There are 3 designs of Backplane, all in various slot sizes.

Please contact us if you would like the backplanes fitted with connectors and then electrically tested.

Microbus: Available with 64/96 and 96/96 connectors, this design of Backplane has committed two Power ( pin2 & 31 , a,b,c rows) & 0v rails (pin 1 & 32 a,b,c rows). The two 0v rails can be independent if required by breaking the common 0v track. For technical information click here

Ordering information For more technical information please click here

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Un-committed Backplane: These backplane have total flexibility so that the power planes can be connected to any pin posititon.

Ordering information For more technical information please click here

Multilayer Microbus: 3 layer pcbs with 0v guard tracking between all signal lines. Characteristic impedance of Zo= 100 ohms. Fitted with spade termnals for excellent power distribution. The 20 slot is compatible with VMEbus mechanical specifications and can be used for P2 applications. Fitted with 96/96 Press Fit connectors.

Ordering Information For more technical information please click here

Microbus Technical details:

• PTH backplanes designed for use with microprocessors
  Reliability of plated through holes
• Minimal crosstalk
• DIN 41612 connectors
• DIN 41494 (KM6-II) compatible
• Choice of connector styles and pitches:

15,24mm for PCB’s for hard wired daughter boards
20,32mm for two level wirewrap daughter boards

96/96 Version

Ideal for high speed applications using 96/96 way connectors,screening is provided on row b between each signal track on the backplane and, via the connector, through onto the individual cards. Alternatively, for slower applications the 96/96 way connector allows the use of a maximum of 84 separate signal lines by simply breaking the 0V commoning line in the end position. Using either of these methods input/output connections are generally made at the front end of the individual plug-in boards. If a 64/96 way connector is used on the system, the 0V screen is still a feature of the Microbus, with the added advantage of input/output connections being possible from the rear of the system.

When using 0V and two power rails, pin 1 and 32 on rows a, b and care fully committed to 0V and commoned together at one end. Two separate Vcc planes are provided for dual voltage systems and are committed to pins 2 and 31 on rows a, b and c. If 0V and three powerrails are required the same situation exists as for two power rails except that it is now necessary to convert 0V on pins 32 a, b and c to Vcc by simply cutting the 0V link on the extreme edge of the connector side of the backplane. Power onto the 0V and Vcc planes is made via plated through holes positioned beneath the connector fixing screws.

64/96 Way version

A low cost version of the Microbus backplane still with the reliability of plated through holes but restricted in use to only 64/96 way connectors. The basic design is very simple, with pin 1 and 32 on rows a and c committed to 0V with a complete 0V screen over one side of the board. Pin 2 and 31 on rows a and c are committed to Vcc. This leaves 56 separate signal lines from pin 3 a and c to pin 29 a and c inclusive.

Crosstalk

Tests have been carried out on the 84HP version by feeding a 1MHz square wave signal (5ns rise and fall times), through a DIN41612 connector and measuring the adjacent tracks at the opposite end.

Note: The Microbus motherboard was not terminated, which would have reduced the amplitude to the crosstalk and changed its shape considerably.

Results: 96/96 way Microbus

Worst case in row c (square wave fed on row a) amplitude of crosstalk was 15% with only 8% on adjacent tracks in the same row.

Results: 64/96 way Microbus

Worst case in row c (square wave fed on row a) amplitude of crosstalk was 35% of main signal reducing further away from the main signal line. Adjacent tracks on the same row were 25-30% amplitude.