6U - SEF-HP - Sealed with Extended Fins + 18/20 Heat Pipes

SEALED COTS ATR - In 5, 7 & 12 slot versions. Certified per MIL-461E & MIL-810F for immediate deployment. Applications up to 300 watts. Configure Now

6U - SEF-HP - Sealed with Extended Fins + 18 Heat Pipes

Custom COTS - Customer configurable & loaded with options: Extended bottom covers, front panel connectors, logos & silk screening, etc. Configure Now

6U - SEF-HP - Sealed with Extended Fins + 20 Heat Pipes

This extreme free-air convection ATR is silent with no external fans making it ideal for submarines and for use in close proximity to operators. Configure Now

6U SEF-HP Description

Sealed, 0.8" pitch, dry-air 6U chassis that incorporates extended cooling fins, 18/20 super conducting heat pipes & air re-circulation fans inside. This Zero maintenance ATR is ideal for medium wattage applications where ambient air is laden with hostile or harmful contaminants.


Heat generated within the enclosure is dissipated by a combination of conduction, radiation and free-air convection through the chassis metalwork & double wall extended fins to the ambient environment. 18/20 integrated heat pipes provide fast passage for heat to exit the internal card-cage. Internal air recirculation fans ensure constant airflow across modules.


The 6U SEF-HP chassis is available in 5, 7, & 12 slot versions ( ½ ATR, ¾ ATR, 1 ATR), supporting VME, cPCI, VPX, VPX-VME & cPCI-VME hybrid backplanes. A total PSU power of up to 1050 watts may be installed. Custom modifications can be designed upon request.

CM-ATR-35/SEF-18HP Layout

Internal layout is divided into 3 independent metallic partitions. I/O section at the front, card-cage in the middle & PSU section at the rear. This improves EMI/EMC performance & reduces PSU noise on system electronics.

Attention to I/O flexibility and easy board integration; allowing the intermixing of wedgelock IEEE P1101.2 conduction cooled boards, IEC-297 air cooled modules, Compact PCI 1101.1/IEC/118/ CD and VPX VITA 46.0/.1/.10/.3/.4/.7 air cooled boards.

6U SEF-HP Performance



Slots / Pitch:5 | 7 | 12   0.8"

Sealed (Dry Air):

≤ 300W

The 6U SEF-HP chassis is suitable for medium wattage sealed applications that demand high passive cooling capability. This silent, fanless model is competitive vs forced air ATRs & ideal for submarine, proximity to operator, deploy & forget applications.

SEF-HP - Chassis Global Thermal Resistance (CGTR) coefficient:
ΔT/W = 0.16°C (½ ATR) | 0.13°C (¾ ATR) | 0.10°C (1 ATR) .

SEF-HP - Chassis Payload Thermal Resistance (CPTR) coefficient:
ΔT/W = 0.165°C (½ ATR) | 0.135°C (¾ ATR) | 0.105°C (1 ATR) .

For reliable operation it is recommended the maximum Payload Power not be exceeded. Subject to operating conditions. All CM 6U ATR chassis are delivered tested, qualified and certified per Military Standards MIL-STD-461E & MIL-STD-810F.

6U SEF-HP Backplanes

CM 6U SEF-HP military backplanes are available in VPX, VMEbus, cPCI, or combinations of VPX-VME64 or cPCI-VME64 hybrids, providing standard bus slot and signal daisy-chain functionalities. Designed to improve card-cage mechanical performance with 0.8 inch pitch slots & implement many features.

CM ATR SEF-HP - 6U VME | cPCI Backpanes

All 6U backplanes install specific TTL logic circuitry for driving up to 8 front panel user LED indicators. Units fitted with a Temperature Supervisory Unit will also drive an additional panel LED TEMP (over/under temperature indicator).

  • VME64x backplanes conduction-cooled IEEE-1101.2 & air-cooled IEC-297/IEEE.1101.1 modules.
  • Compact PCI backplanes according to IEC 1076 / PCI 1101.10/IEC 48D/118/CD standards.
  • VPX backplanes conform to VITA 46.0/.1/.10/.3/.4/.7.
  • VPX-VME64x Hybrid feature mesh-fabric slots that support both VITA46 (VPX) & legacy VME64x slots.

