6U - SIXHEX-20HP - SIXHEX-1+20 Heat Pipes

SEALED COTS ATR - In 5 & 7 slot versions. Certified per MIL-461E & MIL-810F for immediate deployment. Applications up to 700 watts. Configure Now

6U - SIXHEX-20HP - SIXHEX-1+20 Heat Pipes

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

6U SIXHEX-20HP Description

Sealed, 1" pitch, high performance dry-air 6U chassis incorporates six heat exchangers, 20 super conductive heat pipes & air re-circulation fans inside. This minimum maintenance ATR is ideal for applications where ambient air is laden with hostile or harmful contaminants.


Heat is conducted to hollow sidewalls, top cover & rear panel heat exchangers where it is dissipated to the ambient environment by forced air rear fans or by vehicle air plenum. Two additional internal card-cage heat exchangers recirculate air & 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 SIXHEX-20HP chassis is available in 5 & 7 slot versions (½ ATR, ¾ ATR, 1 ATR), supporting VME, cPCI, VPX, VPX-VME & cPCI-VME hybrid backplanes. Total PSU power of up to 825 watts may be installed. Custom modifications can be designed upon request.


Internal layout is divided into 4 independent metallic partitions. I/O section at the front, card-cage, PSU section & exhaust fans at the rear. This improves EMI/EMC performance & reduces PSU noise on system electronics.

This 1" pitch chassis has been designed exclusively for VME wedgelock IEEE P1101.2, Compact PCI 1101.2/IEC/118/ CD and VPX VITA 46.0/.1/.10/.3/.4/.7 conduction cooled modules. A mixed card-cage, supporting air-cooled and conduction-cooled modules my be selected upon request.

6U SIXHEX-20HP Performance



Slots / Pitch:5 | 7   1"

Sealed (Dry Air):

≤ 700W

The 6U SIXHEX-20HP chassis is suitable for high wattage sealed applications that demand superior cooling capability.

Chassis Global Thermal Resistance (CGTR) coefficient:
ΔT/W = 0.050°C (½ ATR) | 0.043°C (¾ ATR).

Chassis Payload Thermal Resistance (CPTR) coefficient:
ΔT/W = 0.0596°C (½ ATR) | 0.0497°C (¾ 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 SIXHEX-20HP Backplanes

CM 6U SIXHEX-20HP 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. SIXHEX-20HP backplanes are 1" pitch & deliver full compatibility with 0.8" pitch modules.

CM ATR SIXHEX-20HP - 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 SIXHEX-20HP 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 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.

The final slot in SIXHEX-20HP 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 SIXHEX-20HP - 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.
Read More

6U SIXHEX-20HP Power Supplies

6U SIXHEX-20HP (1'' Pitch) 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 825 watts. Available in different versions to suit the demand per DC Line of standard COTS open busses.


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.

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.


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.

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

6U SIXHEX-20HP (1'' Pitch) model PSUs incorporate isolated DC/DC converters and oversized hold-up capacitors to ensure proper operation during short power line failures. Outputs are protected against short-circuit, thermal-shutdown etc. PSUs are custom made to match the enclosure mechanics.

This 6U ATR Chassis is currently only available in 5 & 7 slot versions
6U 1 Inch Pitch 825W PSU

The PSU in SIXHEX-20HP 1" pitch models is attached to a heat ecxhanger panel that provides both conduction and convection cooling. Internal air recirculation dissipates heat generated by the PSU through its panel via thermal conduction to the chassis frame.

Forced air that is drawn through the heat exchangers, passing over the PSU panel external fins & exhausted, removing the majority of heat.

6U ATR SIXHEX-20HP Features

6U SIXHEX-20HP Rear Fan Assembly
Rear Fan Options
6U SIXHEX-20HP chassis are equipt with twin Rotron Military PX3 exhaust fans (-54°C to +125°C) or Rugged fans (-10°C to +70°C).
6U SIXHEX-20HP 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 SIXHEX-20HP 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 SIXHEX-20HP Panel Covers
Top/Bottom Covers
Removable Heat Exchanger Top Cover fitted as standard. High Profile Heat Exchanger covers are available for additional clearance.
6U SIXHEX-20HP Chassis Metalwork
Chassis Metalwork
Precision machined aeronautical aluminum with MIL-DTL-5541F chromate coating. All panels & joints incorporate EMI gaskets.
6U SIXHEX-20HP 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 SIXHEX-20HP Internal Air Recirculation
Air Recirculation
Incorporating a low profile internal fan pack (4 fans) to recirculate air, improving card-cage, PSU & module heat dissipation.
6U SIXHEX-20HP Six Heat Exchangers
Six Heat Exchangers + 20HP
Fitted with 6 heat exchangers in top cover & rear PSU panel, both lower internal card-cage walls & in both sidewalls + 20 heat pipes.


