A Triple-Mode Programmable 12V Charge Pump for High Dynamic Range Photodiode Array Biasing

Abstract

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 high voltage required for biasing different types of photodiodes. The charge pump exhibits a reliable voltage range extending from 2V to 12V in 65nm bulk CMOS technology. The large voltage range is used to bias different types of photodiodes to achieve a high dynamic range for the photodetector array. 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, namely, Single Photon Avalanche Diode (SPAD), Avalanche Photodiode (APD), and Linear Photodiode (PD) with 64% power efficiency when consuming 120μA..