摘要:
A DC to DC buck pulse width modulator converter circuit includes an input, a high side output and a low side output. A high side switch is electrically connected between a common output node and a voltage supply, and controls a flow of current therethrough dependent upon the high side output. A low side switch is electrically connected between the common output node and ground, and controls a flow of current therethrough dependent upon the low side output. A virtual ground amplifier includes a second input electrically connected to ground. A current feedback resistor is electrically connected intermediate the common output node and a first input of the virtual ground amplifier. A variable impedance component is electrically connected to an output of the virtual ground amplifier and to the first input of the virtual ground amplifier. The impedance of the variable impedance component is varied dependent upon the output of the virtual ground amplifier. A sample and hold circuit is electrically connected intermediate the input of the pulse width modulator converter circuit and the variable impedance component. The sample and hold circuit sources a virtual ground current through the variable impedance component, and samples the virtual ground current.
摘要:
A D/A converter including first and second R-R2 resistor ladders and a set of SPDT switches. The first R-2R resistor ladder includes N type resistors coupled between a common voltage node and an output voltage node and the second R-2R resistor ladder includes P type resistors coupled between the common and output voltage nodes. The R-2R resistor ladders have multiple common switch terminals, each coupling an N type 2R resistor to a corresponding P type 2R resistor. Each SPDT switch is responsive to a data bit for switching a common switch terminal between the common voltage and a reference voltage. Each N type resistor may be formed in a PWell coupled to the common (or more negative) voltage and each P type resistor may be formed in an NWell coupled to the reference (or more positive) voltage. The SPDT switches may be configured with equivalent switch path impedances.
摘要:
A multi-phase DC/DC converter having an output voltage and including a plurality of converter channels. Each converter channel includes a converter channel input and a converter channel output. Each converter channel is configured for generating a converter channel current and for adjusting said converter channel current in response to a control signal electrically connected to each converter channel input. A control circuit generates an error signal representative of a comparison of the converter output voltage to a reference voltage. The control circuit includes a plurality of control circuit channels, each of which correspond to a converter channel. Each control circuit channel generates a channel current signal representative of a corresponding converter channel current, and generates a differential channel current signal representative of a comparison of the channel current signal to an average current signal. The average current signal is representative of an overall average current for the converter channels. Each control circuit channel generates a differential error signal representative of a comparison of the error signal to the differential channel current signal. Each control circuit channel includes a pulse width modulator having a ramp input and a control input. The control input is electrically connected to the differential error signal. The pulse width modulator generates the control signal based upon the differential error signal. The control signal is electrically coupled to a corresponding converter channel input. The control circuit generates the average current signal.
摘要:
A DC to DC buck pulse width modulator converter circuit includes an input, a high side output and a low side output. A high side switch is electrically connected between a common output node and a voltage supply, and controls a flow of current therethrough dependent upon the high side output. A low side switch is electrically connected between the common output node and ground, and controls a flow of current therethrough dependent upon the low side output. A virtual ground amplifier includes a second input electrically connected to ground. A current feedback resistor is electrically connected intermediate the common output node and a first input of the virtual ground amplifier. A variable impedance component is electrically connected to an output of the virtual ground amplifier and to the first input of the virtual ground amplifier. The impedance of the variable impedance component is varied dependent upon the output of the virtual ground amplifier. A sample and hold circuit is electrically connected intermediate the input of the pulse width modulator converter circuit and the variable impedance component. The sample and hold circuit sources a virtual ground current through the variable impedance component, and samples the virtual ground current.
摘要:
A set of series connected power supplies are progressively connected to a load as the voltage to the load increases. Starting with a first voltage power supply, as the load voltage increases at or to the first voltage level, a switch connects the next successive power supply in series with the first power supply and to the load. As the load voltage increases progressively approaching each successively connected power supply in the set of series connected power supplies, the load is switched to the next series connected power supply increasing the voltage and current available to the load. As the load voltage decreases progressively from the highest series connected voltage to the voltage of the next lower series connected power supply voltage, the load is switched to that next lower series connected power supply. In operation, a first power supply is connected in series to a plurality of power supplies. A switch connects the first power supply to a load. As the voltage of that load increases reaching the first power supply level, the switch connects in the next series connected power supply to the load increasing the voltage and the current available to the load. As the voltage increases at the load to the voltage level of the next series connected power supply, the next series connected power supply is switched to the load increasing the voltage and the current available to the load. This switching process continues till the highest voltage level of the series connected power supplies is reached by the load. As the voltage at the load decreases, falling through each next decreasing level, from each successively lower power supply is disconnected.
摘要:
A variable impedance element which is utilized to shunt a signal and control the amplitude of the signal utilizes a P-MOS and an N-MOS transistor operated in parallel. Separate control voltages are applied to each device in a direction to lower the impedance of the device with an increase in the peak to peak voltage of the input signal. Thus, by controlling each of the separate shunted transistors from separate peak detectors and according to the polarity of the signal voltage, each transistor will operate somewhat independent from the other to therefore provide accurate gain control and a symmetrical impedance variation.
摘要:
An apparatus for sensing an input current through an inductor includes an RC circuit connected in parallel with the inductor across first and second input pins of an integrated circuit. A voltage monitoring circuit monitors a first voltage at the first input pin of the integrated circuit and monitors a second voltage at the second input pin of the integrated circuit. An op-amp compares the first voltage with the second voltage and generates a control output responsive to the comparison. A current sink circuit responsive to the indication controls the first voltage to substantially equal the second voltage.
摘要:
A DC/DC converter has an output voltage and sources an output current to a load. The DC/DC converter includes an error amplifier with a reference input and a summing input. The reference input is electrically connected to a reference voltage. The summing input is electrically connected to the output voltage and the output current. The summing input is configured for adding together the output voltage and the output current. The error amplifier issues an error signal and adjusts the error signal dependent at least in part upon the output voltage and the output current. A comparator receives the error signal. The comparator has a ramp input electrically connected to a voltage ramp signal. The comparator issues an output signal that is based at least in part upon said error input. A power switch has an on condition and an off condition, and supplies dc current to the load when in the on condition. The power switch has a control input electrically connected to the comparator output signal. The power switch is responsive to the control input to change between the on condition and the off condition to thereby adjust the output current of the DC/DC converter.
摘要:
A DC to DC buck pulse width modulator converter circuit includes an input, a high side output and a low side output. A high side switch is electrically connected between a common output node and a voltage supply, and controls a flow of current therethrough dependent upon the high side output. A low side switch is electrically connected between the common output node and ground, and controls a flow of current therethrough dependent upon the low side output. A virtual ground amplifier includes a second input electrically connected to ground. A current feedback resistor is electrically connected intermediate the common output node and a first input of the virtual ground amplifier. A variable impedance component is electrically connected to an output of the virtual ground amplifier and to the first input of the virtual ground amplifier. The impedance of the variable impedance component is varied dependent upon the output of the virtual ground amplifier. A sample and hold circuit is electrically connected intermediate the input of the pulse width modulator converter circuit and the variable impedance component. The sample and hold circuit sources a virtual ground current through the variable impedance component, and samples the virtual ground current.
摘要:
A user-programmable bi-directional, constant current generator circuit allows external programming of either a positive (+) or a negative (−) polarity output current, for injection into one of two locations of the PWM controller circuit of a DC-DC voltage converter. The parameters of the DC-DC converter's offset voltage will depend upon the connection of a single programming pin to one of two programming resistors. The programming resistors are respectively referenced to different supply rail voltages (VCC and VSS). The polarity of the offset additionally depends upon where, within the PWM-controlled DC-DC converter, the programmed constant current is injected.