Patent application number | Description | Published |
20120081931 | METHOD AND APPARATUS TO CONTROL A POWER CONVERTER HAVING A LOW LOOP BANDWIDTH - An example controller includes a feedback sensor circuit that receives a feedback signal representative of an output of a power converter. A feedback sampling signal generator is coupled to generate a feedback sampling signal. The feedback sensor circuit samples the feedback signal in response to the feedback sampling signal. A state machine controls switching of a switch of a power converter circuit according to one of a plurality of operating condition states in response to the feedback sensor circuit. Each of the plurality of operating condition states includes a substantially fixed switch on time. A feedback time period signal generator generates a feedback time period signal received by the state machine. A period of the feedback time period signal is substantially greater than a period of the feedback sampling signal. The state machine is updated in response to the feedback time period signal. | 04-05-2012 |
20120320640 | METHOD AND APPARATUS FOR PROGRAMMING A POWER CONVERTER CONTROLLER WITH AN EXTERNAL PROGRAMMING TERMINAL HAVING MULTIPLE FUNCTIONS - A power converter controller is disclosed. An example controller includes a control circuit coupled to receive a feedback signal representative of an output of the power converter. The control circuit coupled to control a switching of a power switch of the power converter in response to the feedback signal to control a transfer of energy from an input of the power converter to the output of the power converter. An internal programming interface circuit is coupled to the control circuit. A coupling switcher is coupled to the internal programming interface circuit. An external programming terminal is selectively coupled to the internal programming interface circuit through the coupling switcher. An external programming circuit coupled to the external programming terminal is coupled to the internal programming interface circuit through the coupling switcher during a startup programming condition and during a fault condition of the power converter. The external programming circuit that is coupled to the external programming terminal is decoupled from the internal programming interface circuit by the coupling switcher during a normal operating condition of the power converter. | 12-20-2012 |
20130021828 | INTEGRATED ON-TIME EXTENSION FOR NON-DISSIPATIVE BLEEDING IN A POWER SUPPLY - An example controller for a switched mode power supply includes a comparator, a drive logic, and an on-time extension block. The comparator has an output indicating whether the current through a switch of the power supply exceeds a zero-crossing current threshold. The drive logic is to generate a drive logic output signal in response to the current sense signal and in response to a feedback signal, where the drive logic output signal is representative of an on-time of the switch to regulate the output of the power supply. The on-time extension block is coupled to control switching of a switch and to extend the on-time until the output of the comparator indicates that the current sense signal reaches the zero-crossing current threshold or until the on-time of the switch reaches a zero-crossing time threshold. | 01-24-2013 |
20130027815 | ADJACENT TERMINAL FAULT DETECTION - This relates to detecting unwanted couplings between a protected terminal and other terminals in an integrated controller of a power supply. Offset and clamp circuitry may apply a positive or negative offset voltage and clamp current to one or more terminals of the controller. In the event that a terminal having the offset voltage and clamp current is accidentally coupled to the protected terminal, the offset voltage and clamp current may be applied to the protected terminal. The protected terminal may be coupled to a fault detection circuitry operable to detect a fault signal at the protected terminal. The fault detection circuitry of the controller may cause the power supply to shut down in response to a detection of the fault signal at the protected terminal or may cause the power supply to shut down in response to a detection of a predefined threshold number of cycles in which the fault signal is detected. | 01-31-2013 |
20130027990 | VARYING SWITCHING FREQUENCY AND PERIOD OF A POWER SUPPLY CONTROLLER - An example integrated circuit controller for use in a switching power supply includes a pulse width modulation (PWM) circuit and a timing circuit. The PWM circuit controls a switch to regulate an output of the power supply in response to a switch current flowing through the switch and in response to a clock signal having a switching period. The timing circuit provides the clock signal and increases the switching period in response to an on time of the switch exceeding a threshold time. | 01-31-2013 |
20130027991 | METHOD AND APPARATUS TO CONTROL A POWER CONVERTER HAVING A LOW LOOP BANDWIDTH - An example controller includes a comparator coupled to receive a feedback signal representative of an output of the power converter. A counter is coupled to receive an output of the comparator and a feedback sampling signal. The counter is coupled to sample the output of the comparator in response to the feedback sampling signal. A state machine is coupled to receive a feedback time period signal. The state machine is coupled to control switching of the power converter according to one of a plurality of operating conditions in response to the counter and the feedback time period signal. A period of the feedback time period signal is substantially greater than a period of the feedback sampling signal. The state machine is coupled to be updated in response to the feedback time period signal. | 01-31-2013 |
