stored in the IC memory.
2. If the Touch Plate is touched for a prolonged time
(more than 342ms) the light intensity changes slowly.
As long as the touch is maintained, the change continues; the direction of change reverses whenever the
maximum or minimum brightness is reached.
7231-4-120100-1
V SS(+V)
1
8
TRIG
DOZE
2
7
V DD (-V)
CAP
3
6
EXT
SYNC
4
5
SENS
LS7231-34
DESCRIPTION:
LS7231 through LS7234 are a series of monolithic, MOS
integrated circuits designed for the control of brightness 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 halfcycle, the output can be positioned anywhere between
158˚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 a low level at the SENS input or a high
level at the EXT input.
PIN ASSIGNMENT - TOP VIEW
LSI
FEATURES:
• Phase-lock loop synchronization allows use in Wall
Switch applications.
• Provides brightness control of incandescent lamps
with touch plates or mechanical switches.
• Controls the "duty cycle" from 23% to 88%
(conduction angles for AC half-cycles between 41˚
and 158˚, respectively.)
• Operates at 50Hz/60Hz line frequency.
• Extension input for remote activation.
• Input for slow dimming.
• +12V to +18V DC Power Supply voltage. (VSS - VDD)
• LS7231 to LS7234 (DIP) - See Figure 1
LS7231-S to LS7234-S (SOIC)
December 2000
FIGURE 1
The IC also provides an input for slow dimming. By
applying a slow clock to this input, the lamp can be
dimmed slowly until total turn off occurs. This feature can be useful at bedtime in a child’s room.
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 turns off, this input has no further effect. The lamp can be turned on
again by activating either the SENS input or the EXT input. For the transition from maximum brightness to off, a
total of 83 clock pulses are needed at the DOZE input.
When either the SENS or the EXT input is active, the
DOZE input is disabled. (See Figure 7)
CAP (Pin 3)
The CAP input is for the PLL filter capacitor. A 0.047µF
capacitor should be connected to this input.
The functional differences of different versions of the light dimmer ICs are explained in Table 1 and the TRIG
output conduction angle diagrams in Figure 2.
PART
NUMBER
LS7231
TABLE 1
TOUCH TYPE
SHORT (TS1 Duration)
PRE-TOUCH
Ø
Off
Max
Intermediate
PRE-TOUCH
Ø
Off
Max
Intermediate
N/A
N/A
NO
YES
Off
Max
Intermediate
Starts varying at Min
Starts varying at Max
Starts varying at
Pre-Touch brightness
N/A
N/A
YES
Off
Starts varying at
Memory (Note 2)
Starts varying at Max
Starts varying at
Pre-Touch brightness
NO
Max
Intermediate
Max
Intermediate
LS7233
Off
Max
Intermediate
Max
Off
Off
LS7234
Off
Memory
(Note 1)
Off
Off
Max
Intermediate
POST-TOUCH
Ø
Starts varying at Min
Starts varying at Max
Starts varying at
Pre-Touch brightness
Starts varying at
Memory (Note 2)
Starts varying at Max
Starts varying at
Pre-Touch brightness
Memory
(Note 1)
Off
Off
LS7232
Off
POST-TOUCH
Ø
Max
Off
Off
LONG (TS2 Duration)
DIMMING
DIRECTION
REVERSAL
(Note 3)
Off
Max
Intermediate
N/A
YES
N/A
NO
NOTE 1: "Memory" refers to the conduction angle, Ø which existed prior to the current off-state. First time after power-up,
the Memory value defaults to maximum conduction angle.
NOTE 2: First time after power-up, LONG touch causes intensity to vary starting at minimum conduction angle.
NOTE 3: NO = Dimming direction does not reverse from prior dimming direction.
YES = Dimming direction does reverse from prior dimming direction.
N/A = Does not apply
SYNC (Pin 4)
The AC Line Frequency is applied to this input through an
external RC circuit (See Figure 5). The Phase-Lock Loop
in the IC synchronizes all internal timings to the AC signal
at the SYNC input.
EXT (Pin 6)
The EXT input is functionally identical to the SENS input
except that a high level activates this input. It is recommended that the EXT input be used instead of the
SENS input when long extension wires are employed between the IC and the Sensing Circuitry (See Figure 5 and
Figure 6) because the EXT input is less susceptible to
“Noise”.
