Voltage sensing circuit and method

An integrated circuit comprising a voltage sensing function to sense a voltage across an external circuit component, comprising

• a sensing input to be connected to a sensing terminal of a voltage divider which is connected in parallel with the external circuit component, wherein said sensing terminal is coupled to the external circuit component via a voltage clamping component;
• a voltage detector adapted to determine a sense signal voltage at the sensing input;
• a current injector to inject current to the sensing terminal if the sense signal voltage is below a minimum threshold, thereby indicating a fault, wherein the voltage detector is then adapted to determine a sense signal voltage at the sensing input in response to the injected current from the current source;
• and
• a controller to determine if the fault is caused by the voltage divider or by an external circuit component connected in parallel with the voltage divider, based on the sense signal voltage in response to the injection of current by comparing the sense signal in response to the injected current and a clamping voltage of the voltage clamping component.

A voltage sensing method for sensing a voltage relating to a circuit component between a first terminal and a second terminal, the method, comprising:

• receiving a first sense signal from a sensing terminal between first and second resistors in series that forms a voltage divider, the first sense signal indicating a voltage across a circuit component being sensed, wherein there is a voltage clamping component coupled from the sensing terminal to the circuit component;
• detecting if the first sense signal has dropped below a minimum threshold and in response controlling a current injector to inject a current into the sensing terminal;
• detecting a second sense signal in response to the injection of current;
• and
• determining if the fault is caused by the circuit component or by the voltage divider based on the second sense signal, by comparing of the second sense signal in response to the injected current and a clamping voltage of the voltage clamping component.