20130077350 | POWER SUPPLY CONTROLLER WITH MINIMUM-SUM MULTI-CYCLE MODULATION - An example power supply controller includes a signal separator circuit that generates a feedback signal. An error signal generator generates an error signal in response to the feedback signal. A control circuit generates a drive signal in response to the error signal. The drive signal controls switching of a switch. A multi-cycle modulation circuit is included in the control circuit and generates a skip signal in response to a start skip signal, a stop skip signal and a skip mask signal. The skip mask signal is generated in response to the skip signal. The start skip and stop skip signals cause the drive signal to start skipping or stop skipping, respectively, on-time intervals of cycles. The skip mask signal disables the start skip signal from causing the drive signal to start skipping the on-time intervals of cycles. | 03-28-2013 |
20130077357 | ADAPTIVE BIASING FOR INTEGRATED CIRCUITS - Methods and apparatuses are disclosed for generating an adjustable bias current. The value of the adjustable bias current may be determined based in part on an error signal representative of a difference between an actual output value and a desired output value of a power converter. When the error signal is below a lower threshold voltage, the adjustable bias current may be set to a first value. When the error signal is above an upper threshold voltage, the adjustable bias current may be set to a second, higher value. When the error signal is between the lower threshold voltage and the upper threshold voltage, the adjustable bias current may change linearly with the error signal. | 03-28-2013 |
20130077358 | CONTROLLER WITH CONSTANT CURRENT LIMIT - Methods and apparatuses are disclosed for generating a temperature independent current limit. The value of the temperature independent current limit may be determined based in part on an error signal representative of a difference between an actual output value and a desired output value of a power converter. When the error signal is below a lower threshold voltage, the temperature independent current limit may be set to a first value. When the error signal is above an upper threshold voltage, the temperature independent current limit may be set to a second, higher value. When the error signal is between the lower threshold voltage and the upper threshold voltage, the temperature independent current limit may change linearly with the error signal. The error signal may be adjusted to compensate for changes in the system caused by a change in temperature. | 03-28-2013 |
20130083566 | MULTI-STAGE SAMPLING CIRCUIT FOR A POWER CONVERTER CONTROLLER - An example controller for a power converter includes a track and hold circuit, a sample and hold circuit, and drive logic. The track and hold circuit receives a signal from a terminal of the controller that is representative of an output voltage of the power converter. The track and hold circuit includes a first capacitor that provides a first voltage that tracks the signal and then holds the first voltage. The sample and hold circuit samples the first voltage when the first voltage is held on the first capacitor. The sample and hold circuit includes a second capacitor coupled to hold a second voltage representative of the first voltage after a sample period, where the second capacitor has a capacitance value larger than that of the first capacitor. The drive logic controls the first switch to regulate an output of the power converter in response to the second voltage. | 04-04-2013 |
20130100714 | POWER CONTROLLER WITH SMOOTH TRANSITION TO PULSE SKIPPING - A power converter control circuit includes a ramp signal circuit, a blanking circuit, and a pulse driver circuit. The ramp signal circuit provides a ramp signal in response to a power converter feedback signal and an enable signal. The blanking circuit provides a blanking signal in response to the ramp signal and a clock signal. The blanking signal is provided when both the ramp signal is increasing in value and the enable signal indicates a light load operating condition. The pulse driver circuit provides a power switch control pulse in accordance with the clock signal and in the absence of the blanking signal. | 04-25-2013 |
20130241440 | PHASE ANGLE MEASUREMENT OF A DIMMING CIRCUIT FOR A SWITCHING POWER SUPPLY - An example switched mode power supply includes a timer, a threshold adjust circuitry, a comparator, and a control circuitry. The timer times a duration between crossings of a phase-dimmed signal across a first threshold. The threshold adjust circuitry adjusts a second threshold representative of a desired output of the switched mode power supply, where the second threshold is adjusted responsive to the timed duration between crossings. The comparator compares a feedback signal with the second threshold and generates a comparison result. The control circuitry controls switching of a power switch responsive to the comparison result to regulate the output of the switched mode power supply. | 09-19-2013 |
20130250457 | ADJACENT TERMINAL FAULT DETECTION - This relates to detecting unwanted couplings between a protected terminal and other terminals in an integrated controller of a power supply. Offset and clamp circuitry may apply a positive or negative offset voltage and clamp current to one or more terminals of the controller. In the event that a terminal having the offset voltage and clamp current is accidentally coupled to the protected terminal, the offset voltage and clamp current may be applied to the protected terminal. The protected terminal may be coupled to a fault detection circuitry operable to detect a fault signal at the protected terminal. The fault detection circuitry of the controller may cause the power supply to shut down in response to a detection of the fault signal at the protected terminal or may cause the power supply to shut down in response to a detection of a predefined threshold number of cycles in which the fault signal is detected. | 09-26-2013 |
