Patent application number | Description | Published |
20080259650 | Changing switching frequency of a primary side power converter to compensate for inductance variation - A comparing circuit and a control loop are used to maintain the peak level of current flowing through an inductor of a flyback converter. An inductor switch control signal controls a switch through which the inductor current flows. The inductor current increases at a ramp-up rate during a ramp time and stops increasing at the end of the ramp time. The comparing circuit generates a timing signal that indicates a target time at which the inductor current would reach a predetermined current limit if the inductor current continued to increase at the ramp-up rate. The control loop then receives the timing signal and compares the target time to the end of the ramp time. The pulse width of the inductor switch control signal is increased when the target time occurs after the end of the ramp time. Adjusting the frequency and pulse width controls the peak of the inductor current. | 10-23-2008 |
20080259651 | Constant current and voltage controller in a four-pin package with dual-use pin - A comparing circuit and a control loop are used to maintain the peak level of current flowing through an inductor of a flyback converter. An inductor switch control signal controls an inductor switch through which the inductor current flows. The inductor current increases at a ramp-up rate during a ramp time and stops increasing at the end of the ramp time. The comparing circuit generates a timing signal that indicates a target time at which the inductor current would reach a predetermined current limit if the inductor current continued to increase at the ramp-up rate. The control loop then receives the timing signal and compares the target time to the end of the ramp time. The pulse width of the inductor switch control signal is increased when the target time occurs after the end of the ramp time. Adjusting the pulse width controls the peak of the inductor current. | 10-23-2008 |
20080259652 | Compensating for base current in a primary side power converter that uses an NPN bipolar transistor - A comparing circuit and a control loop are used to maintain the peak level of current flowing through an inductor of a flyback converter. An inductor switch control signal controls a switch through which the inductor current flows. The inductor current increases at a ramp-up rate during a ramp time and stops increasing at the end of the ramp time. The comparing circuit generates a timing signal that indicates a target time at which the inductor current would reach a predetermined current limit if the inductor current continued to increase at the ramp-up rate. The control loop then receives the timing signal and compares the target time to the end of the ramp time. The pulse width of the inductor switch control signal is increased when the target time occurs after the end of the ramp time. Adjusting the frequency and pulse width controls the peak of the inductor current. | 10-23-2008 |
20080259654 | Compensating for cord resistance to maintain constant voltage at the end of a power converter cord - A cord correction circuit in a primary-side-controlled flyback converter compensates for the loss of output voltage caused by the resistance of the charger cord. In one embodiment, a correction voltage is subtracted from a feedback voltage received from a primary-side auxiliary inductor. A pre-amplifier then compares a reference voltage to the corrected feedback voltage. In another embodiment, the correction voltage is summed with the reference voltage, and the pre-amplifier compares the feedback voltage to the corrected reference voltage. The difference between the voltages on the input leads of the pre-amplifier is used to increase the output voltage to compensate for the voltage lost through the charger cord. The flyback converter also has a comparing circuit and a control loop that maintain the peak level of current flowing through the primary inductor of the converter. Adjusting the frequency and pulse width of an inductor switch signal controls the converter output current. | 10-23-2008 |
20080284408 | Sequential calibration of matched current sources - A system involves LED strings and programmable current source circuits (CSC). An LED current flows through each LED string. Each LED current is controlled by an associated programmable CSC. In one embodiment, the CSCs form a chain. A first CSC uses a reference current for calibration, and thereafter supplies the reference current to the next CSC. When the next CSC detects the reference current, it uses the reference current for calibration. CSCs are calibrated one by one down the chain. In a second embodiment, each CSC can receive the reference current from a common conductor. If the common conductor is detected to be available, then the CSC uses the reference current for calibration. When the conductor is in use, the other CSCs detect the conductor as unavailable and do not attempt to self-calibrate. The CSCs use the reference current one by one, but in an order that changes over time. | 11-20-2008 |
20090016086 | Secondary side constant voltage and constant current controller - A low-cost integrated circuit is used as a secondary side constant voltage and constant current controller. The integrated circuit has four terminals and two amplifier circuits. A first amplifier circuit is used to sense a voltage on a FB terminal and in response to cause a first current to flow through an OPTO terminal. A second amplifier circuit is used to sense a voltage between a SENSE terminal and a SOURCE terminal and in response to cause a second current to flow through the same OPTO terminal. The FB terminal is used for output voltage feedback and is also used to supply power onto the integrated circuit. The SOURCE terminal is used for output current feedback and is also used as power supply return for the integrated circuit. The cost of the integrated circuit is reduced by having only four terminals. | 01-15-2009 |