All SEF-HP backplanes integrate a Temperature Supervisory Unit (TSU) with panel LED (over/under temperature) that controls Power Supply & Fan operation. Remote optoisolated control switches for ‘Battle-short’ & chassis PSU ‘on/standby’ are fitted as standard.

CM ATR SEF-HP - 6U VPX | VPX-VME Backpanes

CM 6U military backplanes allow unlimited pin I/O wiring capability. Flexible top & bottom wiring integration is facilitated by a standard 25mm bottom cavity clearance to avoid requiring a custom backplane.

Final slots in 12 & 7 slot chassis allow for bus functionality & contain power/control provisions to accept a eurocard-size metallically caged Redundant PSU. A single slot RPSU up to 575W operates in parallel with main PSU on a load-sharing basis to minimize component stress.

Custom backplanes maybe designed upon customer request.

CM backplanes support one or two 100W power sockets for optional micro-size DC/DC military converters with user defined output voltage. The converters are useful for increasing the +5VDC or +3.3VDC power lines or for generating isolated positive, negative or bipolar auxiliary DC voltages.

CM ATR SEF-HP - 6U cPCI-VME backplanes

Class 1 military power input connectors offer reliable shock & vibration interconnectivity between chassis internal modules and allows high DC current rates with low voltage drops & minimum contact heating.

6U backplanes are supplied with military conformal coating. Printed circuits boards are partially coated per MIL-I-4658C in areas in which do no affect VPX, VME, cPCI, or I/O connectors.

All 6U models integrate similar backplane electronics for easy switch-overs, retrofits or replacement parts.
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6U SEF-HP Power Supplies

6U SEF-HP chassis PSUs support a wide variety of AC/DC input voltages (MIL-STD-704 & MIL-STD-1275) and customer defined DC power output combinations up to 1050 Watts. Available in different versions to suit input voltage requirments.


All PSU models are fitted with Power Fail Monitor, remote voltage sensing, output voltage trim-up, time-delayed protection fuses, rear fan fuse and DC/DC converter remote shutdown.

To comply with MIL-STD-461E, a high capacity integrated EMI/EMC input voltage filter is fitted as standard on all 6U models. PSUs are custom made to match the enclosure mechanics.

200VAC 3-Phase PSU versions incorporate AC/DC rectifier stage prior to the VICOR FIAM front-end modules.

DC PSUs are equipped with a VICOR military Filter and Attenuator Module (FIAM). This front-end device is fitted prior to the DC/DC converters to provide EMI filtering, inrush current limiting and transient protection.


Front-end FIAM modules are protected against DC reverse polarity. An optional reverse polarity diode may be fitted in series with power connector input pin IN (+).

Single-phase AC PSUs are fitted with a VICOR military Filter and Autoranging Rectifier Module (FARM) to provided EMI filtering, autoranging line rectification and inrush current limiting to meet MIL-STD-461E category A1b specifications for Electromagnetic Compatibility.

6U SEF-HP PSUs incorporate isolated DC/DC converters & oversized hold-up capacitors to ensure proper operation during short power line failures. Outputs are protected against short-circuit, thermal-shutdown etc.


The PSU in SEF-HP models is attached to the chassis rear panel, providing thermal conduction to the chassis frame & extended double finned air tunnels.

The rear PSU panel on SEF-HP models incorporates 6 heat pipes to increase DC/DC converter heat removal and dissipation to the external environment.

Internal air recirculation dissipates heat generated via convection cooling that inturn is conducted through all chassis panels.

6U ATR SEF-HP Features

6U SEF-HP No Fans
Fully Sealed Chassis
6U SEF-HP Extended Fin chassis + Heat Pipes are fully sealed with no exterior exhaust fans, requiring Zero maintence & replacement of parts.
6U SEF-HP LED Indicators
LED Front Panel Indicators
Up to 8 front panel LED indicators for chassis monitoring; power on/off status, system board failure, input voltage, temp., etc.
6U SEF-HP Front Panel
Front Panel
Custom layout with client logo, connectors & silk-screening or a general purpose panel with MIL-C-38999 connectors is supplied.
6U SEF-HP Panel Covers
Top/Bottom Covers
Removable Extended Fin Top Cover fitted as standard for superior cooling. A low profile cover is available but with reduced dissipation capacity.
6U SEF-HP Chassis Metalwork
Chassis Metalwork
Precision machined aeronautical aluminum with MIL-DTL-5541F chromate coating. All panels & joints incorporate EMI gaskets.
6U SEF-HP Mounting Tray
Mounting Tray
Low profile with quick release system offers easy insertion/removal capability, weight optimized with minimized dimensions.
EMI/EMC Filter
High capacity integrated EMI/EMC input voltage filter is fitted as standard on all 6U models to comply with MIL-STD-461E.
6U Internal Air Recirculation
Air Recirculation
All 6U chassis incorporate a low profile internal fan pack to recirculate air, improving card-cage, PSU & module heat dissipation.
6U SEF-HP with Extended Fins + 18/20 Integrated Heat Pipes
Sealed Extended Fins + 18/20 Heat Pipes
Fitted with extended double finned side walls and extended fin top cover + 18/20 integrated card-cage heat pipes with exterior airflow tunnels.


