
5
Motorola Optoelectronics Device Data
0.315
″
MIN
[8 MM MIN]
Thermal measurements of R
θ
JC
are referenced to the point on
the heat tab indicated with an
‘X’. Measurements should be
taken with device orientated
along its vertical axis.
Use care to maintain the minimum spacings as shown.
Safety and regulatory requirements dictate a minimum
of 8.0 mm between the closest points between input
and output conducting paths, Pins 3 and 7. Also, 0.070
inches distance is required between the two output
Pins, 7 and 9.
Keep pad sizes on Pins 7 and 9 as large as possible
for optimal performance.
0.070
″
MIN
Each device, when installed in the circuit shown
in Figure 14, shall be capable of passing the fol-
lowing conducted noise tests:
IEEE 472 (2.5 KV)
Lamp Dimmer (NEMA Part DC33, 3.4.2.1)
NEMA ICS 2–230.45 Showering Arc
MIL–STD–461A CS01, CS02 and CS06
{
}
JUNCTION
TEMPERATURE OF
MOC2A60 . . .
OUTPUT CHIP
WITH ADDITIONAL HEATSINK
TC
R
θ
JC
R
θ
CA
R
θ
SA
R
θ
CS
R
θ
JC
NO ADDITIONAL HEATSINK
TC
AMBIENT AIR
TEMPERATURE
HEAT FLOW
Z LOAD
0.022
μ
F
10
150V
MOV
AC
SUPPLY
NOISE
SOURCE
2
DEVICE UNDER TEST
3
7
9
Terms in the model signify:
TA = Ambient temperature
TS= Optional additional
TS=
heat sink temperature
TC = Case temperature
TJ = Junction temperature
PD = Power dissipation
Values for thermal resistance components are: R
θ
CA = 36
°
C/W/in maximum
Values for thermal resistance components are:
R
θ
JC = 8.0
°
C/W maximum
The design of any additional heatsink will determine the values of R
θ
SA and R
θ
CS.
TC – TA = PD (R
θ
CA)
TC – TA
= PD (R
θ
JC) + R
θ
SA), where PD = Power Dissipation in Watts.
Figure 15. Approximate Thermal Circuit Model
R
θ
SA = Thermal resistance, heat sink to ambient
R
θ
CA = Thermal resistance, case to ambient
R
θ
CS = Thermal resistance, heat sink to case
R
θ
JC = Thermal resistance, junction to case
IF = RATED IF
TJ
TA
TJ
TA
TS
Figure 13. PC Board Layout Recommendations
Figure 14. Test Circuit for Conducted Noise Tests