Meilhaus Electronic ME-1000 Series, Manual

Page: 13 / 48

Manual ME-1000 Rev. 1.4E
Meilhaus Electronic Page 13 Hardware
Diagram 2: Switching of ME-1000
The current load of the board (without convection) can be
approximated using the following formula:
T
J
≥
T
u
+ (14°C/W x P
G
)
T
J
= max specified operation temperature of the component
of 70 °C
P
G
= total load of the outputs used
T
u
= surrounding temperature (without convection)
3.5 Pull up/Pull down Resistors
On power up, all ports are set as input and are in a high impe-
dance state (without an external switching). Depending on the
application, it may be necessary to set the I/O-lines in a defined
state on power up by using pull up or pull down resistors. The
design of the ME-1000 allows these to be placed directly on the
base board for all 64 resp. 128 lines as required. Resistor arrays
of 4.7 k
Ω
(recommended) can be added individually for each
port. Note that when pull up resistors are used, the current out-
put of the lines is decreased (e. g. if R
up
=4,7 k
Ω
I
max
=3,1 mA).
Digital In
Digital Out
PC-GND