  • Contaminant-free enclosure
  • VPX, VME64, cPCI & Hybrid ready (0.8" Pitch)
  • Accepts Conduction & Air-cooled 6U Modules
  • Flexible Top & Bottom I/O wiring
  • In-line EMI/EMC MIL-STD-461F Filter
  • Up to 300W* Total Payload Power (30ºC Delta-T)
  • 18 integrated heat pipes (Ø 8mm)
  • Active Temperature Supervisory Unit (TSU)
  • Extended Fins for increased cooling
  • >10ºC less payload ΔT with respect to S series
  • Dramatically increases payload MTBF by 2x*
  • Maintenance free operation
  • Front panel user indicators
  • Stand alone low weight ATR
  • Internal card-cage airflow recirculation
  • Independent Fan & Power Supply input voltage
  • Military Operating Temperature (-40°C | +85°C)
  • Silent, no noise per Grade A12, MIL-STD-740-1 / MIL-STD-1474 (54dB A-weighted)
  • Customizable to specific requirements
  • Low Profile Mounting Tray with quick release
  • Manufactured with US MIL components
* Subject to operating conditions

6U ATR SEF-HP Specifications

WIDTH 155 mm 195 mm 296 mm
HEIGHT 246 mm 246 mm 246 mm
DEPTH 405 mm 405 mm 405 mm
WEIGHT 6.3 Kg 7.7 Kg 11.2 Kg
CGTR COEFF ΔT/W = 0.16°C ΔT/W = 0.13°C ΔT/W = 0.10°C
HEAT PIPES 18 Heat Pipes Integrated - ⌀ 8mm 18 Heat Pipes Integrated - ⌀ 8mm 20 Heat Pipes Integrated - ⌀ 8mm
CPTR COEFF ΔT/W = 0.165°C ΔT/W = 0.135°C ΔT/W = 0.105°C
SLOTS 5 712
PSU MAX POWER 575 Watts (28 VDC 475 Watts) 650 Watts (28 VDC 550 Watts) 1050 Watts (28 VDC 950 Watts)
PSU V-INPUT 28 VDC ±30%, 48 VDC ±30%, 72 VDC ±30%, 270 VDC ±30%, Autorange 90-132 VAC RMS & 180-264 VAC RMS 47-880 Hz, 3-Phase 200 VAC ±30% 47-880 Hz
STD BACKPLANE 6U (0.8" Pitch), VME64X or cPCI or VPX or Hybrid VME64X/VPX or VME64X/cPCI
BOARD FORMAT CCS: Conduction-cooled slots only or MCS: Slot-by-slot user configured card-cage allows intermixing conduction-cooled ANSI-VITA 48.2 & air-cooled ANSI-VITA 48.1 boards
FRONT PANEL AREA 101 mm x 172.5 mm 141.5 mm x 172.5 mm 243 mm x 172.5 mm
I/O SUPPORTED 6 Power Pins (23 Amp) & 365 I/O Pins (5 Amp) 6 Power Pins (23 Amp) & 822 I/O Pins (5 Amp) 6 Power Pins (23 Amp) & 1057 I/O Pins (5 Amp)
OPERATING TEMP -40 °C to +85 °C Operating Temperature, -55 °C to 100 °C Storage Temperature
MTBF 25° GB 98,000 Hours, 65° AIC 32,000 Hours25° GB 86,000 Hours, 65° AIC 28,000 Hours25° GB 78,000 Hours, 65° AIC 24,000 Hours


These highly optimized 6U chassis incorporate all proprietary technologies, features and well established mechanical & electrical solutions developed during the past 27 years.