TRIG (Pin 8)
The TRIG output is a low level pulse occurring once every
half-cycle of the SYNC input. The conduction angle, Ø, of the
output in relation to the SYNC signal controls the lamp brightness.
In continuous dimming operation (i.e. when the SENS input is
continuously held low) the TRIG conduction angle, Ø, sweeps
up and down between 41˚ and 158˚ continuously. The time vs
Ø curve is not linear (See Figure 2). Between two maxima on
this curve, there are 4 discontinuous points labeled A1, B1,
B2, A2. The discontinuities are as follows:
1. From maximum to A1. In this region, Ø is changed by
equal increments (∆ø) for every 2 SYNC clocks.
2. From A1 to B1. In this region, the increments (∆ø) take
place for every 4 SYNC clocks.
3. From B1 to B2. In this region Ø is held at a constant
level (∆ø = 0).
4. From B2 to A2. Same as 2.
5. From A2 to Max. Same as 1.
VDD (Pin 4)
Supply voltage negative terminal.
The slower rate of change in ø over A1B1B2A2 region is to
accommodate for eye adjustment at lower light intensity.
SENS (Pin 5)
A low level activates this input (See Table 1) which controls the turn-on, turn-off and conduction angle Ø (SeeFigure 3) of the TRIG signal with respect to the SYNC input.
7231-34-033195-2
ABSOLUTE MAXIMUM RATINGS:
PARAMETER
SYMBOL
DC Supply Voltage
VSS
Any Input Voltage
VIN
Operating Temperature
TA
Storage Temperature
TSTG
VALUE
+20
VSS -20 to VSS + 0.5
0 to +80
-65 to +150
UNIT
V
V
˚C
˚C
DC ELECTRICAL CHARACTERISTICS:
(TA = 25˚C, all voltages referenced to VDD)
PARAMETER
Supply Voltage
Supply Current
SYMBOL
VSS
ISS
MIN
+12
–
TYP
–
1.0
MAX
+18
1.4
Input Voltages:
DOZE LO
DOZE HI
SYNC LO
SYNC HI
SENS LO
SENS HI
EXT LO
EXT HI
VIZL
VIZH
VIRL
VIRH
VIOL
VIOH
VIVL
VIVH
Input Current:
SYNC, SENS, EXT HI
SYNC, SENS, EXT LO
DOZE HI
DOZE LO
TRIG HI Voltage
TRIG LO Voltage
TRIG Sink Current
UNIT
V
mA
CONDITION
VSS = +15V,
output off
0
VSS-2
0
VSS-5.5
0
VSS-2
0
VSS-2
–
–
–
–
–
–
–
–
VSS-6
VSS
VSS-9.5
VSS
VSS-8
VSS
VSS-8
VSS
V
V
V
V
V
V
V
V
-
IIH
–
–
110
µA
IIL
IIH
IIL
VOH
VOL
IOS
–
–
–
–
–
25
–
–
–
VSS
VSS-8
–
100
100
100
–
–
–
nA
nA
nA
V
V
mA
With Series 1.5MΩ
Resistor to
115VAC Line
VSS = +15V
VSS = +15V
VOL = VSS-4V
TIMING CHARACTERISTICS (See Figures 2 and 3):
All timings are based on fs = 60Hz, unless otherwise specified. 50Hz timings are 1.2 times 60Hz timings.
PARAMETER
SYMBOL
MIN
TYP
MAX
UNIT
SYNC Frequency
fs
40
70
Hz
SHORT TOUCH
TS1
42
333
ms
(ON/OFF Operation)
LONG TOUCH
TS2
342
infinite
ms
(Dimming Operation)
DOZE Frequency
500
Hz
TRIG Pulse Width
TW
33
µs
TRIG Conduction-Angle
Ø
41
158
degrees
(Note 1)
Ø Period (Max to Max in
7.64
seconds
continuous dimming)
A1B1 = B2A2 duration
934
ms
B1B2 Min. intensity dwell
500
ms
NOTE 1.
In the circuit schematic shown in Figure 5, the SYNC input signal is delayed in phase with respect to the AC Line by
about 7°. This delay reduces the conduction angle, Ø with respect to the AC Line by 7° from the values shown above.
