| 摘要 |
<p>A microcontroller (50) chip (51) includes a charge pump with a switched-capacitor (83) that develops a plurality of discrete voltages. A switched-capacitor (83) charging circuit selectively charges a capacitor to produce successive charges individually retrievable from the capacitor. An LCD driver (173) selectively transmits the discrete operating voltage levels to activate the LCD (10) according to status of an external system under the control of the microcontroller (50). Voltage losses that may occur during the switched-capacitor (83) charging are compensated to maintain the levels of the discrete operating voltages free of decay. Compensation is achieved by overcharging the capacitor (83) 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.</p> |
