Abstract: An apparatus for transferring serial data (e.g., a serial interface using a single wire) generally includes a detector configured to detect a first level time period and a second level time period of an input signal, and a computing unit configured to compute a duty or duty cycle of the input signal and generate an output signal based on the duty or duty cycle.

Abstract: An apparatus for transferring serial data (e.g., a serial interface using a single wire) generally includes a detector configured to detect a first level time period and a second level time period of an input signal, and a computing unit configured to compute a duty or duty cycle of the input signal and generate an output signal based on the duty or duty cycle.

Abstract: A battery charge controller has charge termination values that can be adjusted according to the initial charging current values so that charging is discontinued at a same charge level for all battery cells to prevent overcharging and undercharging. The battery charge controller includes a DC/DC converter that is coupled to a supply voltage and that provides a charging current to a battery, and a gain controller coupled to the DC/DC converter. The gain controller provides first and second gain-adjusted signals associated with the charging current. The charge controller further includes a charge termination detector that compares the level of the second gain-adjusted signal to a first predetermined reference signal and based on the comparison generates a charge termination signal. A pulse-width controller is coupled to the DC/DC converter.

Abstract: Disclosed is an SMPS with a constant power control circuit.

Abstract: A control circuit controls a battery charger so as to prevent damage to NiCAD or NiMH batteries resulting from overheating due to overcharging. During charging, the battery voltage is monitored through a filter, buffer, amplifier and sample and hold circuit. The sampled voltage is time differentiated to determine its rate of change, and a control signal is generated for switching the battery charger from a rapid charge mode to a trickle charge mode when the negative rate of change of the battery voltage exceeds a pretermined reference voltage, thereby identifying that the battery voltage has started to decay from its peak voltage.

Abstract: A frequency modulator controls the center frequency and modulation factor at the same time with one control signal. The frequency modulator includes a voltage-to-current converter that receives an input voltage signal to be modulated, a reference voltage signal, and a control voltage signal, and generates an output current signal by combining the input voltage signal and the control voltage signal. The input voltage signal is amplified by a transconductance amplifier. The control voltage signal is converted into a gain signal which is used to vary the transconductance of the amplifier. A voltage controlled oscillator generates a frequency modulated signal responsive to the output current signal. The center frequency and modulation factor can be controlled by adjusting the value of a resistor in the current-to-voltage converter, a capacitor in the voltage control oscillator, or the control voltage signal.