Abstract: An integrated control circuit according to aspects of the present invention includes an oscillator, a capacitor, and a logic gate. The oscillator generates a periodic timing signal that cycles between a first logic state for a first time duration and a second logic state for a second time duration. The capacitor receives a charge current in response to the periodic timing signal transitioning to the first logic state, where a voltage on the capacitor increases for the first time duration to an initial value. The logic gate generates a periodic output signal having a duty ratio that is responsive to a time that it takes the capacitor to discharge from the initial value to a reference voltage. A period of the periodic output signal is the period of the periodic timing signal.

Abstract: An example controller for a power supply includes a drive signal generator and a compensation circuit. The drive signal generator is to be coupled to control switching of a switch included in the power supply to regulate an output voltage of the power supply in response to a sensed output voltage such that the output voltage of the power supply is greater than an input voltage of the power supply. The compensation circuit is coupled to the drive signal generator and is also coupled to output an offset current to adjust the sensed output voltage in response to the input voltage of the power supply.

Abstract: An example power supply controller includes a regulation circuit, a current sense circuit, and a response circuit. The regulation circuit is coupled to regulate a sense terminal to a voltage level. The current sense circuit is coupled to the sense terminal to sense a current through the sense terminal a measurement delay period after a magnitude of the current through the sense terminal reaches a first threshold current level. The response circuit is coupled to the sense circuit and is responsive to the current through the sense terminal only after the measurement delay period.

Abstract: An integrated control circuit according to aspects of the present invention includes a capacitor to develop a first current during a first time duration in response to a charge current and to develop a second voltage during a second time duration in response to a discharge current. A comparator is also included and is coupled to the capacitor to indicate when the voltage on the capacitor reaches the second voltage. A control logic sets a duty ratio of a periodic output signal in response to the time it takes the capacitor to discharge from the first voltage to the second voltage. An oscillator is coupled to provide a timing signal to the control logic. In one aspect, the control logic includes an output that is coupled to the oscillator to change a frequency of the oscillator.

Abstract: 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 input voltage signal, which is representative of an input voltage to the power supply, to generate the duty cycle adjust signal received by the switch duty cycle controller. The duty cycle of the drive signal to be varied in response to a plurality of linear functions over a range of values of the input voltage signal.

Abstract: A sample and hold circuit with leakage compensation is disclosed. An example sample and hold circuit includes a first switch coupled to sample and hold an input signal value in a first capacitor coupled to the first switch in response to a sample signal. A second switch through which a second leakage current flows to a second capacitor coupled to the second switch is also included. The second leakage current through the second switch to the second capacitor is substantially equal to a first leakage current through the first switch to the first capacitor. An offset circuit that is coupled to the first and second capacitors is also included to produce a compensated sampled value in response to a difference between a quantity representing the held input signal value and charge accumulated in the first capacitor in response to the first leakage current from a quantity representing charge accumulated in the second capacitor in response to the second leakage current.

Abstract: An integrated control circuit according to aspects of the present invention includes a capacitor to develop a first current during a first time duration in response to a charge current and to develop a second voltage during a second time duration in response to a discharge current. A comparator is also included and is coupled to the capacitor to indicate when the voltage on the capacitor reaches the second voltage. A control logic sets a duty ratio of a periodic output signal in response to the time it takes the capacitor to discharge from the first voltage to the second voltage. An oscillator is coupled to provide a timing signal to the control logic. In one aspect, the control logic includes an output that is coupled to the oscillator to change a frequency of the oscillator.

Abstract: An apparatus and method of switching a switch of a power supply in response to an input voltage signal are disclosed. According to aspects of the present invention, a 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 input voltage signal, which is representative of an input voltage to the power supply, to generate the duty cycle adjust signal received by the switch duty cycle controller. The maximum duty cycle of the drive signal to be varied in response to a plurality of linear functions over a range of values of the input voltage signal.

Abstract: An apparatus and method of providing a pulse width modulated signal that is responsive to a current are disclosed. A circuit according to aspects of the present invention includes a capacitor to convert a first current to a first voltage on the capacitor during a first time duration and to discharge a second current from the capacitor to change the first voltage to a second voltage during a second time duration. A comparator is also included and is coupled to an output of the capacitor to compare a voltage on the capacitor to a reference voltage during the second time duration to change a pulse width of a periodic output signal in response to an input current.

Abstract: An example power supply controller includes a regulation circuit, a current sense circuit, and a response circuit. The regulation circuit is coupled to regulate a sense terminal to a voltage level. The current sense circuit is coupled to the sense terminal to sense a current through the sense terminal a measurement delay period after a magnitude of the current through the sense terminal reaches a first threshold current level. The response circuit is coupled to the sense circuit and is responsive to the current through the sense terminal only after the measurement delay period.

