LSI LS7340 Auto shut-off ac power switch with programmable timer Datasheet

LSI/CSI
UL
LS7339-7340
®
LSI Computer Systems, Inc. 1235 Walt Whitman Road, Melville, NY 11747
(631) 271-0400 FAX (631) 271-0405
A3800
AUTO SHUT-OFF AC POWER SWITCH
WITH PROGRAMMABLE TIMER
DESCRIPTION:
The LS7339 and LS7340 are MOS integrated circuits designed to turn
a triac On and Off in a Power Switch for AC loads. Activation of the
ON input will always turn the triac On and start a Timer. The triac remains On for the duration of the Timer which is controlled by an external R-C connected to the OSCILLATOR input. Activation of the
OFF input will always turn the triac Off. The two ICs differ only in the
width of the TRIG pulse used to trigger the triac.
(See I/O Description, Pin 4.)
In a typical application (Figure 5), the output of the LS7339 drives the
gate of a triac in series with the load. Because the LS7339 is accurately synchronized to the line frequency with a phase-lock loop, the
power delivered by the triac to the load is pure AC, allowing use with
inductive loads such as motors and transformers.
There are two states through which the LS7339 can be stepped. The
states and their corresponding operating modes, phase angles, and
delivered power levels are shown in Table 1.
TABLE 1
(See Figures 2 and 3)
STATE 0
STATE 1
OPERATING MODE
OFF
Timed-On
PHASE ANGLE, ø
No Output
159˚
% LOAD POWER (1)
0
99
(1) The percentage of full power delivered to a resistive load
by the triac switch.
OPERATING DESCRIPTION:
Upon power up, internal power-on-reset starts the LS7339 in STATE 0.
When the ON input transitions to logic 0, the circuit steps to STATE 1.
When the OFF input transitions to logic 0, the circuit steps to STATE 0.
When implemented as shown in the application example (Figure 5),
this is accomplished by the momentary switching of the appropriate input to VDD through S1. STATE 1 is a quasi-stable state.
7339-012703-1
ON
1
OFF
2
V DD (-V)
TRIG
3
LS7339/7340
APPLICATIONS:
• AUTO SHUT-OFF TIMER for appliances such as coffee pots,
curling irons, hair curlers, electric blankets, hand dryers.
• TIMED-ON WALL SWITCH for incandescent lighting and
heat lamps.
PIN ASSIGNMENT - TOP VIEW
LSI
FEATURES:
• Phase-Lock Loop Synchronization allows use in
Wall Switch Applications.
• PLL accuracy delivers Pure AC Power.
• Timer programmable with external R-C.
• ON input switches AC Power On and starts Timer.
• OFF input switches AC Power Off.
• 50/60Hz Line Frequency.
• +12V to +18V Operation (VSS - VDD).
• LS7339, LS7340 (DIP); LS7339-S, LS7340-S - See Figure 1
January 2003
4
8
SYNC
7
CAP
6
OSC
5
V SS (+V)
FIGURE 1
If left in STATE 1, after a time-out period determined by the
frequency set at the OSC input (See I/O Description, Pin 6),
the circuit automatically steps to STATE 0. If the ON input transitions to logic 0 before completion of the time-out period in
STATE 1, the Timer is restarted, beginning a new time-out
INPUT/OUTPUT DESCRIPTION:
ON (Pin 1) - See NOTE 1
A logic 0 applied to this input for a minimum of three SYNC cycles, TS1 (50ms for 60Hz, 60ms for 50Hz), turns TRIG On and
starts a Timer. Upon completion of the Time-out, TD1, TRIG
turns Off. While the Time-out is in progress a new transition to
logic 0 at this input for a minimum of three SYNC Cycles, TS1,
restarts the Timer. This input is designed for Touch or Switch
control. (See Figure 5.)
OFF (Pin 2) - See NOTE 2
A logic 0 applied to this input for a minimum of three SYNC cycles, TS1, turns TRIG Off. This input is designed for Switch control only. (See Figure 5.)
VDD (Pin 3)
Supply voltage negative terminal.
TRIG (Pin 4)
TRIG is a negative going pulse occurring once every half cycle
of the SYNC input. Pulse width is 1ms (LS7339) or 33µs
(LS7340). The LS7339 wide pulse width may be required for inductive loads. The LS7340 narrow pulse width allows use of a
smaller value of C2 power supply capacitor. (See Figure 5.)