FAC:Flow-through airflow open enclosure.

S:Standard sealed contaminant-free enclosure.

SEF:Sealed with Extended Fins contaminant-free enclosure.

SEF-HP:Sealed with Extended Fins + 18/20 Heat Pipes contaminant-free enclosure.

HES:Sealed fitted with 4 integrated heat exchangers contaminant-free enclosure.

HES-1Sealed 1" pitch, fitted with 4 integrated heat exchangers contaminant-free enclosure.

SIXHEX:Sealed fitted with 6 integrated heat exchangers contaminant-free enclosure.

SIXHEX-1:Sealed 1" pitch, fitted with 6 integrated heat exchangers contaminant-free enclosure .

SIXHEX-16HP:Sealed fitted with 6 integrated heat exchangers & 16 heat pipes contaminant-free enclosure.

SIXHEX-20HP-1:Sealed 1" pitch, fitted with 6 integrated heat exchangers & 20 heat-pipes contaminant-free enclosure.

SEVENHEX-CHP-1:Sealed 1" pitch, fitted with 7 integrated heat exchangers & 32, 36 or 46 heat-pipes contaminant-free enclosure.

6U ATR MIL Certificates

6U ATR SEF-HP Ordering Information

Generic Part Number:
CM-ATR-S5 /CT /B /I /W /3.3 /D1 /D2 /R /S /FP /TC /BC /CS /C
/S5 Enclosure Size
  • CM-ATR-25: ½ ATR - 5 Slots (0.8" Pitch).
  • CM-ATR-35: ¾ ATR - 7 Slots (0.8" Pitch).
  • CM-ATR-45: 1 ATR - 12 Slots (0.8" Pitch).
/CT Enclosure Cooling Technique
  • SEF-HP: Sealed (0.8” pitch) enclosure with Extended Fins + 18/20 Heat Pipes.
/B Backplane Type
  • VME64x: Military VME64x Backplane with 5 row 160 pin J1/J2 and 95 pin J0 connectors.
  • VME64xK: Military VME64x Backplane with 5 row 160 pin J1/J2 & 75 pin key-slot J0 connectors.
  • cPCI: Military Compact PCI Backplane.
  • VPX: Military VITA 46 VPX Backplane.
  • VPX/VME64x: Hybrid VPX mixed with VME64x Military Backplane.
  • cPCI/VME64x: Hybrid cPCI mixed with VME64x Military Backplane.
/I PSU Input Power Voltage
  • 28VDC: 28 VDC Input.
  • 48VDC: 48 VDC Input.
  • 72VDC: 72 VDC Input.
  • 270VDC: 270 VDC Input.
  • 90-264VAC: Autorange 90-264 VAC @ 47-880Hz Input.
  • 200VAC-3Ph: 200 VAC 3 Phase @ 47-880Hz Input.
/W Power Supply Unit
CM-ATR-25 - 5 Slot
  • 300W: 28 VDC (+5 VDC @20A, +3.3 VDC @5A, ±12 VDC @8A).
  • 400W: All PSUs (+5 VDC @20A, +3.3 VDC @5A, ±12 VDC @12A).
  • A-475W: 28 VDC (+5 VDC @40A, +3.3 VDC @22A, ±12 VDC @8A).
  • A-575W: All PSUs (+5 VDC @40A, +3.3 VDC @22A, ±12 VDC @12A).
  • B-450W: 28 VDC (+5 VDC @20A, +3.3 VDC @45A, ±12 VDC @8A).
  • B-550W: All PSUs (+5 VDC @20A, +3.3 VDC @45A, ±12 VDC @12A).
  • C-475W: 28 VDC (+5 VDC @20A, +3.3 VDC @22A, +12 VDC @16A, -12 VDC @8A).
  • C-575W: All PSUs (+5 VDC @20A, +3.3 VDC @22A, +12 VDC @21A, -12 VDC @12A).
CM-ATR-35 - 7 Slot
  • 400W: 28 VDC (+5 VDC @40A, +3.3 VDC @5A, ±12 VDC @8A).
  • 500W: All PSUs (+5 VDC @40A, +3.3 VDC @5A, ±12 VDC @12A).
  • C-575W: 28 VDC (+5 VDC @20A, +3.3 VDC @22A, +12 VDC @25A, -12 VDC @8A).
  • C-625W: All PSUs (+5 VDC @20A, +3.3 VDC @22A, +12 VDC @25A, -12 VDC @12A).
  • D-550W: 28 VDC (+5 VDC @40A, +3.3 VDC @45A, ±12 VDC @8A).
  • D-650W: All PSUs (+5 VDC @40A, +3.3 VDC @45A, ±12 VDC @12A).
CM-ATR-45 - 12 Slot
  • 950W: 28 VDC (+5 VDC @80A, +3.3 VDC @45A, ±12 VDC @16A).
  • 1050W: All PSUs (+5 VDC @80A, +3.3 VDC @45A, ±12 VDC @21A).
All PSUs = All PSUs except 28 VDC input
28 VDC = 28 VDC input only

