EL4x1x, EL4x2x current output
The load capacity of the EL4xxx current outputs is subject to specified operational limits. This information is provided as "max. load" in the technical data. For each channel this is the maximum load resistance against which the terminal can still provide the maximum possible output current. The relevant parameter is the number of available channels for each terminal (not the number of channels in use).
Number of channels | max. load | Characteristic | max. output voltage at max. load | typ. max. open circuit voltage without load |
|---|---|---|---|---|
2 | < 500 Ω | short-circuit-proof | 10 V | approx. 14 V |
4 | < 350 Ω | short-circuit-proof | 7 V | approx. 10 V |
8 | < 150 Ω | - | 3 V | approx. 6 V |
A channel can be operated at higher load resistances, although it will then no longer reach its full output current and be subject to overload.
 | Operation with higher load Operation outside the operating range for the respective number of channels according to the diagrams below is not recommended. If the process value specification results in operation outside this range, the output stage may become damaged. |
Parallel connection
The current outputs of the EL4xxx devices can be connected in parallel to a load if the load has a current requirement higher than 20 mA. All GND must be connected together. Channels of one terminal, but also channels of several terminals can be used for this purpose.
When designing the layout, it must be noted that Ohm's law still applies: U = R*I. If, for example, a channel with 10 V can drive its 20 mA through a 500 Ohm load (see specifications in the previous chapter), the load may only be 250 Ohm if 2 * 20 mA are to be output with two parallel connected channels of 10 V each - because the output voltage of the channels does not increase due to the parallel connection.