Abstract: Methods and systems of reducing a substrate noise in a charge pump having a flying capacitor are provided. An input node of the flying capacitor is pre-charged at a first slew rate. The input node of the flying capacitor is charged at a second slew rate that is faster than the first slew rate. The input node of the flying capacitor is pre-discharged at a third slew rate. The input node of the flying capacitor is discharged at a fourth slew rate that is faster than the first slew rate.

Abstract: Methods and systems of reducing a substrate noise in a charge pump having a flying capacitor are provided. An input node of the flying capacitor is pre-charged at a first slew rate. The input node of the flying capacitor is charged at a second slew rate that is faster than the first slew rate. The input node of the flying capacitor is pre-discharged at a third slew rate. The input node of the flying capacitor is discharged at a fourth slew rate that is faster than the first slew rate.

Abstract: In accordance with an embodiment of the present invention, a bandgap voltage reference circuit includes a group of X current sources, a plurality of circuit branches, and a plurality of switches. Each of the X current sources (where X?3) produces a corresponding current that is substantially equal to the currents produced by the other current sources within the group. The plurality of circuit branches of the bandgap voltage reference circuit are collectively used to produce a bandgap voltage output (VGO). Each of the plurality of circuit branches receives at least one of the currents not received by the other circuit branches. The plurality of switches (e.g., controlled by a controller) selectively change over time which of the currents produced by the current sources are received by which of the plurality of circuit branches of the bandgap voltage reference circuit.

Abstract: In accordance with an embodiment of the present invention, a bandgap voltage reference circuit includes a plurality of circuit branches, a plurality of resistors and a plurality of switches. The plurality of switches are used to selectively change over time which of the resistors are connected to be within a first one of the circuit branches and which of the resistors are connected to be within a second one of the circuit branches, to thereby reduce the effects that long term drift of the resistors have on a bandgap voltage output (VGO) of the bandgap voltage reference circuit.

Abstract: An RF-coupled digital isolator includes a first leadframe portion and a second leadframe portion, electrically isolated from one another. The first leadframe portion includes a first main body and a first finger. The second leadframe portion includes a second main body and a second finger. The first main body is connected to a first ground, and the second main body is connected to a second ground that is electrically isolated from the first ground. The first finger and the second finger are electrically isolated from one another, e.g., by a plastic molding compound that forms a package for the digital isolator. The first finger acts as a primary of a transformer, and the second finger acts as a secondary of a transformer, when an RF signal drives to the first finger. The first finger and the second finger can be substantially parallel or anti-parallel to one another.

Abstract: In accordance with an embodiment of the present invention, a bandgap voltage reference circuit includes a plurality of circuit branches, a plurality of resistors and a plurality of switches. The plurality of switches are used to selectively change over time which of the resistors are connected to be within a first one of the circuit branches and which of the resistors are connected to be within a second one of the circuit branches, to thereby reduce the effects that long term drift of the resistors have on a bandgap voltage output (VGO) of the bandgap voltage reference circuit.

Abstract: In accordance with an embodiment of the present invention, a bandgap voltage reference circuit includes a group of X current sources, a plurality of circuit branches, and a plurality of switches. Each of the X current sources (where X?3) produces a corresponding current that is substantially equal to the currents produced by the other current sources within the group. The plurality of circuit branches of the bandgap voltage reference circuit are collectively used to produce a bandgap voltage output (VGO). Each of the plurality of circuit branches receives at least one of the currents not received by the other circuit branches. The plurality of switches (e.g., controlled by a controller) selectively change over time which of the currents produced by the current sources are received by which of the plurality of circuit branches of the bandgap voltage reference circuit.

Abstract: An apparatus and method for controlling the operation of a utility device, such as a cold cathode fluorescent lamp that is powered in accordance with a pulse width modulation (PWM) signal, includes an analog sensor which monitors the utility device to derive an output signal representative of the PWM signal. An integrating analog-to-digital converter (ADC), which is coupled to the sensor and has its operation synchronized with an integral multiple of the period of the PWM signal, produces an output representative of an average of the output of the utility device.

Abstract: Ground skimming output stages that are designed to drive wideband signals with the ability to provide a high quality output signal all the way to the low supply rail are provided. In accordance with an embodiment of the present invention, the output stage of the present invention includes a translinear current controller, an output transistor and a current mirror. While not limited thereto, embodiments of the present invention only require a single positive power supply, consistent with the recent trend toward integrated circuits that only require a single low voltage power supply.

Abstract: Provided herein are circuits and methods to generate a voltage proportional to absolute temperature (VPTAT) and/or a bandgap voltage output (VGO). A circuit includes a group of X transistors. A first subgroup of the X transistors are used to produce a first base-emitter voltage (VBE1). A second subgroup of the X transistors are used to produce a second base-emitter voltage (VBE2). The VPTAT can be produced by determining a difference between VBE1 and VBE2. Which of the X transistors are in the first subgroup and used to produce the first base-emitter voltage (VBE1), and/or which of the X transistors are in the second subgroup and used to produce the second base-emitter voltage (VBE2), change over time. Additionally, a circuit portion can be used to generates a voltage complimentary to absolute temperature (VCTAT) using at least one of the X transistors. The VPTAT and the VCTAT can be added to produce the VGO.

Abstract: A bandgap voltage reference circuit includes a first circuit portion and a second circuit portion. The first circuit portion generates a voltage complimentary to absolute temperature (VCTAT). The second circuit portion generates a voltage proportional to absolute temperature (VPTAT) that is added to the VCTAT to produce a bandgap voltage reference output. The first circuit portion includes a plurality of delta base-emitter voltage (VBE) generators, connected as a plurality of stacks of delta VBE generators. Each delta VBE generator can include a pair of transistors that operate at different current densities and thereby generate a difference in base-emitter voltages (?VBE). The plurality of delta VBE generators within each stack are connected to one another, and the plurality of stacks of delta VBE generators are connected to one another, such that the ?VBEs generated by the plurality of delta VBE generators are arithmetically added to produce the VPTAT.

