MOC3081 Datasheet, PDF (7/11 Pages) Motorola, Inc – 6-Pin DIP Zero-Cross Optoisolators Triac Driver Output

800V
Vdc
PULSE
INPUT
R_TEST
MERCURY
WETTED
RELAY
C_TEST
10 kΩ
D.U.T.
X100
SCOPE
PROBE
Figure 9. Static dv/dt Test Circuit
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.
APPLIED VOLTAGE
WAVEFORM
504 V
V_max = 800 V
0 VOLTS
dv/dt =
0.63 Vmax
tRC
=
504
tRC
tRC
Figure 10. Static dv/dt Test Waveform
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, 15mA for the MOC3081M, 10mA for the MOC3082M,
and 5mA for the MOC3083M. The 39Ω resistor and 0.01µF capacitor are for snubbing of the triac and may or may not
be necessary depending upon the particular triac and load use.
V_CC
R_in
1
6 ^{360 Ω}
HOT
2
MOC3081M
5
MOC3082M
MOC3083M
3
4
330 Ω
FKPF12N80
39*
0.01
240 VAC
LOAD
NEUTRAL
* For highly inductive loads (power factor < 0.5), change this value to 360Ω.
Figure 11. Hot-Line Switching Application Circuit
R1 D1
1
V_CC
6
R_in
2 ^MOC3081M
MOC3082M
5
MOC3083M
3
4
360 Ω
SCR
R2
D2
Figure 12. Inverse-Parallel SCR Driver Circuit
240 VAC
SCR
LOAD
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 330Ω.
Note: This optoisolator should not be used to drive a load directly. It is intended to be a trigger device only.
©2005 Fairchild Semiconductor Corporation
MOC3081M, MOC3082M, MOC3083M Rev. 1.0.3
7
www.fairchildsemi.com