Data Sheet
©2005 Fairchild Semiconductor Corporation www.fairchildsemi.com
MOC3081M, MOC3082M, MOC3083M Rev. 1.5 7
MOC3081M, MOC3082M, MOC3083M — 6-Pin DIP Zero-Cross Triac Driver Optocoupler (800 Volt Peak)
Typical circuit for use when hot line switching is required. In this circuit the “hot” side of the line is switched and the load
connected to the cold or neutral side. The load may be connected to either the neutral or hot line.
R
in
is calculated so that I
F
is equal to the rated I
FT
of the part, 15 mA for the MOC3081M, 10 mA for the MOC3082M,
and 5 mA for the MOC3083M. The 39 Ω resistor and 0.01 μF capacitor are for snubbing of the triac and may or may
not be necessary depending upon the particular triac and load use.
Suggested method of firing two, back-to-back SCR’s with a Fairchild triac driver. Diodes can be 1N4001; resistors,
R1 and R2, are optional 330 Ω.
Note: This optoisolator should not be used to drive a load directly. It is intended to be a trigger device only.
1. The mercury wetted relay provides a high
speed repeated pulse to the D.U.T.
2. 100x scope probes are used, to allow high
speeds and voltages.
3. The worst-case condition for static dv/dt is
established by triggering the D.U.T. with a
normal LED input current, then removing the
current. The variable R
TEST
allows the dv/dt to
be gradually increased until the D.U.T.
continues to trigger in response to the applied
voltage pulse, even after the LED current has
been removed. The dv/dt is then decreased
until the D.U.T. stops triggering. τ
RC
is
measured at this point and recorded.
Figure 11. Static dv/dt Test Circuit
Vdc
800V
10 kΩ
C
TEST
X100
SCOPE
PROBE
PULSE
INPUT
MERCURY
WETTED
RELAY
R
TEST
D.U.T.D.U.T.
Figure 12. Static dv/dt Test Waveform
504 V
0 VOLTS
APPLIED VOLTAGE
WAVEFORM
V
max
= 800 V
dv/dt =
0.63 V
max
=
504
t
RC
t
RC
t
RC
Figure 13. Hot-Line Switching Application Circuit
0.01
V
CC
R
in
1
2
3
6
5
4
240 VAC
HOT
FKPF12N80
NEUTRAL
360 Ω
* For highly inductive loads (power factor < 0.5), change this value to 360Ω.
330 Ω
MOC3081M
MOC3082M
MOC3083M
39*
LOAD
Figure 14. Inverse-Parallel SCR Driver Circuit
V
CC
R
in
1
2
3
6
5
4
240 VAC
SCR
360 Ω
R1 D1
SCR
MOC3081M
MOC3082M
MOC3083M
R2 D2
LOAD