Patent ID: 8378695
Filing Date: 2013-02-19
Classification: G01R,H02M,H03K,Y02B

Abstract:
1. A circuit arrangement for determining a change with time of an output voltage of a half-bridge circuit during a dead time, the half-bridge circuit comprising two switching elements that alternatingly assume an on-state and an off-state and that both assume an off-state during the dead time, the circuit arrangement comprising: a first input for applying the output voltage; a capacitive network having a first and a second circuit node each being capacitively coupled to the input, and having a terminal for a reference potential; a recharging circuit for the capacitive network that is configured, during the switched-on phase of one of the first and second switching elements, to adjust electrical potentials of the first and second nodes, the electrical potentials each being different from the reference potential; and a comparator arrangement that is configured during the dead time to determine a time difference between such times at which the electrical potentials at the first and second node each assume a given potential value, this time difference being a measure for the change with time of the output voltage, wherein the capacitive network further comprises: a third capacitance coupled to the tap of the capacitive voltage divider; the first circuit node being formed by the tap of the voltage divider, and the second circuit node being formed by a terminal of the third capacitance facing away from the tap, wherein the changeover circuit further comprises: a fourth capacitance, which by the first switch is alternatingly connectable to the second circuit node of the capacitive network, or the terminal for the reference potential; and a second switch being connected in parallel with the third capacitance of a capacitive network.