20130320882 | INTEGRATED ON-TIME EXTENSION FOR NON-DISSIPATIVE BLEEDING IN A POWER SUPPLY - An example controller for a switched mode power supply includes a zero crossing detector, drive logic, and a logic gate. The zero-crossing detector generates a zero-crossing signal indicating a zero-crossing condition in the power supply. The drive logic generates a drive logic output signal in response to the zero-crossing signal and in response to a feedback signal, where the drive logic output signal is representative of an on-time of a switch to regulate an output of the power supply. The logic gate is coupled to receive a first signal representative of a current through the switch and a second signal representative of a zero-crossing time threshold. The logic gate is further coupled to extend the on-time of the switch until current through the switch reaches a zero-crossing current threshold or until the on-time of the switch reaches the zero-crossing time threshold. | 12-05-2013 |
20130336019 | METHOD AND APPARATUS FOR DETERMINING ZERO-CROSSING OF AN AC INPUT VOLTAGE TO A POWER SUPPLY - An example controller for a power supply includes a first circuit and a drive signal generator. The first circuit receives a first signal representative of a switch current flowing through a switch of the power supply and then generates a second signal in response the switch current not reaching a current threshold within an amount of time. The second signal indicates when a dimming circuit at an input of the power supply is utilized. The drive signal generator generates a drive signal to control switching of the switch in response to the second signal, where energy is transferred across an energy transfer element of the power supply in response to the switching of the switch. | 12-19-2013 |
20140016377 | METHOD AND APPARATUS TO CONTROL A POWER CONVERTER HAVING A LOW LOOP BANDWIDTH - A controller for use in a power converter includes a comparator coupled to receive a signal representative of an output of the power converter. A counter is coupled to an output of the comparator to sample the output of the comparator a plurality of times within a period. A state machine is coupled to an output of the counter to control switching of the power converter according to one of a plurality of operating condition states in response to the output of the counter. The state machine is coupled to be updated at an end of the period. | 01-16-2014 |
20140049241 | DIMMING CONTROL FOR A SWITCHING POWER SUPPLY - An example controller includes a measurement block and a drive block. The measurement block determines an amount of time that a dimmer circuit, that is coupled to an input of a power supply, disconnects an ac input voltage. The drive block generates a drive signal to control switching of a switch included in the power supply. The drive block operates a closed loop dimming control when the amount of time is less than or equal to a threshold and operates an open loop dimming control when the amount of time is greater than the threshold. The closed loop dimming control includes setting one or more operating conditions of the drive signal in response to a feedback signal that is representative of an output quantity of the power supply. The open loop dimming control includes holding the one or more operating conditions of the drive signal to a value. | 02-20-2014 |
20140055293 | DIGITAL-TO-ANALOG CONVERTER TO PRODUCE PAIRED CONTROL SIGNALS IN A POWER SUPPLY CONTROLLER - An controller for use in a power supply includes a variable oscillator and a digital-to-analog converter (DAC). The variable oscillator generates a switching signal to control a first switch of the power supply to regulate an output current of the power supply. The variable oscillator sets a duration of an on-time of the switching signal to be inversely proportional to a magnitude of a first analog signal. The variable oscillator also sets a switching period of the switching signal to be inversely proportional to a magnitude of a second analog signal. The digital-to-analog converter (DAC) converts binary digits into the first and second analog signals, such that a sum of the magnitude of the first analog signal and the magnitude of the second analog signal is a fixed value. | 02-27-2014 |
20140063862 | VARYING SWITCHING FREQUENCY AND PERIOD OF A POWER SUPPLY CONTROLLER - A controller includes a PWM circuit and a timing circuit. The PWM circuit controls a switch in response to a clock signal. A switching period of the clock signal is based on a charging and discharging time of a capacitor included in the timing circuit. Both first and second current sinks discharge the capacitor while the timing circuit is in a normal discharging mode that is when an on time of the switch is less than a threshold time. The second current sink is prevented from discharging the capacitor such that the capacitor is discharged with the first current sink and not the second current sink while the timing circuit is in an alternative discharging mode that is when the on time of the switch exceeds the threshold time. The discharging of the capacitor in the alternative discharging mode increases the switching period of the clock signal. | 03-06-2014 |
20140098571 | SATURATION PREVENTION IN AN ENERGY TRANSFER ELEMENT OF A POWER CONVERTER - A controller for use in a power converter includes logic circuits to turn on and off a switch to regulate an output quantity. A first integrating capacitor is charged with a combination of a first current and a second current while the switch is turned on. The first current is proportional to a reset voltage and the second current is proportional to an input voltage. A reference generation circuit including a second integrating capacitor is charged with the first current during a previous switching cycle of the switch. The reference generation circuit generates a reference voltage in response to the second integrating capacitor. A comparator provides a stop signal to the logic circuits to turn off the switch in response to a comparison of a voltage across the first integrating capacitor with the reference voltage. | 04-10-2014 |
