Method and circuit arrangement for determining a resistance

A method of determining a resistance of a first drive transistor in a drive system for operating a motor, the drive system comprising a first drive transistor, a first sense transistor, and a second drive transistor, wherein the first sense transistor is arranged in parallel with the first drive transistor, each transistor comprising a control terminal, a first channel terminal, and a second channel terminal, the method comprising:

• switching the first and second drive transistors to operate the motor using an operating current, wherein current is configured to flow between the first and second channel terminals of each drive transistor in an on-state such that the operating current flows between motor coils of the motor and a reference node, and wherein the reference node is shared by each of the transistors;
• and
• operating the first sense transistor to determine the on-state resistance of the first drive transistor, wherein the operating current flows between motor coils of the motor and the reference node through the first sense transistor.