A LIDAR system includes a receiver configured to receive a reflected light beam from a receiving direction, the reflected light beam having an oblong shape that extends in a lengthwise direction. The LIDAR receiver includes a two-dimensional (2D) photodetector array including a plurality of pixel rows and a plurality of pixel columns, wherein the reflected light beam, incident on the 2D photodetector array, extends in the lengthwise direction along at least one receiving pixel column of the plurality of pixel columns according to the receiving direction; an analog readout circuit including a plurality of output channels configured to read out electrical signals; and a multiplexer configured to, for each reading cycle, selectively couple receiving pixels of the at least one receiving column to the plurality of output channels based on the receiving direction, while decoupling non-receiving pixels from the plurality of output channels based on the receiving direction.