VSS (Pin 5)
Supply voltage positive terminal.
OSC (Pin 6)
An R-C network connected to this input controls the frequency
of oscillation which determines the Time-out, TD1, in State 1. TD1
is approximately 255RC. The Oscillator is active only in State 1.
Chip to chip Oscillation Tolerance is ±10% for fixed value of RC.
Tie Pin 6 to VSS if a Time-out is not desired. (See Figure 5.)
CAP (Pin 7)
The CAP input is for external component connection for the PLL filter capacitor. (See Figure 5.)
SYNC (Pin 8)
The AC Line Frequency (50/60Hz) is applied to this input. The
Phase-Lock Loop synchronizes all internal timings to the AC signal
at the SYNC input. (See Figure 5.)
SYNC
ø
NOTE 1: ON will function as described if OFF is at logic 1.
If OFF is held at logic 0, the transitions at ON will
not cause the output to turn On.
TRIG
NOTE 2: OFF will function as described if ON is at logic 1.
If ON is held at logic 0, the transitions at OFF
will not cause the the output to turn Off.
Tw
Tw
FIGURE 2. OUTPUT CONDUCTION ANGLE, Ø
FIGURE 3. OUTPUT PHASE ANGLE Ø VS ON AND OFF
ON
TS1
TS1
TS1
TS1
OFF
TD1
TD1
<TD1
TS1
TD1 RESTART
159˚/STATE 1
Ø
OFF
159˚/STATE 1
159˚/STATE 1
OFF
OFF/STATE 0
OFF
FIGURE 4. LS7339/7340 BLOCK DIAGRAM
SYNC
8
CAP
7
BUF
PHASELOCK
LOOP
DIGITAL
COMPARATOR
ON
1
BUF
OFF
2
BUF
OSC
6
V SS
5
(+V)
V DD
3
(-V)
7339-012703-2
SYNC
PHASE-ANGLE
POINTER
CONTROL
LOGIC
DRIVER
4 TRIG
ø DECODE
OSC/TIMER
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.
ABSOLUTE MAXIMUM RATINGS:
PARAMETER
DC supply voltage
Any input voltage
Operating temperature
Storage temperature
SYMBOL
VSS - VDD
VIN
TA
TSTG
VALUE
+20
VSS - 20 to VSS + 0.5
0 to +85
-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
1.6
MAX
+18
2.2
UNIT
V
mA
Input Voltages
SYNC Lo
SYNC Hi
ON Lo
ON Hi
OFF Lo
OFF Hi
VIRL
VIRH
VIOL
VIOH
VIVL
VIVH
0
VSS - 5.5
0
VSS - 2
0
VSS - 2
-
VSS - 9.5
VS S
VSS - 8
VSS
VSS - 8
VSS
V
V
V
V
V
V
-
IIH
-
-
110
uA
With Series 1.5MΩ
Resistor to 115VAC
IIL
-
-
100
nA
-
VOH
VOL
IOS
25
VSS
VSS - 8
-
-
V
V
mA
VSS = +15V
VSS = +15V,
VOL = VSS - 4V
Input Current
SYNC, ON &
OFF Hi
SYNC, ON &
OFF Lo
TRIG Hi Voltage
TRIG Lo Voltage
TRIG Sink Current
CONDITIONS
VSS = +15V,
Output off
TRANSIENT CHARACTERISTICS (See Fig. 2 and 3)
(All timings are based on Fs = 60Hz, unless otherwise specified.)
PARAMETER
SYNC Frequency
ON/OFF Sense Time
SYMBOL
Fs
Ts1
MIN
40
50
TYP
-
MAX
70
Infinite
UNIT
Hz
ms
TRIG Pulse Width
(LS7339)
(LS7340)
Tw
Tw
-
1.0
33
-
ms
µs
STATE 1 Time-out
TD1
-
255RC
-
s
TABLE 2. COMPONENT FUNCTIONAL DESCRIPTION FOR FIGURE 5
COMPONENTS
FUNCTIONAL DESCRIPTION
Z1, D1, R1, C2, C3
DC Power Supply.
R2, C4
Current limit and filter AC for SYNC input.
C1, L1
RFI filtering for AC Mains.
C5
PLL filter capacitor.
R5
Current limiting and isolation between the IC output and Triac Gate.