20140104887 | PROGRAMMING OF AN INTEGRATED CIRCUIT ON A MULTI-FUNCTION TERMINAL - Methods and apparatuses for programming a parameter value in an IC (e.g., any power electronic device, such as a controller of a power converter) are disclosed. The parameter can be selected/programmed by selecting a clamp using an external optional (selectively inserted) diode coupled to a multi-function programming terminal. In particular, a controller IC for a power converter can be externally programmed via one or more multiple function terminals during startup of the converter to select between two or more options using the external programming terminal(s). Once programming is complete, internal programming circuitry may be decoupled from the programming terminal and during normal operation the programming terminal may then be used for another function, such as a bypass (BP) terminal to provide a supply voltage to the IC or other required functionalities. | 04-17-2014 |
20140104895 | METHOD AND APPARATUS FOR PROGRAMMING A POWER CONVERTER CONTROLLER WITH AN EXTERNAL PROGRAMMING TERMINAL HAVING MULTIPLE FUNCTIONS - A power converter includes an energy transfer element and a power switch coupled the energy transfer element and an input of the power converter. A control circuit is coupled to generate a switching signal to control switching of the power switch in response to a feedback signal representative of an output of the power converter. A programming interface circuit is coupled to the control circuit and a coupling switcher coupled to the programming interface circuit. A programming terminal is selectively coupled to the programming interface circuit through the coupling switcher. A programming circuit coupled to the programming terminal is coupled to the programming interface circuit through the coupling switcher during a startup programming condition and during a fault condition of the power converter, and is decoupled from the programming interface circuit by the coupling switcher during a normal operating condition of the power converter. | 04-17-2014 |
20140119059 | SPLIT CURRENT MIRROR LINE SENSING - Apparatus and methods for filtering the transients of an input signal of an integrated circuit while maintaining a constant voltage at an input terminal of the integrated circuit are disclosed. In one example, the integrated circuit can be a controller of a switched-mode power supply. The controller can include a line sensing circuit coupled to receive an input signal representative of the line voltage and operable produce an output signal that can be used by other circuits within the controller. The input signal may include a current through a sense resistor coupled between the input of the power supply and the line sensing circuit. The output signal may include a scaled and filtered version of this current. The line sensing circuit can be coupled to the input terminal of the controller to receive the input signal or can directly receive the input signal. | 05-01-2014 |
20140204628 | MULTI-STAGE SAMPLING CIRCUIT FOR A POWER CONVERTER CONTROLLER - An example controller for a power converter includes a track and hold circuit, a sample and hold circuit, and drive logic. The track and hold circuit receives a signal that is representative of an output voltage of the power converter. The track and hold circuit includes a first capacitor that provides a first voltage that tracks the signal and then holds the first voltage. The sample and hold circuit then samples the first voltage that is held on the first capacitor. The sample and hold circuit includes a second capacitor that holds a second voltage representative of the first voltage after a fixed sample period. The second capacitor is larger than that of the first capacitor. The drive logic controlling the first switch to regulate the output of the power converter includes disabling the first switch during an on time of the first switch responsive to the second voltage. | 07-24-2014 |
20140233274 | POWER SUPPLY CONTROLLER WITH MINIMUM-SUM MULTI-CYCLE MODULATION - An example power supply controller includes a signal separator circuit that generates a feedback signal. An error signal generator generates an error signal in response to the feedback signal. A control circuit generates a drive signal in response to the error signal. The drive signal controls switching of a switch. A multi-cycle modulation circuit is included in the control circuit and generates a skip signal in response to a start skip signal, a stop skip signal and a skip mask signal. The skip mask signal is generated in response to the skip signal. The start skip and stop skip signals cause the drive signal to start skipping or stop skipping, respectively, on-time intervals of cycles. The skip mask signal disables the start skip signal from causing the drive signal to start skipping the on-time intervals of cycles. | 08-21-2014 |
20140340945 | POWER CONTROLLER WITH PULSE SKIPPING - A controller for a power converter includes a drive circuit coupled to generate a drive signal in response to an error signal representative of a load of the power converter. The drive circuit includes a pulse skipping circuit coupled to generate a blanking signal in response to the error signal. The pulse skipping circuit includes an enable circuit and a blanking circuit. The enable circuit is coupled to output an enable signal in response to the error signal. The blanking circuit is coupled to output the blanking signal in response to the enable signal and a ramp signal. The ramp signal is generated in response to the error signal. A duration of the blanking signal corresponds to a length of time for the ramp signal to reach a reference signal. The length of time is responsive to the error signal. | 11-20-2014 |