Examples of an image sensor are disclosed. In one example, the image sensor comprises a dual-mode pixel cell operable in a first mode and in a second mode at different times, the pixel cell including a photodiode to receive incident light. The image sensor further comprises one or more configurable voltage sources coupled with the photodiode. In the first mode, the one or more voltage sources are configured to bias the photodiode to generate a quantity of charges that reflects a quantity of photons of the incident light received by the photodiode within a first exposure period. In the second mode, the one or more voltage sources are configured to bias the photodiode to generate a signal corresponding to a time when the photodiode receives a first photon of the incident light within a second exposure period for a time-of-flight measurement.