Pixel voltage regulator

A pixel circuit comprising a photodetector pixel arrangement and a voltage regulating circuit adapted for applying a target voltage on the pixel arrangement,

• the photodetector pixel arrangement comprising at least one pixel comprising a photodetector, an integrator for accumulating a signal from the photodetector, and a source following output transistor for amplifying the integrated signal,
• the photodetector pixel arrangement comprising a current source for biasing the source following output transistor by applying a readout current through the source following output transistor,
• the voltage regulating circuit comprising an amplifier, at least one replica transistor, and a replica current source, wherein
• a gate of the at least one replica transistor is electrically connected with an output node of the amplifier, and the output node of the amplifier is electrically connected with the pixel arrangement for providing the target voltage,
• a drain of the at least one replica transistor is adapted to be electrically connected, during operation, with a power supply,
• and a source of the at least one replica transistor is electrically connected with a negative input of the amplifier, and with the replica current source,
• wherein the voltage regulating circuit is arranged such that, during operation, a predefined reference voltage can be applied to a positive input node of the amplifier,
• and wherein the at least one replica transistor is dimensioned substantially the same as the output transistor of the at least one pixel and wherein the replica current source is adapted for providing substantially the same current through each replica transistor as the readout current.