EK56
4
EK56U Rev M
7. Apply a thin layer of thermal grease on the back of the chosen current limiting sense resistor R2 and insert
the resistor into the PCB. Mount the resistor to the HS28 heat sink using #4 screw and nut hardware (not
supplied). Place the screw into the mounting hole from the narrow-channel side of the heat sink and
place the nut on the screw from the wide-channel side of the heat sink. Do not over tighten the screw.
Finally, solder the resistor terminals to the PCB and
cut off the excess lead length
.
8. Mount the remaining HS28 heat sink similarly to step 6.
9. Repeat step 7 for R1 and the second HS28 heat sink.
10. Mount the electrolytic capacitor at C2 from the “component side” of the PCB. Match the polarity mark-
ings on the capacitor with the polarity markings on the PCB. Use the correct voltage capacitors for the
product you are using: A 100V capacitor for the MSA240KC, or a 450V capacitor for the MSA260KC. Be
sure the capacitors have snapped into the PCB and solder from the “DUT side” of the PCB. Be sure to fill
the holes with solder.
11. Mount the terminal strip to the “component side” of the PCB. Make sure the terminal strip is fully seated
and solder the pins from the “DUT side” of the PCB. Be sure to fill the mounting holes with solder.
12. Mount a BNC connector (not supplied) to the PCB at location 5 (near the banana jacks) if desired. The
body of the BNC connector is tied to SIG GND.
13. Mount other components to complete your application circuit using the pads and holes provided. Refer to
the data sheet for your model and note that:
It is therefore convenient to use 3 resistors of equal value and make up R
RAMP
from two of those
resistors. Note on the PCB locations for R
RAMP1
and R
RAMP2
to do this.
14. From the “DUT side” of the PCB snap the spacer- grommets into the holes at the four corners of the PCB.
Notice that the holes are slightly rectangular and match the spacer-grommet's long and short sides to the
holes in the PCB.
15. Apply a thin, uniform layer of thermal grease to the amplifier; a straight edge may be useful here. Position
the amplifier over the mounting holes in the heatsink. Firmly push the amplifier onto the heatsink while
slightly rotating the amplifier back and forth, ending with the mounting holes of the amplifier over the
mounting holes in the heatsink.
16. Attach the amplifier to the heatsink with 4-40x½’ male-female hex spacers (not supplied). These spacers
serve as alignment pins and aide in the assembly of the PCB to the heatsink. Alternatively, use 4-40x¼’
machine screws to mount the amplifier to the heatsink. Do not over-tighten the spacers or screws as this
provides no thermal benefit and may break the hardware.
17. Place the PCB assembly on the heatsink/amplifier assembly so that the hex spacers come through the
aligning holes near the corners of the amplifier location in the PCB. Carefully lower the PCB assembly until
the pins of the amplifier engage the cage jacks. Alternately, sight through the aligning holes in the PCB
and match-up the PCB to the screws used to mount the amplifier. In either case be sure the pins of the
amplifier are engaged with the cage jacks and then continue pushing the PCB assembly in the area
between the amplifier’s pins until the four spacer grommets at the four corners of the PCB touch the
heatsink. At this point the PCB should not be bowed.
18. Using #8 X 1" sheet metal screws (not provided) mount the PCB to the heat sink at the four spacer-grom-
mets.
19. Hook up power and signals as necessary. The amplifier is now ready for testing.
R
RAMP
2
XR
OSC
=
