In this work, an organic memory device with memcapacitive properties called pinMOS is studied. From the C-V curves for different stimuli and based on the device structure, an electrical model for the charge storage is presented. The capacitance modulation is obtained by the change of the depletion layer's width due to this internal potential. The proposed model is implemented on Verilog-A and simulated, while two main features of the device, namely the hysteresis in the capacitance and its pulsed bias response (resembling synaptic long-term potentiation and depression) are measured and compared to the simulation results.