Smart controller with phantom inductor current sensing for switched mode power supplies

An apparatus comprising:

• a power switch and driver block having an input voltage terminal, a ground terminal, a pulse width modulation input terminal, and a switching node output;
• an inductor having an input terminal coupled to said switching node output and having an output terminal;
• a sensing capacitor having a first terminal coupled to said output terminal of said inductor and a second, sense input terminal;
• a sensing resistor having a first terminal coupled to said second, sense input terminal of said sensing capacitor, and a second terminal comprising a pulse signal node;
• a control block having a voltage supply rail, a ground rail, a first input terminal coupled to said output terminal of said inductor, a second input terminal coupled to said second, sense input terminal of said sensing capacitor, a first output terminal coupled to said pulse signal node, and a pulse width modulation output terminal coupled to said pulse width modulation input terminal of said power switch and driver block, said control block comprising correlative logic which generates a voltage on said first output terminal equivalent to a voltage of said switching node output so as to infer a current through said inductor, said control block generating a pulse width modulation signal on said pulse width modulation output terminal, based on said inferred current through said inductor, without a direct electrical connection between (i) said sensing capacitor and said sensing resistor, and (ii) said switching node output of said power switch and driver block.