  • Contaminant-free enclosure
  • Available in ½ ATR, ¾ ATR versions
  • VPX ready (1.0" Pitch)
  • 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 700W* Total Payload Power (30ºC Delta-T)
  • Integrated Temperature Supervisory Unit (TSU)
  • 50°C less than conventional 6U ATRs
  • 6 Integrated Heat Exchangers
  • 20 integrated heat pipes (Ø 8mm)
  • Dramatically increases payload MTBF by 5x*
  • 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)
  • Customizable to specific requirements
  • Low Profile Mounting Tray with quick release
  • Manufactured with US MIL components
* Subject to operating conditions

6U ATR SIXHEX-20HP Specifications

WIDTH 203 mm 254 mm
HEIGHT 259 mm 259 mm
DEPTH 510 mm 510 mm
WEIGHT 10.2 Kg 14.2 Kg
CGTR COEFF ΔT/W = 0.050°C ΔT/W = 0.043°C
CPTR COEFF ΔT/W = 0.0596°C ΔT/W = 0.0497°C
HEAT PIPES All SIXHEX-20HP Models Integrate 20 Heat Pipes - ⌀ 8mm
PSU MAX POWER 825 Watts (28 VDC 675 Watts) 825 Watts (28 VDC 675 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 (1" 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
EXT. REAR FAN 2 x Rotron PX3 2 x Rotron PX3
F115-400 200 CFM 200 CFM
F200-400 280 CFM 280 CFM
F28 200 CFM 200 CFM
F115-60 200 CFM 200 CFM
F220-50 200 CFM 200 CFM
FRONT PANEL AREA 161 mm x 170 mm 212 mm x 170 mm
I/O SUPPORTED 6 Power Pins (23 Amp) & 504 I/O Pins (5 Amp)6 Power Pins (23 Amp) & 798 I/O Pins (5 Amp)
OPERATING TEMP -40 °C to +85 °C Operating Temperature, -55 °C to 100 °C Storage Temperature
MTBF 25° GB 82,000 Hours, 65° AIC 27,000 Hours25° GB 80,000 Hours, 65° AIC 26,000 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 SIXHEX-20HP Ordering Information

Generic Part Number:
CM-ATR-S5 /CT /I /W /3.3 /D1 /R /S /FP /TC /BC /CS /F /G /C
/S5 Enclosure Size
  • CM-ATR-125: ½ ATR Long Size - 5 Slots (1" Pitch).
  • CM-ATR-135: ¾ ATR Long Size - 7 Slots (1" Pitch).
/CT Enclosure Cooling Technique
  • SIXHEX-20HP: Sealed (1" Pitch) enclosure with 6 Heat Exchangers in sidewalls, top cover, rear panel, internal card-cage & integrates 20 heat pipes (⌀8mm).
/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.
  • VME64x/cPCI: Hybrid VME64x mixed with cPCI 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 @ 47-880 Hz Input.
  • 200VAC-3Ph: 200 VAC 3 Phase @ 47-880 Hz Input.
/W Power Supply Unit
CM-ATR- 1 25 PSU
  • 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).
  • A-675W: 28 VDC (+5 VDC @80A, +3.3 VDC @22A, ±12 VDC @ 8A).
  • A-775W: All PSUs (+5 VDC @80A, +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).
  • B-565W: 28 VDC (+5 VDC @20A, +3.3 VDC @80A, ±12 VDC @ 8A).
  • B-665W: All PSUs (+5 VDC @20A, +3.3 VDC @80A, ±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).
  • C-775W: 28 VDC (+5 VDC @20A, +3.3 VDC @22A, +12 VDC @41A, -12 VDC @8A).
  • C-825W: All PSUs (+5 VDC @20A, +3.3 VDC @22A, +12 VDC @41A, -12 VDC @12A).
CM-ATR- 1 35 PSU
  • 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).
  • A-675W: 28 VDC (+5 VDC @80A, +3.3 VDC @22A, ±12 VDC @8A)*.
  • A-775W: All PSUs (+5 VDC @80A, +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).
  • B-564W: 28 VDC (+5 VDC @20A, +3.3 VDC @80A, ±12 VDC @8A)*.
  • B-664W: All PSUs (+5 VDC @20A, +3.3 VDC @80A, ±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).
  • C-775W: 28 VDC (+5 VDC @20A, +3.3 VDC @22A, +12 VDC @41A, -12 VDC @8A)*.
  • C-825W: All PSUs (+5 VDC @20A, +3.3 VDC @22A, +12 VDC @41A, -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)*.
  • E-550W: 28 VDC (+5 VDC @20A, +3.3 VDC @45A, +12 VDC @16A, -12 VDC @8A)*.
  • E-650W: All PSUs (+5 VDC @20A, +3.3 VDC @45A, +12 VDC @21A, -12 VDC @12A)*.
  • F-575W: 28 VDC (+5 VDC @40A, +3.3 VDC @22A, +12 VDC @16A, -12 VDC @8A)*.
  • F-675W: All PSUs (+5 VDC @40A, +3.3 VDC @22A, +12 VDC @21A, -12 VDC @12A)*.
CM-ATR- 1 35 Dual Redundant PSU
  • R2x500W: (+5 VDC @25A, +3.3 VDC @23A, ±12 VDC @12A).
All PSUs = All PSUs except 28 VDC input
28 VDC = 28 VDC input only

