Patent application number | Description | Published |
20090072755 | LIGHT-EMITTING SEMICONDUCTOR DEVICE DRIVER AND METHOD - An electronic device includes circuitry for driving a light-emitting diode (LED) or other light-emitting semiconductor device. The circuitry includes a first switch (NM | 03-19-2009 |
20090167264 | DC-DC CONVERTER USABLE FOR DUAL VOLTAGE SUPPLY - A converter has a single inductor with a first terminal connectable to a first terminal of the supply input through a first power transistor and a second terminal connectable to a second terminal of the supply input through a second power transistor. A first rectifier element connects the first terminal of the inductor with a first output terminal, and a second rectifier element connects the second terminal of the inductor with a second output terminal. A resistive voltage divider is connected between the first and second output terminals. A control circuit uses an input from the voltage divider as a reference input voltage and provides an output current to the second terminal of the supply input in response to any voltage difference between the reference input voltage and the second terminal of the supply input. This provides a virtual common reference potential at the second terminal of the supply input, which is thus a common ground (GND) terminal. In the ON phase of both power transistors, the inductor is charged with current from the supply input. In the OFF phase (both power transistors are OFF), the energy stored in the inductor is supplied to both of the positive and the negative supply output through the rectifier elements, the output current in fact flowing almost exclusively between the positive and negative supply outputs. Thus, in the OFF phase, the inductor is entirely isolated from the supply input and the supply outputs are in no way affected by any transients or fluctuations in the supply input voltage. | 07-02-2009 |
20110050250 | ELECTRONIC DEVICE AND METHOD FOR INDUCTOR CURRENT MEASUREMENT - An electronic device includes a circuit for measuring a current in an inductor, wherein the current in the inductor is controlled by alternately switching a first power transistor and a second power transistor each having a first electrode, a second electrode and a control gate. The measuring circuit includes a first sense transistor having a first electrode, a second electrode and a control gate, the first sense transistor having the control gate coupled to the control gate of the first power transistor. A second electrode is coupled to the second electrode of the first power transistor. A second sense transistor has a first electrode, a second electrode and a control gate, the second sense transistor having the control gate coupled to the control gate of the second power transistor and having the second electrode coupled to the second electrode of the second power transistor. An amplifier is operable in a first configuration for providing an output current that is a function of a first current though the first sense transistor during a first period of time or in a second configuration for providing the output current as a function of a second current through the second sense transistor during a second period of time, so as to alternately sense a current through the first power transistor with the first sense transistor and through the second power transistor with the second sense transistor. | 03-03-2011 |
20110068754 | ELECTRONIC DEVICE AND METHOD FOR DC-DC CONVERSION - An electronic device for DC-DC conversion of an input voltage into an output voltage is provided. The electronic device includes a current mode control loop for controlling a sensed current of the DC-DC conversion by comparing a voltage level indicating a magnitude of the sensed current with a reference voltage level indicating the maximum admissible magnitude of the sensed current. The reference voltage level is dynamically adjusted in response to a change of an input voltage level. | 03-24-2011 |
20130320949 | ELECTRONIC DEVICE FOR AVERAGE CURRENT MODE DC-DC CONVERSION - An average current mode buck-boost DC to DC converter has a buck stage coupled between an input voltage source terminal and an output terminal. A boost stage is coupled between the input voltage source terminal and the output terminal. A current ramp control circuit generates a ramp signal for driving the buck and boost stages, the ramp signals being coupled to the buck and boost stages. A constant voltage related to the desired output voltage by a constant is applied directly to both a voltage control feedback loop for adjusting the output voltage and directly to an input to the current ramp control circuit, whereby the output voltage can be shifted from one voltage to another by feedforward control. | 12-05-2013 |
20150054478 | ELECTRONIC DEVICE FOR AVERAGE CURRENT MODE DC-DC CONVERSION - An average current mode buck-boost DC to DC converter has a buck stage coupled between an input voltage source terminal and an output terminal. A boost stage is coupled between the input voltage source terminal and the output terminal. A current ramp control circuit generates a ramp signal for driving the buck and boost stages, the ramp signals being coupled to the buck and boost stages. A constant voltage related to the desired output voltage by a constant is applied directly to both a voltage control feedback loop for adjusting the output voltage and directly to an input to the current ramp control circuit, whereby the output voltage can be shifted from one voltage to another by feedforward control. | 02-26-2015 |