摘要:
Various apparatuses, methods and systems for switched mode electronic circuits with reduced EMI are disclosed herein. For example, some embodiments of the present invention provide apparatuses including a power supply, an output, and a composite switch connected between the power supply and the output. The composite switch includes a plurality of transistors connected in parallel, a switch closing delay line having a plurality of switch closing outputs each connected to a control input of one of the plurality of transistors, and a switch opening delay line having a plurality of switch opening outputs each connected to one of the plurality of switch closing outputs. The switch closing delay line and switch opening delay line are connected in an order that opens the plurality of transistors in a staggered order in time and closes the plurality of transistors in a reverse staggered order in time.
摘要:
The present invention provides an apparatus and method for operating driver amplifier (20) of a line driver circuit (10) from a lower set of power supply voltages, and from a higher set of voltages only when the amplitude of the signal (12) being transmitted by the line driver (20) requires it as determined by a comparator (18). Advantageously, this reduces the power dissipation in the line driver (10) by operating the line amplifier (20) the majority of the time from the lower supply voltage. A delay circuit (14) delays the signal to be amplified sufficient to allow the transitioning of the power supply voltages provided to the amplifier hysteresis of this power supply voltage switching may also be used to further reduce power dissipation.
摘要:
Series strings of photovoltaic (PV) modules with integrated dc-dc microconverters that can function in buck, boost, or an intermediate bridge mode based on the load can harvest more energy than conventional central-inverter architectures, especially when the arrays are partially shaded or when the modules are mismatched. The integrated multi-mode dc-dc converter includes a maximum power point tracking (MPPT) algorithm that can track the true MPP, even when a PV module becomes partially-shaded, without scanning the entire output voltage range. The algorithm compares power levels only at a voltage that occurs when a bypass diode bypasses a portion of an associated PV module, and multiples thereof.
摘要:
Series strings of photovoltaic (PV) modules with integrated dc-dc microconverters that can function in buck, boost, or an intermediate bridge mode based on the load can harvest more energy than conventional central-inverter architectures, especially when the arrays are partially shaded or when the modules are mismatched. The integrated multi-mode dc-dc converter includes a maximum power point tracking (MPPT) algorithm that can track the true MPP, even when a PV module becomes partially-shaded, without scanning the entire output voltage range. The algorithm compares power levels only at a voltage that occurs when a bypass diode bypasses a portion of an associated PV module, and multiples thereof.
摘要:
A low-EMI switched circuit comprises two or more switches, wherein impedance transitions of the switches are overlapped and the overlap is varied using variable switch timing based on an output power level of the switched circuit. The variable timing results in a variable impedance overlap between the switches. In one example, when one switch turns off (begins a low to high impedance transition) and a second switch turns on (begins a high to low impedance transition), a greater timing delay in beginning the second switch's transition results in a higher switch impedance overlap than a shorter delay does. If the variable timing is based on output power of the switched circuit, the variable delay can operate to reduce fly-back voltages at high power output levels and reduce shoot-through current at lower power levels, reducing EMI and quiescent current of the switched circuit.
摘要:
Systems and methods for reduced distortion in a class D amplifier are provided. An “ideal” digital output signal is produced. The “ideal” digital output signal is then compared to the actual output signal in an error amplifier. The integrator input is the difference between the output stage waveform and the ideal output stage waveform. The net input to the integrator now comprises the imperfections of the power stage, and the feedback loop drives their average to zero. This error is then amplified and integrated. The integrated signal is than applied to a summer where it is added to the analog input. Then as in the typical Class D amplifier, the integrated signal is compared in an error amplifier to a ramp signal generated from the ramp generator.
摘要:
Methods and apparatus for an analog-to-digital converter (ADC) with reduced comparator-hysteresis effects. One embodiment uses a charge-redistribution ADC. One method performs an initial coarse analog-to-digital conversion to avoid overdriving an analog voltage comparator. One such method includes a redundant capacitor in an array of charge-redistribution capacitors used in the ADC for sample-and-hold and successive-approximation functions. Another method performs a traditional initial successive-approximation analog-to-digital conversion, and then performs an additional conversion-step test based on the least-significant bit of the initial result to correct for comparator errors in the initial conversion.
摘要:
Systems and methods for reduced distortion in a class D amplifier are provided. An “ideal” digital output signal is produced. The “ideal” digital output signal is then compared to the actual output signal in an error amplifier. The integrator input is the difference between the output stage waveform and the ideal output stage waveform. The net input to the integrator now comprises the imperfections of the power stage, and the feedback loop drives their average to zero. This error is then amplified and integrated. The integrated signal is than applied to a summer where it is added to the analog input. Then as in the typical Class D amplifier, the integrated signal is compared in an error amplifier to a ramp signal generated from the ramp generator.
摘要:
A low-EMI switched circuit comprises two or more switches, wherein impedance transitions of the switches are overlapped and the overlap is varied using variable switch timing based on an output power level of the switched circuit. The variable timing results in a variable impedance overlap between the switches. In one example, when one switch turns off (begins a low to high impedance transition) and a second switch turns on (begins a high to low impedance transition), a greater timing delay in beginning the second switch's transition results in a higher switch impedance overlap than a shorter delay does. If the variable timing is based on output power of the switched circuit, the variable delay can operate to reduce fly-back voltages at high power output levels and reduce shoot-through current at lower power levels, reducing EMI and quiescent current of the switched circuit.
摘要:
Various apparatuses, methods and systems for switched mode electronic circuits with reduced EMI are disclosed herein. For example, some embodiments of the present invention provide apparatuses including a power supply, an output, and a composite switch connected between the power supply and the output. The composite switch includes a plurality of transistors connected in parallel, a switch closing delay line having a plurality of switch closing outputs each connected to a control input of one of the plurality of transistors, and a switch opening delay line having a plurality of switch opening outputs each connected to one of the plurality of switch closing outputs. The switch closing delay line and switch opening delay line are connected in an order that opens the plurality of transistors in a staggered order in time and closes the plurality of transistors in a reverse staggered order in time.