The analog driver for a display device which is controlled by current, such as an LED, includes a strobed analog input which charges a storage capacitor. The voltage across the storage capacitor is fed to the positive input of a comparator. The negative input of the comparator receives the voltage from...http://www.google.se/patents/US6097360?utm_source=gb-gplus-sharePatent US6097360 - Analog driver for LED or similar display element