/3.3 3.3VDC (CM-ATR- 1 25 & CM-ATR- 1 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- 135 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.
/R Redundant Plug-in PSU
CM-ATR- 135 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 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 + Wiring clearance
  • STC: Standard Top Cover. ‡ 20mm.
  • FTC: Low Profile Top Cover with cooling fins. ‡ 20mm.
  • HTC: High-profile Top Cover. ‡ 35mm.
  • HETC: Heat Exchanger Top Cover. ‡ 20mm. (Fitted as standard).
  • EHETC: Extended Heat Exchanger Top Cover. ‡ 35mm.
/BC Chassis Bottom Cover + Wiring clearance
  • SBC: Standard Bottom Cover. ‡ 20mm.
  • HBC: High-profile Bottom Cover. ‡ 50mm. (Fitted as standard).
/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). (Fitted as standard).
/F Rear-mounted Fan Assembly
Fans Pack available CM-ATR-125 & CM-ATR-135
  • F115-400: 2x Rotron PX3 Military fan fitted for 115VAC @ 400Hz (100CFM each).
  • F200-400: 2x Rotron PX3 Military fan fitted for 200VAC @ 400Hz 3-Phase (140CFM each).
  • F28: 2x Rotron PX3 Military fan fitted for 28VDC (100CFM each).
  • F115-60: 2x Rugged fan fitted for 115VAC @ 60Hz (100CFM each).
  • F220-50: 2x Rugged fan fitted for 220VAC @ 50Hz (100CFM each).
Vehicle air-plenum assembly
  • VAP: Vehicle Air-Plenum according to customer specifications (external forced air source).

/G Fan Finger Guards
  • STDG: Standard Rotron PX2/PX3 finger guards.
  • EMIG: Optional EMI shielding finger guards with honeycomb filter.
  • GNF: Optional finger guards with low acoustic noise filter (-5dB).
/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, VPX Avionics Enclosure.
  • Six Heat Exchangers + 20 heat pipes.
  • Extended 1" Pitch 7 slot VITA 46 VPX Backplane for 6U boards.
  • 28VDC input Power Supply Unit with F-575W (+5VDC @ 40A, +3.3VDC @ 22A, +12 VDC @16A, -12 VDC @8A).
  • (+) 24VDC @ 4A DC/DC AUX1 user output on Backplane.
  • Temperature Supervisory Unit (standard).
  • Standard CM Computer Front Panel.
  • Heat Exchanger top cover as standard.
  • Extended high profile bottom cover as standard.
  • Conduction-cooled Card-cage Slots (conduction-cooled boards only).
  • 2x Rotron PX3 military fan fitted for 28VDC installed at the rear (200CFM total).
  • Rotron EMI shielding finger guards.
  • Enclosure Black color.