7231-34-041195-3
TS2
TS1
SENS
LS7231
LONG
SHORT
341ms
SHORT
SHORT
LONG
LONG
A0
150°
100°
A2
A1
B2
50°
OFF
SLOPE = SAA
SLOPE = SBA
SBA
A2
B1 B2
SAA
B2
SAA
SBA
LS7232
A0
A0
150°
MEMORY
100°
A1
50°
SBA
MEMORY
A2
SAA
SAA
SAA
OFF
B1
SAA
B2
LS7233
SAA
A0
150°
100°
50°
A2
A1
SAA
B2
SBA
A2
SBA
REVERSE
B2
B1 B2
OFF
SAA
SBA
LS7234
A0
A0
150°
MEMORY
100°
A1
50°
SAA
OFF
SBA
A2
B1 B2
B1
SAA
A1
SBA = 1.4° per four SYNC CYCLES, 15 steps total for A1 to B 1 or B2 to A 2
SAA = 1.4° per two SYNC CYCLES, 68 steps total for A 0 to A1 or A2 to A0
FIGURE 2. TRIG OUTPUT CONDUCTION ANGLE, Ø, VS SENS INPUT
7231-4-032795-4
SBA
SBA
SAA
B1
B2
MEMORY
SYNC
ø
TRIG
TW
TW
FIGURE 3. TRIG OUTPUT CONDUCTION ANGLE, Ø
SYNC
4
BUF
PHASE
LOCK
LOOP
CAP
3
DOZE
2
BUF
EXT
6
BUF
SENS
5
BUF
V SS
1
(+V)
7
(-V)
V DD
Ø
MEMORY
DIGITAL
COMPARATOR
CONTROL
LOGIC
OUTPUT
DRIVER
8 TRIG
Ø
POINTER
FIGURE 4
LS7231-4 BLOCK DIAGRAM
APPLICATION EXAMPLE:
A typical implementation of a lamp dimmer circuit is shown in Fig. 5. Here the brightness of the lamp is set by touching the Touch Plate . The functions of different components are as follows:
• The 15V DC supply for the chip is provided by Z, D1, R1, C2 and C5.
• R2 and C4 generate the filtered signal for the SYNC input for synchronizing the internal PLL with the line
frequency.
• R3 and C7 act as a filter circuit for the electronic extension. If extensions are not used, the EXT input (Pin 6)
should be tied to VDD (Pin 7).
• R4, R5, R6 set up the sensitivity of the SENS input. C6 provides noise filtering.
• C3 is the filter capacitor for the internal PLL.
• R8 provides current limiting and isolation between the chip output and the triac gate.
• C1 and L are RF filter circuits.
In the case of momentary power failure, the circuit state remains unchanged for a period of up to 1 sec. For longer
power interruptions, the output is shut off.
7231-4 040695-5
FIGURE 5. A Typical Lamp Dimmer
P
P
SEE NOTE 2
C7
R8
G
EXTN
R7
MT1
T
MT2
+
Z
-
R3
C5
ELECTRONIC
EXTENSION
(FIG. 6)
SEE NOTE 5
D1
L
115VAC
OR
220VAC
R6
C1
8
C2
TRIG
7
6
R2
V DD
V SS D O Z E CAP SYNC
1
2
3
4
A
SEE NOTE 3
C3
C4
SENS
C6
B
LOAD
TOUCH
PLATE
V DD EXT S E N S
LS7231-4
R1
R5
5
DOZE
CIRCUIT
(FIG. 7)
R4
SEE NOTE 4
DZ
V SS
N O T E S 1) All circuits connected by broken lines are optional.
2) C7 is used only with electronic extension and R7 is used only with mechanical switch.
3) Connection between Pin 1 & Pin 2 should be broken when DOZE circuit is used.
4) Use Connection A when Neutral is not available. Use Connection B when Neutral is available.
5) Connection between Pin 6 & Pin 7 should be broken when EXT is used.
N
C1 = 0.15µF,200V
(1) C2 = 0.33µF,200V
C3 = 0.047µF,25V
C4 = 470pF,25V
C5 = 47µF,25V
C6 = 680pF,25V
C7 = 0.1µF,25V
(2) R1 = 270Ω,1W
R2 = 1.5MΩ,1/4W
R3 = 1.5MΩ,1/4W
115V
R4 = 1MΩ to 5MΩ,1/4W
(Select for sensitivity)
R5, R6 = 2.7MΩ,1/4W
R7 = 150KΩ,1/4W
R8 = 100Ω,1/4W
D1 = IN4148
Z = 15V,1W (Zener)
T = Q4006L4 Triac (Typical)
L = 100µH (RFI Filter)
(1) For Connection A. Use 0.22µF for Connection B.
