TjDIODE = [Pd] ⋅ θjcDIODE + TC
θjcDIODE = 0.85°C/W
TC = 85° C
TjDIODE = 29.25 ⋅ 0.85° + 85°
TjDIODE = 109.9° C
Maximum hybrid dissipation will be:
PHYBRID = 2[Ps + Pc + Pd]
PHYBRID = 2[125 + 4 + 29.25]
PHYBRID = 316.5 W
MECHANICAL
The ACT5101-1 construction utilizes only the highest quality materials and manufacturing available to
ensure a high reliability, robust power hybrid design. The case is selected for best thermal conductivity,
hermeticity, and voltage/current carrying capability. The case is electrically isolated from the circuit and
can withstand 1500 VAC from pin to case, and input pins to output pins, therefore no insulating pads or
washers are required for mounting.
In order to remove the heat being generated from the ACT5101-1, it must be bolted down to the motor, a
heat sink or the actual system chassis such as a missile structure or aircraft wing rib for example. Thermally
conductive grease or a "Sil-pad" is recommended between the hybrid case baseplate and its mounting
surface to fill in any surface imperfections and improve the heat transfer from case-to-heat sink. It is
important to keep the temperature at this interface no greater than +125 degrees C in order to maintain
safe semi-conductor junction temperatures.
The leads of the ACT5101-1 can be formed upward, away from the baseplate, so that a PC board can be
mounted directly above it. A wiring harness can also be hand-wired and soldered directly to the leads of
the ACT5101-1 if this is preferred.
11
Aeroflex Circuit Technology
SCD5101-1 REV D 5/14/01 Plainview NY (516) 694-6700
AEROFLEX [ AEROFLEX CIRCUIT TECHNOLOGY ]
