Resources Contact Us Home
Microcontroller chip with integrated LCD control module and switched capacitor driver circuit

Image Number 3 for United States Patent #5861861.

Apparatus for providing multiple of discrete voltage levels to drive a liquid crystal display (LCD) from an LCD module on board a microcontroller chip includes a charge pump with a switched-capacitor that develops the discrete voltages as multiples of the value of a base voltage that remains substantially without change irrespective of change in the supply voltage. A switched-capacitor charging circuit selectively charges a capacitor to produce successive additive charges individually retrievable from the capacitor. An LCD drive selectively transmits the discrete voltage levels to activate the LCD according to status of an external system under the control of the microcontroller. Voltage losses that may occur during the switched-capacitor charging are compensated to maintain the levels of the discrete voltages free of decay. Compensation is achieved by overcharging the capacitor by an amount substantially equivalent to the amount of voltage loss on the capacitor, using active feedback obtained from monitoring the charge on the capacitor.

  Recently Added Patents
Shot scent dispenser
Metal melting apparatus and method for melting metal
Predictive time entry for workforce management systems
Specification of latency in programmable device configuration
Copolymer for positive type lithography, polymerization initiator used in production of said copolymer, and composition for semiconductor lithography
Flavonoid dimers and methods of making and using such
Amplitude-shift-keying (ASK) envelope detector and demodulation circuits
  Randomly Featured Patents
Brushless type of vehicular AC generator
Image processing apparatus
Photovoltaic cell fabrication method and panel made thereby
Method of grain refining cast magnesium alloy
Ultrasound echogenic cardiac lead
Semiconductor device and method of manufacturing the same
Vapor recovery detection means
Horizontally-oriented gasifier with lateral transfer system
Magnetic recording medium comprising a magnetic film layer and a coating of purified perfluoropolyether lubricant
Device for the timely feeding of cartridges in semi-automatic rifles