R6, R7, C6
Oscillator R-C network. Potentiometer R6 required only if providing user adjustment of Time-out, TD1.
R3, R4
Pullup resistors to establish normally inactive condition of ON and OFF inputs.
S1
Momentary Double Throw Switch used to activate appropriate input.
7339-012703-3
FIGURE 5. A TYPICAL AUTO SHUT-OFF AC POWER SWITCH
P
R5
G
SEE
NOTE 2
R8
MT1
R3
T1
C7
MT2
+
Z1
-
ON
S1
C3
OFF
D1
AC
MAIN
S
C1
R2
R4
L1
4
C2
3
2
TRIG V DD
R6
1
OFF
ON
LS7339
R1
V SS
OSC
5
A
B
SEE
NOTE 1
CAP SYNC
6
7
8
R7
LOAD
C5
-
C4
+
C6
N
NOTES:
1. Use Connection A when Neutral is not available.
Use Connection B when Neutral is available.
2. Snubber Network C7, R8 may be required for
some inductive loads.
3. See Table 2 for Component Functional Description.
FIGURE 6. PRODUCING VERY LONG TIME-OUTS BY PULSE MODULATING THE OSCILLATOR
-V
4
R2
TRIG
115VAC
220VAC
D1
Oscillator
Components
R1
Waveform A
(1)(3) R1
(2)(4) R1
R2
R3
R4
R5
R6
R7
R8
C1
(1) C2
(2) C2
(3) C2
(4) C2
(1)(2) C3
(3)(4) C3
C4
C5
C6
C7
Z1
D1
L1
(7)T1
150Ω, 1W
360Ω, 2W
82Ω
82Ω
1.5MΩ
1.5MΩ
100kΩ
100kΩ
100kΩ
100kΩ
100Ω
100Ω
(5)(6)
(5)(6)
(5)(6)
(5)(6)
1.8kΩ, 1W
1.8kΩ, 2W
0.15µF, 200V 0.15µF, 400V
1.0µF, 200V 0.47µF, 400V
0.47µF, 200V 0.22µF, 400V
0.33µF, 200V 0.22µF, 400V
0.22µF, 200V 0.1µF, 400V
100µF
100µF
47µF
47µF
470pF
470pF
0.047µF
0.047µF
(6)
(6)
0.1µF, 200V 0.1µF, 400V
15V, 1/2W
15V, 1/2W
1N4148
1N4148
100µH
200µH
Q4008L4
Q5004L4
(1) LS7339, Connection A (7) Typical
(2) LS7339, Connection B
(3) LS7340, Connection A
(4) LS7340, Connection B
(5) 100kΩ ≤ (R6 + R7) ≤10MΩ
(6) (R6 + R7)C6 ≥ 5ms
All Resistors 1/4W, all Capacitors 25V
7339-012703-4
D2
R3
2
+
1
V DD OFF
+V
C2
-
3
ON
LS7339
V SS
OSC CAP SYNC
5
6
7
8
CD4093
C1 = 0.1µF
-V
Waveform B (Pulse Modulator)
T1
T1
Waveform A
T2
T1 ≈ R1 C1
Period = T1 + T2
T2 ≈ (R1 + R2)C1
Pulse Duty Cycle = T1/Period
Inverse of Pulse Duty Cycle = Period/T1 = 1 +T2/T1 = 2 + R2/R1
Waveform B
DESCRIPTION:
The Oscillator resistor is normally returned to the negative terminal of the DC Supply.
If this resistor is returned to a negative-going pulse instaed, the Oscillator R-C effectively
becomes multiplied by the inverse of the Pulse Duty Cycle because the Oscillator R-C can
chamge only while the pulse is present. (Pulse Modulation)
In Figure 6, The Oscillator R is R3, the Oscillator C is C2 and the Pulse Modulator is
Waveform B through isolation diode D2. The Multiplier, M = 2 + R2/R1 (the inverse of
the Pulse Duty Cycle).
EXAMPLE:
R3 = 5.1MΩ, C2 = 1.0uF, Pulse Modulator = Waveform B
and desired TD1 = 8 hours = 28,800 seconds.
Since TD1 = 255 x M x R3 x C2, M calculates to be 22 for the selected
Oscillator Components. With M = 22, R2/R1 = 20. If R2 = 3MΩ, R1 = 150kΩ
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