This paper proposes a programmable 12V charge pump output supplied from a 2.5V supply in 65nm CMOS technology. The programmable charge pump consists of a unit stage that can work in both charging and discharging modes. This unit stage is cascaded to provide the programmable voltage required for biasing different types of photodiodes. The proposed charge pump, with an area of 0.07 mm2, adds no extra mask cost as the devices used are standard thick-oxide devices. The charge pump drives a 100pF load capacitor at 50 kHz switching frequency between the three available modes with 64% peak power efficiency.