In this paper

we describe a non-gated charge-to-time converter covering the dynamic range of 180-5000 mV in bipolar input voltage from the 448 pre-amplified outputs of TOF detectors for Beijing Spectrometer Ⅲ at the Beijing Electron Positron Collider(Phase II).With the error of less than 10 mV

the circuits work well for correcting the time-walk effect.This is essential for measurements of the time resolution of better than 25 ps.The converter is simple

stable

and is intended for multi-channel systems.