20090040793 | Start-up time reduction in switching regulators - A start-up time accelerator is described for a switch controller that controls turning on or off a switch in a switching regulator. The start-up time accelerator uses the switch as a current amplifier and provides the amplified current to a capacitor using a current amplification path. In one example, the capacitor provides the bias voltage to a switch controller for the switch. Providing an amplified current to the capacitor accelerates the rate at which the bias voltage increases and reduces the time until the bias voltage reaches the turn-on threshold voltage of the switch controller. After the turn-on threshold voltage of the switch controller is reached, a second path is enabled for current to and from the capacitor and the capacitor provides the bias voltage to the switch controller until a voltage from an output voltage terminal is sufficiently high to provide the bias voltage for the switch controller through an auxiliary winding of a transformer. | 02-12-2009 |
20090091953 | Compensating for inductance variation in a power converter using a dual-purpose feedback pin - A comparing circuit and a control loop are used to maintain the peak level of current flowing through an inductor of a flyback converter. An inductor switch control signal controls an inductor switch through which the inductor current flows. The inductor current increases at a ramp-up rate during a ramp time and stops increasing at the end of the ramp time. The comparing circuit generates a timing signal that indicates a target time at which the inductor current would reach a predetermined current limit if the inductor current continued to increase at the ramp-up rate. The control loop then receives the timing signal and compares the target time to the end of the ramp time. The pulse width of the inductor switch control signal is increased when the target time occurs after the end of the ramp time. Adjusting the pulse width controls the peak of the inductor current. | 04-09-2009 |
20090132987 | Method and system for the modular design and layout of integrated circuits - An integrated circuit (IC) and fabrication method thereof is provided that include the steps of specifying a plurality of required tile modules suitable for a particular end application, each of the modular tiles being configured to perform a predetermined function and constructed to have approximately the same length and width dimensions. The modular tiles are used to form the IC in a standard IC fabrication process. In many implementations, physical layout of the IC does not include the step of routing. Capabilities also include configuring the modular tiles to have programmable performance parameters and configuring the modular tiles to cooperate usefully with one another based on a programmable parameter. | 05-21-2009 |
20090207636 | Constant current and voltage controller in a small package with dual-use pin - A comparing circuit and a control loop are used to maintain the peak level of current flowing through an inductor of a flyback converter. An inductor switch control signal controls an inductor switch through which the inductor current flows. The inductor current increases at a ramp-up rate during a ramp time and stops increasing at the end of the ramp time. The comparing circuit generates a timing signal that indicates a target time at which the inductor current would reach a predetermined current limit if the inductor current continued to increase at the ramp-up rate. The control loop then receives the timing signal and compares the target time to the end of the ramp time. The pulse width of the inductor switch control signal is increased when the target time occurs after the end of the ramp time. Adjusting the pulse width controls the peak of the inductor current. | 08-20-2009 |
20090230550 | Method and system for the modular design and layout of integrated circuits - An integrated circuit (IC) and fabrication method thereof is provided that include the steps of specifying a plurality of required tile modules suitable for a particular end application, each of the modular tiles being configured to perform a predetermined function and constructed to have approximately the same length and width dimensions. The modular tiles are used to form the IC in a standard IC fabrication process. In many implementations, physical layout of the IC does not include the step of routing. Capabilities also include configuring the modular tiles to have programmable performance parameters and configuring the modular tiles to cooperate usefully with one another based on a programmable parameter. | 09-17-2009 |
20090284238 | Re-programmable modular power management circuit - An integrated circuit includes a buck converter controller, a PFET, an NFET that is coupled in common drain configuration to the PFET, a first microbump that is connected to the source of the PFET, a second microbump that is connected to the source of the NFET, a third microbump that is connected to the common drain node, a fourth microbump that is connected to a feedback input lead of the controller, and a plurality of other microbumps. | 11-19-2009 |
