Some simulations on reported issues Wei Wei 2018-12-17

Problem 1：the addr encoder output level The address encoder used a kind of dynamic logic There might be some risk when this gate is no refreshed for a long time– the leakage will let the held charge disappear Simulation showed that when not refreshed after several ms, the held voltage will drop to ~600mV, which might cause some quiescent current problem Dynamic logic

Solution 1 However, when we read the address again (refreshed) at 2ms, simulation showed that the output charge can return to normal level This means this encoder needs to be “frequently” readout Luckily, every column will be hit within 8.3us averagely, which is far less than its leakage time, generally there will be no problem We should not forget, whenever restart to work after a long time, the pixel array should be set and read first, this is to refresh the addr encoder

Preliminary consideration of the schedule From MOST2 project 05/2018 ~ 04/2019 the first MPW to be tapeout