Heatsinks for the FMC Fine Delay
This page summarizes the heatsink testing results.
Fine Delay on SVEC (lab test)
Test evironment:*
- crate: 20-slot Wiener VME64x
- crate contents: single SVEC in VME slot 5 with the card under test in FMC slot 2 and FMC TDC in FMC slot 1
- fan speed: 1200 RPM (minimum)
- ambient temperature: 20 deg Celsius
- warm-up time: 8 minutes
Results:*
| Serial No | Configuration | Temperature (degrees Celsius)
|
| CR37 | no heatsink | 59.7 |
| CR09 | small heatsinks on delay and PLL chips | 51.7 |
| CR01 | big heatsink in the rear of the card | 58.6 |
| CR03 | both heatsinks | 52.3 |
Conclusions:*
- big heatsink gives very little temperature drop (1 degC can be
considered measurement error). See the section with thermal camera
measurements for details.
- small heatsinks glued on the chips give improvement of 8 degrees C.
Detailed temperature measurements on different platforms:
Note:* All temperatures in degrees Celsius.
Test environment
- VME: Wiener and Elma crates, with up to 7 SVECs (14 Fine Delays)
installed in subsequent slots. Whenever possible, different
combinations
of VME slots and fan speeds were used. Ambient temp 26-28.
- PCI Express: Kontron industrial PC, with 5 SPECs and 5 Fine Delays.
Ambient temp 19-20.
- Temperatures were logged over time to make sure they have settled up
before taking measurements. The first stable sample (with less than 1
degree temperature change over 1 minute) was used for the statistics.
Data:
Wiener 21-slot VME64x crate, fans at 1200 rpm (minimum speed):*
Slots 4-10:
| Slot/FMC | 4/1 | 4/2 | 5/1 | 5/2 | 6/1 | 6/2 | 7/1 | 7/2 | 8/1 |
8/2 | 9/1 | 9/2 | 10/1 | 10/2 |
| Temperature | 65.69 | 71.38 | 56.88 | 66.25 | 50.69 | 63.88 |
51.19 | 63.62 | 58.62 | 73.25 | 61.44 | 71.00 | 50.12 | 59.62 |
Slots 9-15:
| Slot/FMC | 9/1 | 9/2 | 10/1 | 10/2 | 11/1 | 11/2 | 12/1 | 12/2 |
13/1 | 13/2 | 14/1 | 14/2 | 15/1 | 15/2 |
| Temperature | 62.00 | 71.12 | 60.19 | 74.31 | 61.25 | 73.75 |
51.94 | 65.12 | 48.75 | 60.88 | 51.31 | 62.75 | 52.12 | 64.06 |
Wiener 21-slot VME64x crate, fans at 3600 rpm (maximum speed):*
Slots 4-10:
| Slot/FMC | 4/1 | 4/2 | 5/1 | 5/2 | 6/1 | 6/2 | 7/1 | 7/2 | 8/1 |
8/2 | 9/1 | 9/2 | 10/1 | 10/2 |
| Temperature | 52.75 | 57.06 | 45.31 | 51.56 | 39.31 | 48.31 |
40.38 | 48.31 | 47.38 | 58.81 | 49.94 | 55.00 | 40.75 | 46.12 |
Slots 9-15:
| Slot/FMC | 9/1 | 9/2 | 10/1 | 10/2 | 11/1 | 11/2 | 12/1 | 12/2 |
13/1 | 13/2 | 14/1 | 14/2 | 15/1 | 15/2 |
| Temperature | 49.44 | 55.00 | 48.81 | 56.50 | 49.88 | 55.00 |
41.44 | 50.88 | 40.69 | 50.12 | 41.31 | 48.12 | 42.75 | 49.00 |
Conclusions*
- Cards in the middle slots (8-10) are the worst (25 degC difference
over slots 7 and 12). Uneven air flow in the crate?
- FMC1 is approximately 8-10 degrees cooler than FMC2.