In this paper, a digital pixel sensor in silicon on insulator (SOI) is presented. The active part is a partially depleted SOI phototransistor. The technique elaborated in Harik et al. (2008)  was designed and implemented. Moreover, we took advantage of some of the characteristics of the floating body SOI MOSFET to implement a first order delta sigma modulator in each pixel. Measured data show that the pixel has a sensitivity of 3 mW/m2 and a resolution of about 7 bits. This pixel can be operated in two modes: weak inversion (Idc=1.2 μA) and moderate inversion (Idc=15 μA). © 2010 Elsevier Ltd. All rights reserved.