Driving circuit for an EC-motor

A control circuit (1) for an electronically commutated brushless direct current motor (M) comprising:

• a semiconductor end stage (2) which is controlled by an electronic commutation control (4) via a driver stage (6) for the time-offset control of stator coils (U,V,W) of the motor (M) for the purpose of producing a magnetic rotating field for a motor rotor depending on the rotor rotation position, wherein a supply voltage (UVCC) is supplied to a voltage supply input (VCC) of the driver stage (6) via a temperature monitor (18) placed inside the motor (M) in series in a supply line of the supply voltage of the driver stage (6),
• two redundant first and second excess current protection units (14, 16) which monitor the motor operating current,
• a measurement resistance RM arranged in series with the end stage (2) to provide an input signal for the first and second excess current protection units, and
• first and second redundant stall protection units (10, 12) which each monitor the motor (M) during operation for rotation of the rotor, wherein in the event of a determined stall status the first stall protection unit (10) deactivates the driver stage (6) and the second stall protection unit (12) shuts off the supply voltage (UVCC) for the driver stage (6);
• wherein two input signals are supplied to each of the first and second stall protection units (10, 12), including a driver signal (ST1/ST2) of the commutation control (4), and a rotor rotation position signal (SH1/SH2) from a rotation position acquisition device (H1 to H3),
• wherein further the first stall protection unit (10) is configured to deactivate the driver stage (6) by sending a control signal (SSD1) to a switch input (SD1) of the driver stage (6),
• wherein a first current limiting value of the first excess current protection unit (14) is greater than an upper threshold value of a software current limitation for the operating current, while a second current limiting value of the second excess current protection unit (16) is greater than a lower threshold value of the software current limitation for a start-up current.