This document presents the general principle of LCD screens and the cause of flicker. It also proposes a solution of automatically minimizing flicker using the STVM100 (LCD VCOM calibrator).
Liquid crystal displays (LCDs) are prone to visible flickering if the common voltage (VCOM) deviates from its ideal value due to manufacturing process variations. Traditionally, this was adjusted using mechanical potentiometers, which lacked accuracy and robustness.
This document presents a solution using the STVM100 digital VCOM calibrator. The note details the principle of LCD flicker, explains how the STVM100 replaces mechanical adjustments with a precise digital interface to control sink current, and describes an automated system for fully adjusting VCOM to eliminate flicker.
The STVM100 provides a gray scale accuracy out of a range of 128.
The system offers fast adjusting with an average time of less than 3.2 seconds.