(2) For Connection A. Use 1/4W for Connection B.
7231-4-041597-6
220V
C1 = 0.15µF, 400V
(3) C2 = 0.22µF, 400V
C3 = 0.047µF, 25V
C4 = 470pF, 25V
C5 = 47µF, 25V
C6 = 680pF,25V
C7 = 0.1µF, 25V
(4) R1 = 1KΩ, 2W
R2 = 1.5MΩ,1/4W
R3 = 1.5MΩ,1/4W
R4 = 1MΩ to 5MΩ,1/4W
(Select for sensitivity)
R5, R6 = 4.7MΩ,1/4W
R7 = 150KΩ,1/4W
R8 = 100Ω,1/4W
D1 = 1N4148
Z = 15V,1W (Zener)
T = Q5004L4 Triac (Typical)
L = 200µH (RFI Filter)
(3) For Connection A. Use 0.1µF for Connection B.
(4) For Connection A. Use 1/4W for Connection B.
TOUCH PLATE
*R
2KΩ ,1/4W
IN914
EXTN
*R
MPS8599
*R = 2M Ω ,1/4W for 115VAC
*R = 3.6M Ω ,1/4W for 220VAC
200K Ω ,1/4W
P
FIGURE 6.
ELECTRONIC EXTENSION
EXTENSIONS:
All switching and dimming functions can also be implemented by utilizing the EXT input. This can be
done by either a mechanical switch 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
half- cycles of the line frequency. (See Figure 5)
3.3M
VSS
3.3M
,1/4W
,1/4W
U1-1
DZ
U1-3
+
10µF
-
SENS
U1-2
DOZE
SWITCH
DZ
U1 = CD4093
VDD
FIGURE 7.
DOZE CIRCUIT
DOZE CIRCUIT:
The DOZE circuit shown in Figure 7 generates a slow clock (0.04Hz) at the DZ terminal. If the Touch Plate
(Figure 5) is not touched, the SENS terminal of the DOZE circuit of Figure 7 sits at a logic high level. A momentary pressing of the DOZE switch sets the SR flip-flop, enabling the oscillator. Every negative transition
of the clock (DZ terminal) causes the light intensity to be reduced by equal increments, until eventually the
light is shut off. The oscillator has no further effect on the dimmer circuit. When the light is turned on again
by touching theTouch Plate, the SR flip-flop is reset and the DZ clock is turned off.
When the DOZE circuit is used, the connection between DOZE input (Pin 2) and VSS (Pin 1) as shown in
Figure 5, should be removed.
.
7231-4-041195-7
FIGURE 8. A SWITCH-OPERATED LAMP DIMMER
AC ON-OFF SWITCH
R3
G
MT1
+
T1
MT2
Z1
C5
PUSHBUTTON
SWITCH
-
D1
L
115VAC
OR (SEE NOTE)
220VAC
C2
C1
8
7
6
5
TRIG V DD EXT S E N S
LS7231-4
R1
R2
V SS D O Z E CAP SYNC
1
2
3
4
C3
C4
R4
OUT
TO
LAMP
NOTE: Operation is independent of Line Plug Polarity
115V
C1 = 0.15µF, 200V
C2 = 0.22µF, 200V
C3 = 0.047µF, 25V
C4 = 470pF, 25V
C5 = 47µF, 25V
R1 = 270Ω, 1/4W
R2 = 1.5MΩ, 1/4W
R3 = 100Ω, 1/4W
R4 = 1MΩ, 1/4W
D1 = IN4148
Z1 = 15V, 1W (Zener)
T1 = Q4008L4 (Typical)
L = 100µH (RFI Filter)
APPLICATIONS:
1. Foot-Switch Dimmer for large floor lamps.
2. Hand-Switch Dimmer for end-table lamps.
7231-4-032995-8
220V
C1 = 0.15µF, 400V
C2 = 0.1µF, 400V
C3 = 0.047µF, 25V
C4 = 470pF, 25V
C5 = 47µF, 25V
R1 = 1KΩ, 1/4W
R2 = 1.5MΩ, 1/4W
R3 = 100Ω, 1/4W
R4 = 1MΩ, 1/4W
D1 = IN4148
Z1 = 15V, 1W (Zener)
T1 = Q5004L4 (Typical)
L = 200µH (RFI Filter)
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.
Similar pages