Abstract: A video synchronization signal generating circuit includes a sample and hold circuit, a voltage divider and an amplifier. The voltage divider produces an adaptive voltage level based at least in part on an output of the sample and hold circuit. The amplifier, which receives a video signal, is connectable by switches in different configurations. In a first configuration the amplifier acts as a comparator to compare the adaptive voltage level with the video signal. An output of the amplifier in the first configuration is an output of the video synchronization signal generating circuit. In a second configuration the amplifier forms part of the sample and hold circuit.

Abstract: An apparatus and method for controlling the operation of a utility device, such as a cold cathode fluorescent lamp that is powered in accordance with a pulse width modulation (PWM) signal, includes an analog sensor which monitors the utility device to derive an output signal representative of the PWM signal. An integrating analog-to-digital converter (ADC), which is coupled to the sensor and has its operation synchronized with an integral multiple of the period of the PWM signal, produces an output representative of an average of the output of the utility device.

Abstract: Provided herein are input stages, and operation amplifiers including input stages. In an embodiment, an input stage includes a complimentary differential input transconductor, first and second npn-pnp current mirrors, and first and second pnp-npn current mirrors. The complimentary differential input transconductor includes a pair of differential inputs that accept a pair of voltage signals, a first pair of complimentary differential outputs that output current signals I1 and I2, and a second pair of complimentary differential outputs that output current signals I3 and I4. Each current mirror accepts one of the current signals I1, I2, I3 and I4, and outputs a pair of current signals (e.g., I1? and I1?) that are proportional to the accepted current signal (e.g., I1). Current signals I1? and I3? are added to produce a first output current (Iout) of the input stage. Current signals I2? and I4? are added to produce a second output current (Iout_bar) of the input stage.

Abstract: A bandgap voltage reference circuit includes a first circuit portion and a second circuit portion. The first circuit portion generates a voltage complimentary to absolute temperature (VCTAT). The second circuit portion generates a voltage proportional to absolute temperature (VPTAT) that is added to the VCTAT to produce a bandgap voltage reference output. The first circuit portion includes a plurality of delta base-emitter voltage (VBE) generators, connected as a plurality of stacks of delta VBE generators. Each delta VBE generator can include a pair of transistors that operate at different current densities and thereby generate a difference in base-emitter voltages (?VBE). The plurality of delta VBE generators within each stack are connected to one another, and the plurality of stacks of delta VBE generators are connected to one another, such that the ?VBEs generated by the plurality of delta VBE generators are arithmetically added to produce the VPTAT.

Abstract: An embodiment of an amplifier includes an amplifier output node operable to provide an output signal, and an output stage. The output stage includes a drive buffer having an input node and an output node, a drive transistor, and a compensation capacitor. The drive transistor has a control node coupled to the output node of the drive buffer, a first drive node, and a second drive node coupled to the amplifier output node. And the compensation capacitor has a first node isolated from the control node of the drive transistor by the drive buffer, and has a second node coupled to the amplifier output node. By buffering the control node of the drive transistor, one may reduce the level of nonlinear current referred back to the amplifier input as a nonlinear offset voltage, and thus may reduce the level of nonlinear distortion that his nonlinear offset voltage generates at the amplifier output.

Abstract: An apparatus and method for controlling the operation of a utility device, such as a cold cathode fluorescent lamp that is powered in accordance with a pulse width modulation (PWM) signal, includes an analog sensor which monitors the utility device to derive an output signal representative of the PWM signal. An integrating analog-to-digital converter (ADC), which is coupled to the sensor and has its operation synchronized with an integral multiple of the period of the PWM signal, produces an output representative of an average of the output of the utility device.

Abstract: Provided herein are input stages, and operation amplifiers including input stages. In an embodiment, an input stage includes a complimentary differential input transconductor, first and second npn-pnp current mirrors, and first and second pnp-npn current mirrors. The complimentary differential input transconductor includes a pair of differential inputs that accept a pair of voltage signals, a first pair of complimentary differential outputs that output current signals I1 and I2, and a second pair of complimentary differential outputs that output current signals I3 and I4. Each current mirror accepts one of the current signals I1, I2, I3 and I4, and outputs a pair of current signals (e.g., I1? and I1?) that are proportional to the accepted current signal (e.g., I1). Current signals I1? and I3? are added to produce a first output current (Iout) of the input stage. Current signals I2? and I4? are added to produce a second output current (Iout bar) of the input stage.

Abstract: Ground skimming output stages that are designed to drive wideband signals with the ability to provide a high quality output signal all the way to the low supply rail are provided. In accordance with an embodiment of the present invention, the output stage of the present invention includes a translinear current controller, an output transistor and a current mirror. While not limited thereto, embodiments of the present invention only require a single positive power supply, consistent with the recent trend toward integrated circuits that only require a single low voltage power supply.

Abstract: An RF-coupled digital isolator includes a first leadframe portion and a second leadframe portion, electrically isolated from one another. The first leadframe portion includes a first main body and a first finger. The second leadframe portion includes a second main body and a second finger. The first main body is connected to a first ground, and the second main body is connected to a second ground that is electrically isolated from the first ground. The first finger and the second finger are electrically isolated from one another, e.g., by a plastic molding compound that forms a package for the digital isolator. The first finger acts as a primary of a transformer, and the second finger acts as a secondary of a transformer, when an RF signal drives to the first finger. The first finger and the second finger can be substantially parallel or anti-parallel to one another.