Abstract: A power supply system is provided for a multiple lamp LCD panel. In one aspect, the power supply includes a plurality of transformers for driving a plurality of respective CCFLs. The primary sides of each transformer are coupled in series to thereby reduce the stress on each transformer. For LCD panels that include longer CCFLs, a power supply is provided that includes a plurality of transformers for driving a plurality of respective CCFLs. The primary sides of each transformer are coupled in series and each lamp is coupled to two secondary sides of the transformers, thereby reducing the problems associated with longer CCFL tubes. In any of the embodiments, the power supply can be adapted to convert a high voltage DC signal to high voltage AC used to power the lamps.

Abstract: An adaptive LCD power supply circuit for adjusting at least one supply parameter in response to at least one load parameter of an associated load includes a feedback path configured to sense at least one load parameter and provide a control signal representative of at least one load parameter, and a regulating circuit configured to accept the control signal and regulate at least one supply parameter based on the control signal. The feedback path may include a first path to provide a first signal representative of a load condition of a first module, and a second path to provide a second signal representative of a load condition of a second load module, and a minimum decision circuit to output a third signal equal to the lesser of the first and second signals. An electronic device including an adaptive LCD power supply circuit is also provided.

Abstract: A DC to DC converter having improved transient response, accuracy, and stability. The DC to DC converter includes a first comparator configured to compare a first signal with a second signal. The first signal has a DC offset determined, at least in part, by a DC reference voltage source. The second signal is representative of an output voltage level of the DC to DC converter. The comparator is further configured to provide a control signal to a driver based on a difference between the first signal and the second signal, the driver driving the output voltage of the DC to DC converter. The DC to DC converter further includes an accuracy circuit to enhance accuracy of the DC to DC converter. The DC to DC converter may further include a stability circuit to enhance stability of the DC to DC converter.

Abstract: A compensating circuit for providing a compensating control signal to a regulating circuit is provided. The compensating circuit includes a multiplying circuit and a miller capacitor. The multiplying circuit may provide a predetermined multiplication factor to a miller current level based on a resistor ratio. The multiplying circuit may also provide a voltage gain stage before the miller capacitor. Both multiplying circuits enable the size of the miller capacitor to be reduced resulting in valuable printed circuit board space savings.

Abstract: A multistage amplifier includes a first gain stage having a first input terminal and a first output terminal, and a second gain stage having a first input terminal. A first inter-stage resistive element is coupled in series to the first output terminal of the first gain stage and the first input terminal of the second gain stage to reduce the adverse affects of one gain stage on a previous gain stage. The multistage amplifier may also have a differential pair with a local feedback path for each transistor of the differential pair. Such local feedback helps to stabilize an imaginary component of the input impedance of the differential amplifier. Such stabilization also helps to reduce the adverse affects one gain stage may have on a previous gain stage.

Abstract: An analog to digital converter (ADC) includes a cross switch array coupled between an input switch array and an integrator configured to alternately transfer charges from a first input capacitor and a second input capacitor to a first integration capacitor and a second integration capacitor thereby improving linearity problems caused by capacitor mismatching. The cross switch array may also be configured to transfer charges from the first input capacitor to the first integration capacitor and from the second input capacitor to the second integration capacitor during a first charge transfer time interval, and from the first input capacitor to the second integration capacitor and from the second input capacitor to the first integration capacitor during a second charge transfer time interval. A sensing system including and ADC consistent with the invention is also provided. Various methods of transferring charges in an ADC are also provided.

Abstract: A programmable after-package, on-chip reference voltage trim circuit for an integrated circuit having a plurality of programmable trim cells generating a programmed sequence. A converter is provided to convert the bit sequence into a trim current. The trim current is added to an initial value of a reference voltage to be trimmed, as generated by the integrated circuit. Once the correct value of the trim current is determined, isolation circuitry is programmed to isolate the trim circuitry from the remainder of the IC, thereby freeing the logic and package pins associated with the IC for use by users of the IC. The preferred trim circuitry includes fuses which are blown in accordance with a bit value supplied to the trim cell to permanently fix a trim current value, once a best fit value is determined.