Abstract: A touch screen driver that can be used with a resistive touch screen includes an input/output module that supplies at least one input signal to at least one of a plurality of input/output ports of the touch screen and that generates at least one output signal, in response to the at least one input signal, and in accordance with at least one control signal. A controller module generates the at least one control signal and that generates a position signal representing a resolved position in accordance with a plurality of contemporaneous touches of the resistive touch screen.

Abstract: A universal serial bus on-the-go (USB-OTG) power source includes a direct-current to direct-current (DC-to-DC) converter for generating a source voltage when coupled to a battery. A pulse generator generates an oscillating signal when a USB-OTG enable signal is asserted. A power supply module generates a supply voltage from the oscillating signal and the source voltage.

Abstract: An embodiment of a system on a chip includes a reference clock circuit configured to produce a reference clock signal, a first clock circuit configured to produce a first clock signal, and adjustment circuitry. The adjustment circuitry is configured to make a determination of whether a characteristic of the reference clock signal compares unfavorably with a characteristic of the first clock signal, and when the characteristic of the reference clock signal compares unfavorably with the characteristic of the first clock signal, to adjust a parameter of the first clock circuit that results in tuning the first clock signal.

Abstract: A system on a chip includes a processing module, ROM, RAM, and a clocking circuit. The clock circuit is coupled to produce a first clock signal when the SOC is in a low power mode and to produce a second clock signal when the SOC is in a performance mode, where the first clock signal is less accurate than the second clock signal. The clock circuit consumes more power when producing the second clock signal than when producing the first clock signal.

Abstract: A handheld audio system includes a radio signal decoder integrated circuit (IC) and a digital audio processing integrated circuit. The radio signal decoder integrated circuit produces a digital left channel signal and a digital right channel signal from a received radio signal in accordance with an enable signal and also produces a system clock. The digital audio processing integrated circuit includes a DC-to-DC converter and a processing module. The DC-to-DC converter is operably coupled to produce at least one power supply voltage based on the system clock. The processing module is operably coupled to produce the enable signal when the at least one power supply voltage has reached a desired level and to produce audio signals for audio playback from at least one of the digital left and right channel signals and a stored digital audio file.

Abstract: A system on a chip includes a real time clock (RTC) module, a crystal oscillation circuit and a voltage supply circuit. The RTC module is coupled to provide timing functions and the crystal oscillation circuit is coupled to produce an oscillation. The voltage supply circuit is coupled to produce a supply voltage for at least a portion of the RTC module and the crystal oscillation circuit. The voltage supply circuit includes: a reference circuit coupled to produce a reference voltage based on the supply voltage; a transistor coupled to the battery IC pin, wherein the transistor produces the supply voltage based on a regulation signal and the battery voltage; an amplifier coupled to produce the regulation signal based on the reference voltage and a feedback representation of the supply voltage; and a start-up circuit coupled to enable the voltage supply circuit at battery connection.

Abstract: A system-on-a-chip integrated circuit includes a multimedia module that produces rendered output data and a high-speed interface. A processing module generates output multimedia data in accordance with at least a portion of a multimedia application in response to input multimedia data received from either the multimedia module or the high-speed interface. The output multimedia data is provided to either the multimedia module or the high-speed interface. An on-chip DC-to-DC converter converts a battery voltage into a supply voltage that is coupled to the multimedia module, the high-speed interface, and/or the processing module.

Abstract: A method for mitigating interference from a switched-mode power supply begins by comparing a channel of interest of a plurality of channels with a switching rate of a switch-mode power supply. The method continues when the channel of interest compares unfavorably to the switching rate by adjusting the switching rate of the switch-mode power supply until the channel of interest compares favorably to the switching rate.

Abstract: A method for regulating a DC to DC converter of a portable device begins by sensing deactivation of a non-battery power source of the portable device, wherein an internal supply voltage is derived from the non-battery power source. The method continues by obtaining an initial regulation value for the DC to DC converter, wherein the initial regulation value is based on a battery voltage and the internal supply voltage. The method continues by enabling the DC to DC converter based on the initial regulation value, wherein the DC to DC converter converts the battery voltage into the internal supply voltage such that transitioning from the non-battery power source to a battery power source provides the substantially constant internal supply voltage.