/3.3 3.3VDC (CM-ATR-25 & CM-ATR-35 only)
  • 3.3-75W*: 3.3VDC @ 22A (in Lieu of 3.3 VDC @ 5A), Optional DC/DC AUX0 converter on Backplane fitted for 3.3VDC
  • NOTE: Option suited for 1st generation PSU models 300W/400W/500W. Note: If /3.3-75W is not selected, DC/DC power socket AUX0 remains free to the user
/D1 DC/DC AUX1 (CM-ATR-35 & CM-ATR-45 only)
  • D1: 100W Optional DC/DC Converter on Backplane. User defined output. Auxiliary DC/DC output options: +2VDC 50W, -2VDC 50W, +3.3VDC 75W, -3.3VDC 75W, +5VDC 100W, -5VDC 100W, +12VDC 100W, -12VDC 100W, +15VDC 100W, -15VDC 100W, +28VDC 100W, -28VDC 100W, +48VDC 100W, -48VDC 100W.
  • Ordering Examples: 48-100W » 48VDC @ 2A | -5-100W » -5VDC @ 20A | 2-50W » 2VDC @ 25A.
/D2 DC/DC AUX2 (CM-ATR-45 only)
  • D2: Optional user defined output DC/DC converter on backplane.
/R Redundant Plug-in PSU
CM-ATR- 35 & CM-ATR-45 only
  • RA-475W: 28 VDC (+5 VDC @40A, +3.3 VDC @22A, ±12 VDC @8A).
  • RA-575W: All PSUs (+5 VDC @40A, +3.3 VDC @22A, ±12 VDC @12A).
/S Temperature Supervisory Unit
  • TSU: Temperature Supervisory Unit. (Fitted as standard)
/FP Front Panel Layout
  • CMP: Standard CM front panel fitted with MIL-C-38999 connectors.
  • UDP: User defined front panel layout (requires customer drawing).
/TC Chassis Top Cover
  • FTC: Low Profile Top Cover with extended cooling fins. Fitted as standard. ‡ 20mm.
/BC Chassis Bottom Cover
  • SBC: Standard Bottom Cover. ‡ below backplane 25mm.
  • HBC: High-profile Bottom Cover. ‡ below backplane 50mm.
/CS Chassis Card-Cage Slot
  • MCS: Mixed Card-cage Slots (conduction-cooled & air-cooled boards).
  • CCS: Conducton-cooled Card-cage slots (conduction-cooled boards only).

/C Chassis Color
  • B: Black, G: Navy Grey, E: Army Dark Earth, W: White, R: Red, PT: Platinum, YW: Yellow, GN: Green, BLU: Dark Blue, CR: Chromate MIL-C-5541 or O: Other (user defined).
Part Number Example:
  • 3/4 ATR, 7 slot, 6U VMEbus Avionics Enclosure.
  • Sealed Enclosure with Extended Fins + 18 Heat Pipes.
  • Extended 7 slot cPCI Backplane for 6U boards fitted with I/O on P3, P4 and P5 connectors.
  • 28VDC input Power Supply Unit with 400W (+5VDC @40A, +3.3VDC @ 5A, ±12VDC @ 8A).
  • (+) 3.3VDC @ 22A DC/DC converter on Backplane.
  • User defined Front Panel layout.
  • Standard low-profile top cover with extended cooling fins.
  • Standard profile bottom cover.
  • Conduction only, conduction-cooled card-cage slots.
  • Enclosure Navy Grey color.