Node voltage control

A circuit portion comprising:

• an analog voltage supply module arranged to receive a bias voltage and arranged to supply a voltage to a node;
• a clock;
• and
• a digital control module clocked by the clock;
• wherein the circuit portion is arranged to:
• sample the voltage at the node at a signal edge of the clock, to obtain a sampled voltage, and store the sampled voltage;
• disable the bias voltage to the analog voltage supply module and supply the sampled voltage to the node;
• and
• subsequently generate a refresh signal in response to at least one refresh criterion being met;
• and
• wherein the digital control module is arranged to:
• receive the refresh signal;
• and
• initiate a refresh sequence, in response to the digital control module receiving the refresh signal, comprising:
• re-applying the bias voltage to the analog voltage supply module;
• re-sampling the voltage at the node at a signal edge of the clock to obtain a re-sampled voltage;
• and
• storing the re-sampled voltage.