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. All crates used a MEN A20
controller. 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.
- Unused slots were covered to ensure maximum airflow through the FMCs.
Data (without heatsinks):
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 |
Elma 18-slot VME64x crate, default fan configuration:*
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 | 57.44 | 62.56 | 49.75 | 59.06 | 44.50 | 53.88 |
46.00 | 56.38 | 62.00 | 70.94 | 66.44 | 73.69 | 46.69 | 56.31 |
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 | 15/2 |
| Temperature | 66.00 | 72.06 | 66.88 | 73.56 | 57.38 | 65.44 |
46.94 | 59.88 | 45.31 | 56.31 | 50.56 | 60.06 | 59.31 |
Elma 6-slot VME64x crate, default fan configuration:*
| Slot/FMC | 2/1 | 2/2 | 3/1 | 3/2 | 4/1 | 4/2 | 5/1 | 5/2 | 6/1 |
6/2 |
| Temperature | 77.69 | 72.38 | 77.31 | 69.75 | 66.88 | 60.12 |
82.06 | 74.31 | 90.00 | 83.19 |
Kontron KISS 6U industrial PC:*
Slot | 1 | 2 | 3 | 7 | 8 |
Temperature | 89.25 | 92.56 | 98.75 | 88.56 | 79.50 |
Data (with heatsinks)
Kontron KISS 6U industrial PC*
Slot | 1 | 2 | 3 | 7 | 8 |
Temperature | 88.19 | 81.94 | 89.12 | 83.0 | 71.75 |
Summary
Platform | Min temp | Max temp | Mean temp | Max-min | Ambient | Mean-ambient |
Wiener (1200 rpm) | 48.7 | 74.3 | 61.5 | 25.6 | 28 | 33.5 |
Wiener (3600 rpm) | 39.3 | 58.8 | 48.5 | 19.5 | 28 | 20.5 |
Elma 18-slot | 44.5 | 73.7 | 58.7 | 29.2 | 28 | 30.7 |
Elma 6-slot | 60.1 | 90.0 | 75.3 | 29.9 | 28 | 47.3 |
Kontron | 79.5 | 98.8 | 89.2 | 89.7 | 20 | 69.7 |
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. FMC1 is closer to the fans and obstructs air flow to FMC2.
- Large temperature spans in VME crates suggest uneven air flow between different slots.
- Keeping the fans speed at a maximum (Wiener) results with reasonable
cooling (worst temperature: 59).
- On Elma 6U and Kontron PC platforms, the temperatures are
unacceptable and exceed the components rating (-40 ... +85). Heatsink is
needed.
Thermal imaging
tbc
h2. Thermal camera measurements
Replacing the LVPECL delay lines with LVDS counterparts
We tried replacing the SY89295 chips (and their LVPECL terminations)
with an LVDS version: ICS854S296I-33. Temperature test
(identical conditions) performed on a SVEC showed 5 degrees less on the
modified card:
- new delay line 51.31 Celsius
- old delay line 56.38 Celsius