C1 = 0.15µF,200V

R4 = 1M

Ω to 5MΩ,1/4W

C2 = 0.33µF,200V

(Select for sensitivity)

C3 = 0.047µF,25V

R5, R6 = 2.7M

Ω,1/4W

C4 = 470pF,25V

R7 = 150K

Ω,1/4W

C5 = 47µF,25V

R8 = 100

Ω,1/4W

C6 = 680pF,25V

D1 = IN4148

C7 = 0.1µF,25V

Z = 15V,1W (Zener)

R1 = 270

Ω,1W

T = Q4006L4 Triac (Typical)

R2 = 1.5M

Ω,1/4W

L = 100µH (RFI Filter)

R3 = 1.5M

Ω,1/4W

(1) For Connection A. Use 0.22µF for Connection B.

(2) For Connection A, Modes 1 and 2. Use 1/4W for Mode 0

and Connection B, all Modes.

C1 = 0.15µF,400V

R4 = 1M

Ω to 5MΩ,1/4W

C2 = 0.22µF,400V

(Select for sensitivity)

C3 = 0.047µF,25V

R5, R6 = 4.7M

Ω,1/4W

C4 = 470pF,25V

R7 = 150K

Ω,1/4W

C5 = 47µF,25V

R8 = 100

Ω,1/4W

C6 = 680pF,25V

D1 = 1N4148

C7 = 0.1µF,25V

Z = 15V,1W (Zener)

R1 = 1K

Ω, 2W

T = Q5004L4 Triac (Typical)

R2 = 1.5M

Ω,1/4W

L = 200µH (RFI Filter)

R3 = 1.5M

Ω,1/4W

(3) For Connection A. Use 0.1µF for Connection B.

(4) For Connection A, Modes 1 and 2. Use 1/4W for Mode 0

and Connection B, all Modes.

NOTES:

P

115VAC

OR

220VAC

N

LOAD

C1

T

L

C2

R1

R2

A

B

R8

R3

C5

D1

1

2

3

4

8

7

6

5

R4

C3

C4

TRIG VDD EXT SENS

VSS MODE CAP SYNC

+

SEE NOTE 3

LS7237

R6

R5

FIGURE 5. A Typical Lamp Dimmer

G

Z

-

ELECTRONIC

EXTENSION

(FIG. 6)

EXTN

P

C7

SEE NOTE 4

SEE NOTE 2

R7

C6

TOUCH

PLATE

MT2

MT1

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) Use Connection A when Neutral is not available. Use Connection B when Neutral is available.

4) Connection between Pin 6 and Pin 7 should be broken when EXT is used.

(1)

115V

220V

7237-041597-4

APPLICATION EXAMPLES:

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, C5.

• R2 and C4 generate the filtered signal for the SYNC input for syn-

chronizing the internal PLL with the line frequency.

• R3 and C7 act as filter circuit for the electronic extension. If exten-

(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 un-

changed for a period up to 1 sec. For longer power interruptions, the

output is shut off.

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 lev-

el is generated at the EXT input of the IC for both half-cycles of

the line frequency. (See Figure 5)

EXTN

2K

Ω ,1/4W

IN914

TOUCH PLATE

*R

200K

Ω ,1/4W

MPS8599

FIGURE 6. ELECTRONIC EXTENSION

P

*R

*R

*R

(2)

(3)

(4)