US Patent No. 9,537,399

DIRECT CURRENT CONTROL WITH LOW E-M EMISSION


Patent No. 9,537,399
Issue Date January 03, 2017
Title Direct Current Control With Low E-m Emission
Inventorship Christian Paintz, Erfurt (DE)
Thomas Freitag, Plaue (DE)
Heiko Grimm, Waltershausen (DE)
Enrico Reinhardt, Bad Langensalza (DE)
Assignee MELEXIS TECHNOLOGIES NV, Tessenderlo (BE)

Claim of US Patent No. 9,537,399

14. A switching control circuit for driving a flow of direct current through an at least partially inductive load, the switching
control circuit comprising:
a first semiconductor switch having a control terminal for receiving a control current, said control current controlling the
resistance of a path between a load terminal, for connecting to said at least partially inductive load, and a supply terminal,
for connecting to a supply voltage source;

a semiconductor freewheeling component coupled between said load terminal and ground;
a controller for adjusting said control current in order to activate or deactivate the flow of current to said load terminal;
wherein said controller comprises a timer element for initiating a timed adjustment of the control current during a cycle
for activation or deactivation of the flow of current through the first semiconductor switch so as to anticipate a state change
of a component of the switching control circuit, the controller being configured to determine a timing for the timed adjustment
in a predictive manner based on a measurement in an earlier cycle for switching the first semiconductor switch, and

wherein the controller further comprises a multiplexer configured to select parameters from a parameter storage element, the
parameters being associated with the current state of the control circuit and providing these parameters to the timer element
and to two or more charge or discharge switches configured to turn on and off each of the at least one semiconductor switch,
the strength of the turn-on and turn-off currents being dependent on the multiplexer output parameters.