Pulse width modulation (PWM)
The EL2535 integrates a compact PWM output stage in the smallest of designs.
By means of the PWM output stage the pulse width modulation (PWM) of the supply voltage is used to regulate the output current of a connected ohmic/inductive load. The full supply voltage, pulsating with a certain frequency, is thereby fed to the output. A load current only develops at the inductance at the high level. The load current is not changed by changing the voltage level, but by the duration of the switch-off (pulse width) in relation to the period duration. This results in a duty factor corresponding to the pulse width divided by the period duration of between 0 and 100% and is proportional to the load current.
The figure "Operation at load with inadequate inductance" illustrates operation with an inadequate inductance. Continuous current flow is not reached. The current has "gaps". This mode of operation is not permitted.
 | Pulse width current terminals require inductive loads The load inductance should have a minimum inductance of 1 mH. Operation of the pulse width current terminals at loads with an inductance of less than 1 mH is not recommended, since the intermittent current flow prevents reference between the set value and the arithmetic mean of the current. |