Patent application number | Description | Published |
20080197812 | Topology and method for dynamic charging current allocation - In one embodiment, a battery management system includes a charger controller for controlling a charging current of a battery according to a status of a load which is powered by the battery, and a counter coupled to the charger controller for determining a charging time according to such status. Advantageously, a first charging current is selected when the load is off. A second charging current that is less than the first charging current is selected when the load is on. Furthermore, a frequency of the counter is set to a first frequency when the load is off. The frequency is set to a second frequency that is less than the first frequency when the load is on. | 08-21-2008 |
20090066161 | Power management systems with current sensors - A power management system includes a power management unit (PMU) and a current sensor. The PMU is operable for controlling a first power source and a second power source. The second power source is operable for being charged by the first power source via a charging path. The current sensor has a first terminal coupled to the first power source and the second power source and has a second terminal coupled to the second power source via the charging path. The current sensor is operable for sensing a first current flowing from the first power source through the current sensor and for sensing a second current flowing from the second power source through the current sensor. | 03-12-2009 |
20100320979 | CURRENT CONTROL SYSTEMS WITH CURRENT FEEDBACKS - A current control system includes a first switch, a second switch, and a controller. The second switch is coupled in parallel with the first switch and operable for providing a feedback signal indicative of a current flowing through the first switch. The feedback signal is determined by a width-to-length ratio of the first switch and a width-to-length ratio of the second switch. In addition, the controller is coupled to the first and second switches and operable for adjusting the current according to the feedback signal. | 12-23-2010 |
20100327658 | SYSTEM FOR MANAGING POWER BASED ON CURRENT MONITORING - A system includes a power bus and a circuit. The power bus delivers power from a first power source to an output node. The circuit monitors a current flowing through the power bus and provides power from a second power source to the output node based on an amount of the current, and maintains a voltage level of the output node in a predetermined range. | 12-30-2010 |
20110285321 | LIGHT SOURCE DRIVING CIRCUIT WITH LOW OPERATING OUTPUT VOLTAGE - A driving circuit for regulating current in a light source using a tracking component. The tracking component detects the voltage difference between an input node in the input stage and an output node in the output stage. The input stage is connected to a current source and includes an input transistor. The output stage is connected to the light source and includes an output transistor. The tracking component generates an output that controls the input and output transistors based on the voltage difference between the input node and the output node so that the voltage at the input node tracks the voltage at the output node. By using the tracking component, the LED driver can achieve accurate current control through one output transistor instead of cascaded transistors, resulting in lower output operating voltage and reduced power dissipation of the LED driver. Further, the tracking component is intermittently operated or shared across different channels to reduce energy consumption of the LED driver. | 11-24-2011 |
20120206430 | CIRCUITS FOR ELIMINATING GHOSTING PHENOMENA IN DISPLAY PANEL HAVING LIGHT EMITTERS - The present disclosure provides a circuit for discharging parasitic capacitance in a display panel with common-anode topology having a plurality of light emitters, as well as a circuit for charging parasitic capacitance in a display panel with common-cathode topology. In the common-cathode topology, the circuit includes a three-terminal device having a gate, a source, and a drain, wherein one of the source and the drain is electrically coupled to a common cathode of the light emitters, and a mechanism for controlling the three-terminal device, the mechanism being electrically coupled to the gate. Shortly after a previously selected light emitter is unselected, the mechanism turns on the three-terminal device to form a conductive path between the source and the drain. The mechanism turns off the three-terminal device after a voltage at the common cathode is increased to a predetermined voltage level or after a maximum period of time lapses. | 08-16-2012 |
20120327128 | LED DISPLAY SYSTEMS - An LED display system comprises an LED array and an LED driver circuit. An LED driver circuit comprises components including a phase lock loop, a pulse width modulation engine, a configuration register, a gain adjustable fast charge current source, and a serial input/output interface. The components in this driver circuit may be integrated on a same chip. The LED array may be arranged in a common cathode configuration. | 12-27-2012 |
20120327129 | LED DISPLAY SYSTEMS - An LED display system comprises an LED array and an LED driver circuit. An LED driver circuit comprises components including a phase lock loop, a pulse width modulation engine, a configuration register, a series of gain adjustable fast charge current sources, and a serial input/output interface. The components in this driver circuit may be integrated on a same chip. The LED array may be arranged in a common cathode configuration. | 12-27-2012 |
20130140998 | CIRCUITRY AND METHOD FOR DRIVING LED DISPLAY - This disclosure provides a circuit and a method for driving an LED display. The driving circuit comprises a selection circuit for selecting a first light emitter from the plurality of light emitters, a pre-charging circuit for charging an equivalent capacitor of the display panel with respect to the selected first light emitter, and a power circuit for supplying power to the first light emitter after the first light emitter is selected, wherein the power circuit is configured to supply a driving current to the first light emitter in one or more stages. The driving circuit and method of this disclosure can be used to significantly increase the refresh rate and resolution of the LED display. | 06-06-2013 |