A detector tile (116) of an imaging detector array (112) includes a scintillator array (202), a photosensor array (204), which includes a plurality of photosensitive pixels, optically coupled to the scintillator array (202), and a current-to-frequency (I/F) converter (302). The I/F converter (302) includes an integrator (304) that integrates charge output by a photosensitive pixel during an integration period and generates a signal indicative thereof and a comparator (310) that generates a pulse when the generated signal satisfies predetermined criteria during the integration period. A reset device (316) resets the integrator (304) in response to the comparator (310) generating a pulse. Circuitry (320, 324) samples the generated signal at a beginning of the integration period and/or at an end of the integration period and generates quantized digital data indicative thereof. Logic (322) estimates the charge at the input of the integrator (304) based on the generated digital data.
