Spectrum M2p.59 Series, Hardware Manual, Page: 180 / 190

180 (c) Spectrum Instrumentation GmbH
Details on M2p cards I/O lines
Details on M2p cards I/O lines
Multi Purpose I/O Lines
The MMCX Multi Purpose I/O connec -
tors of the M2p cards from Spectrum
which do provide input capabilities
(X1, X2 and X3)
are protected
against input over voltage conditions.
For this purpose clamping diodes of the
types BAS516 are used in conjunction
with a series resistor. All three I/O lines
are internally clamped to signal ground
and to 3.3V clamping voltage. So when
connecting sources with a higher level
than the clamping voltage plus the for -
ward voltage of typically 0.6..0.7 V will
be the resulting maximum high-level lev -
el.
The maximum forward current limit for
the used BAS516 diodes is 100 mA,
which is effectively limited by the used
series resistor for logic levels up to 5.0V.
To avoid floating levels with unconnect -
ed inputs, a pull up resistor of 10 kOhm to 3.3V is used on each line.
The X0 output is always actively driven, hence connecting external sources might either damage the source
or the output buffer of your M2p card.
Additional I/O Lines (Option -DigFX2)
The additional Multi Purpose I/O connectors of the M2p cards -DigFX2 option from Spectrum does provide sixteen additional Multi-Purpose
I/O lines
(X4 to X19)
, which are protected against input over voltage conditions. Four of these lines can be jumper selected to be routed
to either the main multi-pin FX2 connector or to a SMB connector:
For this purpose clamping diodes of the types BAS516 are used in conjunction with a series resistor. All I/O lines are internally clamped to
signal ground and to 3.3V clamping voltage. So when connecting sources with a higher level than the clamping voltage plus the forward
voltage of typically 0.6..0.7 V will be the resulting maximum high-level level.
The maximum forward current limit for the used BAS516 diodes is 100 mA, which is effectively limited by the used series resistor for logic
levels up to 5.0V. To avoid floating levels with unconnected inputs, a pull up resistor of 10 kOhm to 3.3V is used on each line.
Image 86: electrical connection and termination of multi-purpose I/O lines
Image 87: electrical connection of additional I/O lines on connection DigFX2