Manual ME-582x Series
Revision 0.9
3 Hardware
page 15
Meilhaus Electronic
3.4.2.2
Source Driver
Each input port is equipped with two source driver chips of type
ISO1H811G; detailed specifications see page 29.
The source output drivers are short-circuit-proof and are equipped with a
current limiting per channel. The combination of current limiting, thermal
shutdown, and automatic restart protects the circuitry against overload.
In the case of an overload condition (T
TSD
= typ. 175 °C) the related chan-
nel will switch off and on again automatically, as soon as the junction tem-
perature has fallen below the threshold of T
R
= 135 ºC. If a chip tempera-
ture of typ. 130 ºC is still exceeded, the overloaded channel remains disa-
bled and is only reactivated, if the temperature decreases below T
CR
= 110
ºC. Channels in standard (no overload) condition can be used at any time
without restrictions. In the case of an overload condition the output driver
(per port) can send an interrupt to the PC. A further security feature is a
complete disabling of a port in case of a missing ground connection.
Picture 81: ME-5820/21 outputs with source drivers
The following table shows the maximum output current I
Out
in dependency
of the number of channels in use.
Table 2: Max current of the source driver
To supply the source output drivers, an external power source has to be
connected to VCC_EXT (pin 10, 20), with sufficient power (depending on
Number Of Channels Used
1
16
32
I
OUT
[A]
0.625 A
0.370 A
0.180 A
