Abstract: A reference voltage that is consistent over various operational conditions and uses low power is provided. According to an example, an internal temperature-compensated voltage (e.g., vdd_int in 200) is generated from a power supply (e.g., vdd in 200), and a reference voltage (e.g., vref in 200) is generated from the internal voltage. The reference voltage is stored on a storage circuit (e.g., 430) that is coupled (charged) and refreshed under conditions, relative to circuit characteristics, that make low and ultra-low power operation possible.

Abstract: Power supplies are switched in a manner that mitigates parasitic shorts. According to an example, a control circuit (e.g., 310) operates primary and backup power supplies using the higher of the primary and backup supply voltages, for switching between the power supplies.

Abstract: Switching power supplies are implemented using a variety of methods and devices. According to an example embodiment of the present invention, an arrangement provides power to a circuit by selecting between a first supply and a second supply. The arrangement includes a first circuit that charges a first capacitive element using the first supply and generates a first reference voltage by distributing charge between the first capacitive element and a second capacitive element. The arrangement also includes a first comparator that compares the first reference voltage to a second reference voltage derived from the second supply and a second comparator that compares the first reference voltage to a third reference voltage. The arrangement further includes a power control circuit that selects one of the supplies based on the results of the comparisons.

Abstract: Apparatus (40) comprising a multistage charge pump (10) having an output (41) for connecting a load (Cout, KL). The charge pump (10) comprises m gain stages for charging and discharging m external stage capacitors (C) in order to provide an output voltage (Vout) at the output (41) that is about m times higher than a supply voltage (Vdd) of the charge pump (10). The charging and discharging is influenced by switches inside said charge pump (10) that are controlled by a switching signal having a switching frequency (fosc). A monitoring circuit (20) is provided that monitors temperature-induced changes of the value of an external reference capacitor (Cref). Furthermore, means (30) for adjusting the switching frequency (fosc) are employed in order to compensate variations of the gain of said charge pump (10) that are caused by the changes of the value of the m external stage capacitors (C).

Abstract: Power supplies are switched in a manner that mitigates parasitic shorts. According to an example, a control circuit (e.g., 310) operates primary and backup power supplies using the higher of the primary and backup supply voltages, for switching between the power supplies.

Abstract: A reference voltage that is consistent over various operational conditions and uses low power is provided. According to an example, an internal temperature-compensated voltage (e.g., vdd_int in 200) is generated from a power supply (e.g., vdd in 200), and a reference voltage (e.g., vref in 200) is generated from the internal voltage. The reference voltage is stored on a storage circuit (e.g., 430) that is coupled (charged) and refreshed under conditions, relative to circuit characteristics, that make low and ultra-low power operation possible.

Abstract: A method and apparatus for generating gamma corrected analogue voltages uses a first ladder resistor arrangement (34) to provides a first set of analogue voltage levels. A second set of voltages (x) is selected by programming a multiplexer arrangement (36) at the output of the first ladder resistor arrangement (34). A second ladder resistor arrangement (32) is used to provide a third set of analogue voltage levels which are at intermediate voltage levels between voltage levels of the second set (x). The output (g) is the buffered voltages of the second and third sets. This arrangement enables the amount of data that needs to be programmed to be reduced to a minimum required to implement the desired differences between the gamma functions. The voltages in the second set do not need to be evenly spaced, and more variability in the shape of the gamma curve can be provided where it is needed to best reflect different characteristics of possible displays to be driven.

Abstract: Switching power supplies are implemented using a variety of methods and devices. According to an example embodiment of the present invention, an arrangement provides power to a circuit by selecting between a first supply and a second supply. The arrangement includes a first circuit that charges a first capacitive element using the first supply and generates a first reference voltage by distributing charge between the first capacitive element and a second capacitive element. The arrangement also includes a first comparator that compares the first reference voltage to a second reference voltage derived from the second supply and a second comparator that compares the first reference voltage to a third reference voltage. The arrangement further includes a power control circuit that selects one of the supplies based on the results of the comparisons.

Abstract: Apparatus (40) comprising a multistage charge pump (10) having an output (41) for connecting a load (Cout, KL). The charge pump (10) comprises m gain stages for charging and discharging m external stage capacitors (C) in order to provide an output voltage (Vout) at the output (41) that is about m times higher than a supply voltage (Vdd) of the charge pump (10). The charging and discharging is influenced by switches inside said charge pump (10) that are controlled by a switching signal having a switching frequency (fosc). A monitoring circuit (20) is provided that monitors temperature-induced changes of the value of an external reference capacitor (Cref). Furthermore, means (30) for adjusting the switching frequency (fosc) are employed in order to compensate variations of the gain of said charge pump (10) that are caused by the changes of the value of the m external stage capacitors (C).

Abstract: The invention relates to a voltage processing unit comprising an integrated charge pump 11 for multiplying a voltage Vx applied to an input of the integrated charge pump 11 by a predetermined factor Xm. In order to enable a multiplication of an available voltage by a desired factor with a reduced required area for the integrated charge pump, it is proposed that the voltage processing unit further comprises an external voltage doubling circuit 12 for amplifying an available voltage Vdd and for applying the amplified voltage Vx to the input of the integrated charge pump 11. The invention relates equally to a corresponding method.

Abstract: The invention relates to a voltage processing unit comprising an integrated charge pump 11 for multiplying a voltage Vx applied to an input of the integrated charge pump 11 by a predetermined factor Xm. In order to enable a multiplication of an available voltage by a desired factor with a reduced required area for the integrated charge pump, it is proposed that the voltage processing unit further comprises an external voltage doubling circuit 12 for amplifying an available voltage Vdd and for applying the amplified voltage Vx to the input of the integrated charge pump 11. The invention relates equally to a corresponding method.