Abstract: A system includes multiple protection modules. Each protection module includes monitoring terminals that monitor battery cells' status, an output terminal that outputs a protection signal if an abnormal condition in the cells is detected, a switching terminal that receives a switching signal, and detection circuitry that switches from a normal-working mode to a fast-test mode if receiving the switching signal, delays outputting the protection signal for a first time interval if the abnormal condition is detected in the normal-working mode, and delays outputting the protection signal for a second time interval, less than the first time interval, if the abnormal condition is detected in the fast-test mode. In the protection modules, the switching terminal of a first protection module and a monitoring terminal of the first protection module are coupled to a second protection module and receive a protection signal from the output terminal of the second protection module.

Abstract: A circuit for driving a light source includes a power converter coupled between a power source and the light source, and a controller coupled to the power converter. The power converter receives power from the power source and provides a regulated power to the light source. The controller receives a conduction status signal indicating a conduction state of a dimmer coupled between the power source and the power converter, and adjusts the brightness of the light source based on the conduction status signal. The controller also receives an operation indicating signal indicative of operation of an ON/OFF switch coupled to the dimmer, and adjusts color temperature of the light source based on the operation indicating signal.

Abstract: A switching power supply includes a power converter which includes a transformer and a switch, a current sensor, a switch controller and a compensation resistor. The current sensor is operable for generating a current monitoring signal indicating a current through a primary winding of the transformer. The switch controller is operable for receiving a feedback signal indicating an output voltage of the power converter, generating a driving signal based on the feedback signal to control an input power and an output power of the transformer, receiving a line voltage signal indicating an input voltage of the power converter, and generating a compensation current corresponding to a peak value of the line voltage signal. The compensation resistor is coupled between the current sensor and the switch controller. A voltage of the current monitoring signal is inversely proportional to the input voltage under control of the compensation current and the compensation resistor.

Abstract: A light source driving circuit for powering a first light source and a second light source by a DC voltage includes a first control circuitry and a second control circuitry. If the DC voltage is within a first range, then the first control circuitry controls a first switch and the second control circuitry controls a second switch to turn on the first light source and to regulate a current flowing through the first light source. If the DC voltage is within a second range, then the first control circuitry controls a third switch and the second control circuitry controls a fourth switch to turn on the first light source and the second light source and to regulate a current flowing through the first light source and the second light source.

Abstract: A driving circuit includes a power converter, a dimming controller and a current path coupled to the dimming controller. The power converter receives input power from a rectifier and provides output power to a light source. A power switch transfers power from an AC power source to the rectifier when the power switch is on. The dimming controller receives a switch monitoring signal indicative of the state of the power switch. An average current flowing through the light source has a first value if the power switch is on. The dimming controller is operable for adjusting the average current based on the switch monitoring signal. A current flows from the AC power source through the current path to ground when the power switch is off.

Abstract: A power management system includes a first switch, a second switch, and a controller coupled to the first and second switches. The first switch has a first transfer terminal. The second switch has a second transfer terminal. The controller controls power conversion by turning on a third switch periodically. The first and second transfer terminals and a third transfer terminal of the third switch are coupled to a common node. The resistance between the first transfer terminal and the common node, the resistance between the second transfer terminal and the common node, and the resistance between the third transfer terminal and the common node are substantially equal to zero.

Abstract: A battery management system for a battery pack comprises a battery module and a controller. The controller comprises a voltage detection and control circuit, wherein the controller comprises a voltage to current converter. A cell voltage is converted to current and produces a voltage detected at an input to one or more logic devices. The level of voltage detected is dependent upon the current output of the voltage to current converter and a threshold current. The output of the one or more logic devices is received by a controller, and the controller is operable to control the charging and discharging of the battery cell based on the logic device output.

Abstract: A circuit includes a transformer and a controller. The transformer includes a primary winding and a secondary winding, and operates in multiple switching cycles. A switching cycle includes a charging period and a discharging period. During the charging period, the transformer is powered by the input voltage and a current flowing through the primary winding increases. During the discharging period the transformer discharges to power the load and a current flowing through the secondary winding decreases. The controller includes a pin that receives a first feedback signal indicating the input voltage during the charging period and receives a second feedback signal indicating an electrical condition of the secondary winding during the discharging period. The controller generates a first control signal and a second control signal to regulate the input voltage and an output current flowing through the load, respectively.

Abstract: An operational amplifier with different power supply voltages includes an input stage and an output stage. The input stage includes a current source for providing a bias current, and a differential input circuit for receiving the bias current and differential input voltage signals, and converting the differential input voltage signal to differential input currents. The input stage is supplied by a first power supply voltage. The output stage includes a load circuit coupled to the differential input voltage signal and for receiving the differential input currents, and outputting a single ended output voltage signal. The output stage is supplied by a second power supply voltage. The second power supply voltage is lower than the first power supply voltage.