20090295348 | Constant current and voltage controller in a three-pin package with dual-use power pin - A flyback converter includes a controller integrated circuit (IC) housed in an IC package with only three terminals. An inexpensive TO-92 transistor package can be used. A switch terminal is coupled to an inductor switch that is turned on by a switch control signal having a frequency and a pulse width. The inductor switch controls the current that flows through a primary inductor of the flyback converter. The controller IC adjusts the frequency in a constant current mode such that output current remains constant and adjusts the pulse width in a constant voltage mode such that output voltage remains constant. A power terminal receives a feedback signal that is derived from a voltage across an auxiliary inductor of the flyback converter. The feedback signal provides power to the controller IC and is also used to generate the switch control signal. The controller IC is grounded through a ground terminal. | 12-03-2009 |
20090315165 | Method and system for the modular design and layout of integrated circuits - An integrated circuit (IC) and fabrication method thereof is provided that include the steps of specifying a plurality of required tile modules suitable for a particular end application, each of the modular tiles being configured to perform a predetermined function and constructed to have approximately the same length and width dimensions. The modular tiles are used to form the IC in a standard IC fabrication process. In many implementations, physical layout of the IC does not include the step of routing. Capabilities also include configuring the modular tiles to have programmable performance parameters and configuring the modular tiles to cooperate usefully with one another based on a programmable parameter. | 12-24-2009 |
20090319959 | Method and system for the modular design and layout of integrated circuits - An integrated circuit (IC) and fabrication method thereof is provided that include the steps of specifying a plurality of required tile modules suitable for a particular end application, each of the modular tiles being configured to perform a predetermined function and constructed to have approximately the same length and width dimensions. The modular tiles are used to form the IC in a standard IC fabrication process. In many implementations, physical layout of the IC does not include the step of routing. Capabilities also include configuring the modular tiles to have programmable performance parameters and configuring the modular tiles to cooperate usefully with one another based on a programmable parameter. | 12-24-2009 |
20090319975 | Method and system for the modular design and layout of integrated circuits - An integrated circuit (IC) and fabrication method thereof is provided that include the steps of specifying a plurality of required tile modules suitable for a particular end application, each of the modular tiles being configured to perform a predetermined function and constructed to have approximately the same length and width dimensions. The modular tiles are used to form the IC in a standard IC fabrication process. In many implementations, physical layout of the IC does not include the step of routing. Capabilities also include configuring the modular tiles to have programmable performance parameters and configuring the modular tiles to cooperate usefully with one another based on a programmable parameter. | 12-24-2009 |
20100002480 | Constant current and voltage controller in a three-pin package operating in critical conduction mode - A self-oscillating flyback converter includes a controller integrated circuit housed in a 3-pin package. A switch control terminal is coupled to the base of an inductor switch that controls the current through a primary inductor of the converter. The controller IC adjusts the on time of the switch such that output current remains constant in constant current mode and output voltage remains constant in constant voltage mode. A signal received on a switch control terminal turns the switch off and provides an indication of the output current when the switch is on. A signal received on a feedback terminal powers the controller IC and provides an indication of the output voltage when the switch is off. The controller IC is grounded through a ground terminal. The flyback converter transitions from critical conduction mode to discontinuous conduction mode at light loads to prevent its efficiency from deteriorating at high switching frequencies. | 01-07-2010 |
20110074352 | Compensating for cord resistance to maintain constant voltage at the end of a power converter cord - A cord correction circuit in a primary-side-controlled flyback converter compensates for the loss of output voltage caused by the resistance of the charger cord. In one embodiment, a correction voltage is subtracted from a feedback voltage received from a primary-side auxiliary inductor. A pre-amplifier then compares a reference voltage to the corrected feedback voltage. In another embodiment, the correction voltage is summed with the reference voltage, and the pre-amplifier compares the feedback voltage to the corrected reference voltage. The difference between the voltages on the input leads of the pre-amplifier is used to increase the output voltage to compensate for the voltage lost through the charger cord. The flyback converter also has a comparing circuit and a control loop that maintain the peak level of current flowing through the primary inductor of the converter. Adjusting the frequency and pulse width of an inductor switch signal controls the converter output current. | 03-31-2011 |