Abstract: A digital to analog converter (DAC) includes at least one digital to analog conversion module and a gated termination. The at least one digital to analog conversion module is coupled to convert at least one bit of a digital signal into an analog signal. The gated termination is coupled to an analog output of the at least one digital to analog conversion module to provide a first termination when a termination selection signal is in a first state and to provide a second termination when the termination selection signal is in a second state.

Abstract: An optimized battery usage circuit for a comprehensive system-on-a-chip includes a first DC-to-DC converter operable to convert a battery voltage into a supply voltage when an alternate power source is not coupled to the comprehensive system-on-a-chip. A second DC-to-DC converter is operable to convert an alternate power source voltage into the supply voltage when the alternate power source is coupled to the comprehensive system-on-a-chip.

Abstract: A circuit for use by a multifunction handheld device is coupleable to an audio output device, the multifunction handheld device including a color video display device and a host interface that is coupleable to a host device.

Abstract: A class-D amplifier includes a switching transistor section, a filter, an analog to digital converter, and a feedback module. The switching transistor section is operably coupled to convert a serial input into a switched output signal. The filter is operably coupled to filter the switched output signal to produce an output of the class-D amplifier. The analog to digital converter is operably coupled to convert an analog input into a multi-bit digital signal based on a feedback signal, wherein the serial input corresponds to the multi-bit digital signal. The feedback module is operably coupled to the produce the feedback signal based on at least one varying property of the switching transistor section.

Abstract: A touch screen driver that can be used with a resistive touch screen includes an input/output module that supplies at least one input signal to at least one of a plurality of input/output ports of the touch screen and that generates at least one output signal, in response to the at least one input signal, and in accordance with at least one control signal. A controller module generates the at least one control signal and that generates a position signal representing a resolved position in accordance with a plurality of contemporaneous touches of the resistive touch screen.

Abstract: A digital to analog converter (DAC) includes at least one digital to analog conversion module and a gated termination. The at least one digital to analog conversion module is coupled to convert at least one bit of a digital signal into an analog signal. The gated termination is coupled to an analog output of the at least one digital to analog conversion module to provide a first termination when a termination selection signal is in a first state and to provide a second termination when the termination selection signal is in a second state.

Abstract: A method and system to determine a battery mode of an integrated circuit device are presented. The battery mode is selected with respect to first and second direct current to direct current converter devices within the integrated circuit. A voltage is received at a single pin of the device. A battery mode is determined for the device based on the received voltage, and at least one of the direct current to direct current converter circuits is configured based on the determined battery mode.

Abstract: A processing system includes a direct current to direct current (DC-DC) converter for generating a supply voltage when coupled to a battery. A memory module stores a plurality of operational instructions. A processing module receives power from the DC-DC converter and executes the plurality of operational instructions. A power monitor circuit monitors the power source and powers down the power source when a first error condition is detected in the power source.

Abstract: A class-D amplifier includes a switching transistor section, a filter, an analog to digital converter, and a feedback module. The switching transistor section is operably coupled to convert a serial input into a switched output signal. The filter is operably coupled to filter the switched output signal to produce an output of the class-D amplifier. The analog to digital converter is operably coupled to convert an analog input into a multi-bit digital signal based on a feedback signal, wherein the serial input corresponds to the multi-bit digital signal. The feedback module is operably coupled to the produce the feedback signal based on at least one varying property of the switching transistor section.

Abstract: A power supply includes a switching circuit and a transient control module. The switching circuit is switched in accordance with a regulation signal to produce an output voltage. The adjustable feedback module is operably coupled to produce the regulation signal based on the output voltage. The transient control module adjusts the adjustable feedback module by a step adjust value to produce a present output voltage. The transient control module monitors the adjustable feedback module for a present adjustment to determine when the power supply substantially achieves a steady-state condition. When the power supply substantially achieves a steady-state condition, determining whether the present output voltage corresponds to the second output voltage level. When the present output voltage does not correspond to the second output voltage level, the adjust, the monitor, and the determine steps are repeated.

Abstract: A battery converter, which is used to convert battery voltage to an output voltage to power an integrated circuit in a battery-operated mode, is placed into a battery-charge mode to charge the battery when external power source is present to power the integrated circuit and the battery needs charging.