This paper presents a study of two architectures for designing an integrated CMOS Laser Diode Driver (LDD) intended for a 3D image sensor used in mobile applications and based on the indirect Time-of-Flight (iToF) measurement. Architectures are focused on two different driving topologies: series and shunt which means the laser diode is connected either in series or parallel with a switching element in order to provide laser pulses. Two LDD prototypes implemented in a 130 nm CMOS technology are able to provide programmable current pulses up to 3 A with a 2.5 ns pulse width at a maximum 200 MHz Pulse Repetition Frequency (PRF).