METHOD AND APPARATUS FOR DIGITAL CONTROL OF A SWITCHING REGULATOR
Granted: August 30, 2012
Application Number:
20120218788
In one aspect, a power supply includes an energy transfer element, a switch, a feedback circuit, a comparator, a state machine, and a control circuit. The feedback circuit generates a feedback signal representative of an output level of the power supply. The comparator provides a feedback state signal having a first feedback state that represents the output level of the power supply being above a threshold level and a second feedback state that represents the output level being below the…
METHOD AND APPARATUS FOR IMPLEMENTING AN UNREGULATED DORMANT MODE WITH AN EVENT COUNTER IN A POWER CONVERTER
Granted: August 30, 2012
Application Number:
20120218786
An example power converter includes an energy transfer element, a switch, and a control circuit. The control circuit includes a drive signal generator and an unregulated dormant mode control circuit. The unregulated dormant mode control circuit renders dormant the drive signal generator thereby ceasing the regulation of the output by the drive signal generator when the energy requirement of the one or more loads falls below a threshold for more than a first period of time. The drive…
FAULT CONDITION PROTECTION
Granted: August 16, 2012
Application Number:
20120206842
A switched mode power supply includes a transformer and an integrated circuit regulator. The integrated circuit regulator is coupled to the transformer and includes switching regulator logic, a counter, and a switching transistor. The regulator logic generates a switching signal in response to the feedback signal. The counter receives the feedback signal, where the feedback signal periodically cycles between a first state and a second state when the switched mode power supply operates…
Integrated Transistor and Anti-Fuse Programming Element for a High-Voltage Integrated Circuit
Granted: August 9, 2012
Application Number:
20120199885
A semiconductor device includes an N type well region in a P type substrate. A source region of a MOSFET is laterally separated from a boundary of the well region, which includes the drain of the MOSFET. An insulated gate of the MOSFET extends laterally from the source region to at least just past the boundary of the well region. A polysilicon layer, which forms a first plate of a capacitive anti-fuse, is insulated from an area of the well region, which forms the second plate of the…
METHOD AND APPARATUS FOR INCREASING THE POWER CAPABILITY OF A POWER SUPPLY
Granted: July 26, 2012
Application Number:
20120188799
One example controller for a power supply includes an oscillator, a drive signal generator, and a restart circuit. The oscillator generates a clock signal and the drive signal generator controls switching of a switch to regulate an output of the power supply in response to the clock signal. The restart circuit generates a restart signal in response to a current through the switch and in response to an absolute maximum on time period. The oscillator generates the clock signal to have a…
ASYMMETRIC SWITCH FORWARD CONVERTER
Granted: July 26, 2012
Application Number:
20120188800
A switching circuit for use in a power supply includes a first active switch coupled to a first terminal of a primary winding of a transformer. A second active switch is coupled to a second terminal of the primary winding of the transformer. An output capacitance of the first active switch is greater than an output capacitance of the second active switch. A first passive switch is coupled to the second active switch and to the second terminal of the primary winding. A second passive…
APPARATUS AND METHOD FOR DETECTING A CHANGE IN OUTPUT VOLTAGE OF AN ISOLATED POWER CONVERTER
Granted: July 5, 2012
Application Number:
20120170327
An output voltage sensor for use in a power converter controller includes a first pulse sampler circuit coupled to receive a feedback signal representative of an output of a power converter. The first pulse sampler circuit is coupled to capture a first peak voltage representative of a second peak of a ringing voltage of the feedback signal at a first time in the feedback signal. A second pulse sampler circuit is coupled to receive the feedback signal representative of the output of the…
METHOD AND APPARATUS FOR IMPLEMENTING AN UNREGULATED DORMANT MODE IN A POWER CONVERTER
Granted: July 5, 2012
Application Number:
20120170329
A control circuit includes a drive signal generator controlling switching of a power switch to regulate a flow of energy to one or more loads coupled to a power converter output. A regulator circuit charges a capacitor to a first voltage and stops charging the capacitor if an energy requirement of the one or more loads falls below a threshold. The regulator again charges the capacitor after the capacitor is discharged from the first voltage to a second voltage. An unregulated dormant…
METHOD AND APPARATUS FOR A POWER SUPPLY CONTROLLER RESPONSIVE TO A FEEDFORWARD SIGNAL
Granted: June 28, 2012
Application Number:
20120163041
An example power supply controller includes a switch duty cycle controller coupled to receive a feedback signal and a duty cycle adjust signal. The switch duty cycle controller is coupled to generate a drive signal coupled to control switching of a switch, which is coupled to an energy transfer element, to regulate energy delivered from an input of a power supply to an output of the power supply. The power supply controller also includes a gain selector circuit coupled to receive an…
METHOD AND APPARATUS TO REGULATE AN OUTPUT VOLTAGE OF A POWER CONVERTER AT LIGHT/NO LOAD CONDITIONS
Granted: June 28, 2012
Application Number:
20120163043
An example controller for a primary side control power converter includes a feedback circuit, a driver circuit, and an adjustable voltage reference circuit. The feedback circuit is coupled to compare a feedback signal representative of a bias winding voltage of the power converter with a voltage reference. The driver circuit is coupled to output a switching signal to control a switch of the power converter to regulate an output of the power converter in response the feedback circuit. The…
