SAMPLE AND HOLD COLUMN BUFFER FOR REFLECTIVE LCD

摘要

A system for generating an image in a reflective LCD (RLCD) using pulsed current sources instead of pulsed voltage sources to reduce noise and power consumption. The current is provided by a plurality of RAM-driven integrating DACs (IDAC) having a current output. Each IDAC drives one or more of a plurality of RLCD columns in conjunction with one of a plurality of operational transconductance amplifiers (OTA). Time-integration of the applied current by the intrinsic column capacitance of the RLCD creates a controlled voltage ramp on the column capacitance. A Look-Up-Table within each RAM holds a plurality of 8-bit digital values that correspond to the time-derivative of the current values.