CIRCUIT AND METHOD FOR MANAGING AN INRUSH CURRENT
FIG4 illustrates a schematic diagram of another circuit for managing an inrush current
FIG4 illustrates another circuit for managing the inrush current. In the circuit of FIG4, a first capacitor CL1 is coupled between the switch S1 and the terminal for negative supply potential GND. An inductance L1 is coupled between the load 2 and a common node between the switch S1 and the first capacitor CL1. A second capacitor CL2 is coupled in parallel to the load 2 between the inductance L1 and the terminal for negative supply potential GND. The inductance L1 and the second capacitor CL2 form an LC circuit (resonant circuit). The second capacitor CL2 may be an electrolytic capacitor, for example. The use of two load capacitors CL1, CL2 is only an example. Any other number of load capacitors CL1, CL2 may be used in the circuit, depending on the application.
schematic diagram
4
control unit
2
load
42
sense unit
44
switching unit
3
560µF ∗ about
['1. A circuit for managing an inrush current (ic) of a load (2), wherein the load (2) is coupled between a voltage source (V1) and a terminal for a negative supply potential (GND), the circuit comprising: a switch (S1) coupled between the voltage source (V1) and the load (2), and configured to connect the load (2) to or disconnect the load (2) from the voltage source (V1); at least one load capacitor (C L ) coupled in parallel to the load (2) between the switch (S1) and the terminal for negative supply potential (GND); and a control unit (4), wherein the control unit (4) comprises a sense unit (42) and a switching unit (44), the sense unit (42) is configured to determine the inrush current (ic) when the switch (S1) is closed to connect the load (2) to the voltage source (VI), the switching unit (44) is configured to control the switching of the switch (S1) depending on the inrush current (ic),  characterised in that the sense unit (42) comprises a sense resistor (Rs), a sense capacitor (Cs), and a first operational amplifier (OpAmp1), the sense resistor (Rs) and the sense capacitor (Cs) are coupled in series between the switch (S1) and the terminal for negative supply potential (GND), in parallel to the load (2); and the first operational amplifier (OpAmp1) is configured to determine a current through the sense resistor (Rs) and to provide a sense voltage, wherein the current through the sense resistor (Rs) depends on the inrush current and the sense voltage depends on the current through the sense resistor (Rs).']