Abstract: An example power supply includes a controller and a detection circuit. The controller includes a sense terminal coupled to provide a sense terminal current representative of an input voltage of the power supply during normal operation. The detection circuit is external to the controller and is coupled to the sense terminal. The detection circuit includes a Zener diode coupled to conduct a current to adjust the sense terminal current during a fault condition, where during the fault condition the controller is responsive to a measured impedance of the detection circuit which is determined in response to the sense terminal current.

Abstract: An apparatus and method of providing a pulse width modulated signal that is responsive to a current are disclosed. A circuit according to aspects of the present invention includes a capacitor to convert a first current to a first voltage on the capacitor during a first time duration and to discharge a second current from the capacitor to change the first voltage to a second voltage during a second time duration. A comparator is also included and is coupled to an output of the capacitor to compare a voltage on the capacitor to a reference voltage during the second time duration to change a pulse width of a periodic output signal in response to an input current.

Abstract: An example controller for a power supply includes a drive signal generator and a compensation circuit. The drive signal generator is to be coupled to control switching of a switch included in the power supply to regulate an output voltage of the power supply in response to a sensed output voltage such that the output voltage of the power supply is greater than an input voltage of the power supply. The compensation circuit is coupled to the drive signal generator and is also coupled to output an offset current to adjust the sensed output voltage in response to the input voltage of the power supply.

Abstract: An apparatus and method of providing a pulse width modulated signal that is responsive to a current are disclosed. A circuit according to aspects of the present invention includes a capacitor to convert a first current to a first voltage on the capacitor during a first time duration and to discharge a second current from the capacitor to change the first voltage to a second voltage during a second time duration. A comparator is also included and is coupled to an output of the capacitor to compare a voltage on the capacitor to a reference voltage during the second time duration to change a pulse width of a periodic output signal in response to an input current.

Abstract: A method is disclosed to add functionality to a terminal of a high voltage integrated circuit without the penalty of additional high voltage circuitry. The benefit is that alternative modes of operation can be selected for testing, trimming parameters of the integrated circuit, or any other purpose without the cost of an additional terminal. In one embodiment, ordinary low voltage circuitry monitors the voltage on the terminal that normally is exposed to high voltage. The configuration of a simple voltage detector and an ordinary latch allows easy entry into the test and trimming mode when the integrated circuit is not in the intended application, but prohibits entry into the test and trimming mode when the integrated circuit operates in the intended application.

Abstract: A sample and hold circuit with leakage compensation is disclosed. An example sample and hold circuit includes a first switch coupled to sample and hold an input signal value in a first capacitor coupled to the first switch in response to a sample signal. A second switch through which a second leakage current flows to a second capacitor coupled to the second switch is also included. The second leakage current through the second switch to the second capacitor is substantially equal to a first leakage current through the first switch to the first capacitor. An offset circuit that is coupled to the first and second capacitors is also included to produce a compensated sampled value in response to a difference between a quantity representing the held input signal value and charge accumulated in the first capacitor in response to the first leakage current from a quantity representing charge accumulated in the second capacitor in response to the second leakage current.

Abstract: A sample and hold circuit in one aspect includes first and second switches. The first switch can be coupled to receive an input signal and to sample the input signal using a first capacitor. A first leakage current flows between first and second conductive terminals of the first switch and accumulates as a first leakage charge in the first capacitor. A second leakage current flows between the first and second conductive terminals of the second switch and accumulates as a second leakage charge in the second capacitor. An offset circuit produces a compensated sampled value by subtracting a quantity from a signal developed in response to the held sampled signal and charge accumulated through the first switch, wherein the quantity is developed in response to the accumulated leakage charge in the second capacitor.

Abstract: A sample and hold circuit in one aspect includes first and second switches. The first switch can be coupled to receive an input signal and to sample the input signal using a first capacitor. A first leakage current flows between first and second conductive terminals of the first switch and accumulates as a first leakage charge in the first capacitor. A second leakage current flows between the first and second conductive terminals of the second switch and accumulates as a second leakage charge in the second capacitor. An offset circuit produces a compensated sampled value by subtracting a quantity from a signal developed in response to the held sampled signal and charge accumulated through the first switch, wherein the quantity is developed in response to the accumulated leakage charge in the second capacitor.

Abstract: An apparatus and method of providing a pulse width modulated signal that is responsive to a current are disclosed. A circuit according to aspects of the present invention includes a capacitor to convert a first current to a first voltage on the capacitor during a first time duration and to discharge a second current from the capacitor to change the first voltage to a second voltage during a second time duration. A comparator is also included and is coupled to an output of the capacitor to compare a voltage on the capacitor to a reference voltage during the second time duration to change a pulse width of a periodic output signal in response to an input current.

Abstract: An apparatus and method of providing a pulse width modulated signal that is responsive to a current are disclosed. A circuit according to aspects of the present invention includes a capacitor to convert a first current to a first voltage on the capacitor during a first time duration and to discharge a second current from the capacitor to change the first voltage to a second voltage during a second time duration. A comparator is also included and is coupled to an output of the capacitor to compare a voltage on the capacitor to a reference voltage during the second time duration to change a pulse width of a periodic output signal in response to an input current.