METHOD AND APPARATUS FOR TIME-DIFFERENTIAL COMPARISON OF AN ANALOG SIGNAL
Granted: June 28, 2012
Application Number:
20120161815
A time-differential analog comparator is disclosed. An example apparatus according to aspects of the present invention includes a source of a variable frequency signal having a frequency responsive to an analog input. A counting circuit is coupled to count cycles of the variable frequency signal. The counting circuit is coupled to count in a first direction for a first time interval and is coupled to count in a second direction opposite to the first direction for a second time interval…
VARIABLE TIME CLAMP FOR A POWER SUPPLY CONTROLLER
Granted: June 28, 2012
Application Number:
20120161739
An example integrated circuit for use in a power supply includes a feedback terminal and a controller having a variable time clamp (VTC). The feedback terminal is to be coupled to receive a feedback signal and the controller is to be coupled to enable or disable the conduction of a power switch during a switching cycle in response to the feedback signal. The controller includes a current limit comparator coupled to terminate the conduction of the power switch during an enabled switching…
METHOD AND APPARATUS FOR ADJUSTING DISPLACEMENT CURRENT IN AN ENERGY TRANSFER ELEMENT
Granted: June 21, 2012
Application Number:
20120151749
Example methods include calculating a first number of turns of a shield winding included in an energy transfer element of a power supply. A first number of turns of the shield winding is calculated for the power supply to have a low noise current in an input conductor of the power supply. The method then includes increasing the first number of turns to a second number of turns. The power supply is then operated, which generates a first voltage waveform of a voltage between the input…
METHOD AND APPARATUS TO LIMIT OUTPUT POWER IN A SWITCHING POWER SUPPLY
Granted: June 21, 2012
Application Number:
20120155129
An example power supply includes an energy transfer element, a switch, and a controller. The controller includes a modulator, a drive signal generator, a comparator, and a variable current limit generator. The modulator generates an enable signal having logic states responsive to a feedback signal. The drive signal generator either enables or skips enabling a switch of the power supply during a switching period in response to the logic state of the enable signal. The comparator asserts…
High-voltage transistor device with integrated resistor
Granted: June 14, 2012
Application Number:
20120146105
A high-voltage device structure comprises a resistor coupled to a tap transistor that includes a JFET in a configuration wherein a voltage provided at a terminal of the JFET is substantially proportional to an external voltage when the external voltage is less than a pinch-off voltage of the JFET. The voltage provided at the terminal being substantially constant when the external voltage is greater than the pinch-off voltage. One end of the resistor is substantially at the external…
ELECTRONIC CIRCUIT CONTROL ELEMENT WITH TAP ELEMENT
Granted: June 14, 2012
Application Number:
20120146141
A technique for controlling a power supply with power supply control element with a tap element. An example power supply control element includes a power transistor that has first and second main terminals, a control terminal and a tap terminal. A control circuit is coupled to the control terminal. The tap terminal and the second main terminal of the power transistor are to control switching of the power transistor. The tap terminal is coupled to provide a signal to the control circuit…
METHOD AND APPARATUS FOR INPUT CHARGE CONTROL OF A POWER SUPPLY
Granted: June 14, 2012
Application Number:
20120146607
An example power supply includes an energy transfer element, a switch and a controller. The controller includes a logic circuit and a constant current control circuit. The logic circuit generates a drive signal to control the switch in response to a control signal. The constant current control circuit generates the control signal in response to a received input current sense signal, input voltage sense signal, and output voltage sense signal. An integrator included in the constant…
Temperature Independent Reference Circuit
Granted: June 14, 2012
Application Number:
20120146715
A temperature independent reference circuit includes first and second bipolar transistors with commonly coupled bases. First and second resistors are coupled in series between the emitter of the second bipolar transistor and ground. The first and second resistors have first and second resistance values, R1 and R2, and third and second temperature coefficients, TC3 and TC2, respectively. The resistance values being such that a temperature coefficient of a difference between the…
APPARATUS AND METHOD FOR SENSING OF ISOLATED OUTPUT
Granted: June 14, 2012
Application Number:
20120147632
A controller for use in a power converter includes a control circuit to be coupled to a current controller coupled to an energy transfer element. A first, second or third current is enabled in the current controller in response to the control circuit. The first current is substantially zero, the second current is greater than the third current, and the third current is greater than the first current. The third current only partially discharges a capacitance coupled to a terminal coupled…
METHOD AND APPARATUS FOR CONTROLLING A CIRCUIT WITH A HIGH VOLTAGE SENSE DEVICE
Granted: June 7, 2012
Application Number:
20120139012
A high-voltage junction field-effect transistor (JFET) includes a semiconductor substrate, a well region, first, second, and third doped regions, and first, second, and third terminals. The first doped region is disposed in the well region and the second dope region is laterally displaced from the well region. The third doped region is disposed in the well region between the first and second doped regions. A portion of the well region is substantially depleted of free charge carriers…