Abstract: A circuit used for determining a cell number of several battery cells. The circuit includes a detection block and a controller, and operates in a first detection mode and a second detection mode. The detection block is coupled to each of the battery cells. In the first detection mode, the detection block provides a terminal voltage signal indicative of a terminal voltage of a battery cell. In the second detection mode, the detection block provides a cell voltage signal indicative of a cell voltage of the battery cell. The controller compares the terminal voltage signal with a first threshold in the first detection mode and compares the cell voltage signal with a second threshold in the second detection mode, and provides a cell count signal indicative of the cell number based on the terminal voltage signal and the cell voltage signal.

Abstract: A battery circuit includes a monitoring circuit, an integrator circuit, and a comparator. The monitoring circuit can be used to monitor a cell and generate a monitoring signal indicating a cell voltage of the cell. The integrator circuit accumulates a difference between the monitoring signal and a first predetermined threshold over a time period to generate an integrating output. The comparator compares the integrating output to a second predetermined threshold and generates a control signal.

Abstract: A circuit includes a first resistor, a second resistor, a voltage follower and a current mirror. The first resistor converts a current flowing through the first resistor to a voltage drop between positive and negative sides of the first resistor. The second resistor is coupled to the negative side of the first resistor. The voltage follower is coupled to the positive side of the first resistor via a non-inverting terminal, and coupled to the negative side of the first resistor through the second resistor via an inverting terminal to cause a voltage at the inverting terminal to follow a voltage at the non-inverting terminal. The current mirror is coupled to the voltage follower to provide a sensing current proportional to the current flowing through the first resistor.

Abstract: A battery management system with synchronized data sampling for a battery pack including multiple battery cells is disclosed. The battery management system includes a plurality of local monitors coupled to a plurality of battery cells and operable for sampling status information for the battery cells. The battery management system further includes a central controller coupled to the local monitors and operable for broadcasting a sample command to the local monitor synchronously, wherein the local monitors start to sample the status information for the battery cells in response to the sample command.

Abstract: A signal synchronizing system includes comparison circuitry and control circuitry. The comparison circuitry compares a synchronizing signal with an input signal to generate a comparison result. The control circuitry adjusts the synchronizing signal into a range that is determined by the input signal, and controls the range according to the comparison result.

Abstract: A satellite navigation system receiver that includes a counter and a controlling unit is described. The counter may be driven by a reference clock signal having a reference clock frequency. The controlling unit can calculate a correction value indicative of a corrected reference clock frequency by comparing an increment of the counter values during a time period with an increment of the navigation system times during the time period. The controlling unit can generate a calculated navigation system time according to the correction value.

Abstract: A power converter includes a transformer operated in multiple switching cycles. At least one switching cycle includes a charging period, a discharging period, and an adjusting period. The transformer has a primary winding coupled to a power source and a secondary winding coupled to a load. During the charging period the transformer is powered by the power source and a current flowing through the primary winding increases. During the discharging period the transformer discharges to power the load and a current flowing through the secondary winding decreases. A ratio of a duration of the discharging period to a total duration of the charging period, the discharging period and the adjusting period is constant.

Abstract: A circuit for charging a battery may include a switch operable for conducting a current flowing through the switch, and a first amplifier coupled to the switch and operable for adjusting the current according to an amount of power dissipation associated with the switch.

Abstract: A battery management system can include a battery having a plurality of cells, a plurality of devices coupled to the battery, and a control unit coupled to a first device of the devices. The devices can assess the statuses of the cells. The control unit can communicate with a destination device of the devices via a default path and can communicate with the destination device via a backup path if an undesirable condition occurs in the default path.

Abstract: A circuit for driving a light source, e.g., an LED light source, includes a converter, a sensor, and a controller. The converter converts an input voltage to an output voltage across the LED light source based upon a driving signal. A duty cycle of the driving signal determines an average current flowing through the LED light source. The sensor is selectively coupled to and decoupled from the converter based upon the driving signal. The sensor generates a sense voltage indicative of a current flowing through the LED light source when the sensor is coupled to the converter. The controller is coupled to the converter and sensor. The controller compares the sense voltage to a reference voltage indicative of a predetermined average current through the LED light source to generate a compensation signal and generates the driving signal based upon the compensation signal.

Abstract: A differential driving circuit for powering a light source is disclosed. The differential driving circuit includes a first set of switches and a second set of switches. A first current from a power source flows through the first set of switches to charge a first energy storage element when the first set of switches are turned on. A second current from the first energy storage element flows through the second set of switches to power the light source when the second set of switches are turned on. The differential driving circuit further includes a second energy storage element coupled to the light source in parallel and for providing a differential voltage to the light source.