A switched current source circuit, comprising first and second voltage source nodes; a load; a current source; and capacitor switching circuitry comprising a load node, a capacitor and a plurality of switches configured, based on a control signal, to adopt a biasing configuration followed by an active configuration, wherein in the biasing configuration, the load node is conductively connected to the second voltage source node to bias a voltage level at the load node, and the capacitor is connected so that it at least partly charges; and in the active configuration, the load node is conductively connected via the load to the first voltage source node, and via the capacitor to the current source to increase a potential difference between the first voltage source node and the load node.