This paper presents the design of an integrated circuit for (i) galvanostatic deposition of sensor layers on the on-chip pads, and (ii) amperometric readout of electrochemical sensors. The pA-size current generator has a temperature coefficient of 517.8 ppm/°C on average in the range of 0 to 60°C and line regulation of 4.4 %/V over a supply voltage range of 0.8-3 V. The feasibility of galvanostatic deposition on on-chip pads is validated by applying a fixed current to electrochemically deposit a gold layer, which was confirmed using optical microscope images of the on-chip electrodes.