Microcontroller chip with integrated LCD control module and switched capacitor driver circuit

A semiconductor device implemented in a complementary metal-oxide-silicon (CMOS) chip including a microcontroller integrated in the chip for controlling selected parameters of a system external to the chip, and an LCD module integrated in the chip for providing multiple discrete voltage levels to drive a liquid crystal display (LCD) adapted to operate in conjunction with said external system to display at least some of said parameters, comprising:

• switched-capacitor means for developing said multiple discrete voltage levels as multiples of a base voltage level derived from a supply voltage for the device, including a switched-capacitor charging circuit for selectively charging a capacitor to produce successive additive charges individually retrievable from the capacitor as respective ones of said discrete voltage levels at least some of which are of greater magnitude than said supply voltage;
• LCD drive means for selectively transmitting said discrete voltage levels to activate the LCD display according to a status of at least some of said parameters of the system to be controlled by the microcontroller;
• and
• timing means integrated in the microcontroller chip for supplying timing signals to the LCD module for operational timing of the LCD display.

Apparatus for providing multiple discrete regulated voltage levels to drive a liquid crystal display (LCD) from an LCD module implemented within the integrated circuit of a microcontroller chip, wherein the LCD display operates in conjunction with a system external to the chip controlled by the microcontroller chip, comprising:

• means for developing the multiple discrete regulated voltage levels as multiples of a base voltage level derived from a supply voltage and which remains substantially constant independent of the supply voltage level, said discrete level-developing means including at least one capacitor and switched-capacitor means for charging said at least one capacitor to obtain successive additive charges as said multiples of the base voltage level, with each multiple being individually retrievable from said at least one capacitor;
• means responsive to said discrete level-developing means for selectively applying the discrete regulated voltage levels developed thereby to activate the LCD display;
• and
• internal clock means in the microcontroller chip for supplying clock signals to the LCD module for maintaining the operational timing of the LCD display.