摘要:
A charger for a portable device includes a USB detector connected to a data pin to detect the effective resistance on the data pin before a USB transceiver is enabled, to identify USB or adapter plug in and control a charging current for a battery accordingly.
摘要:
A charger for a portable device includes a USB detector connected to a data pin to detect the effective resistance on the data pin before a USB transceiver is enabled, to identify USB or adapter plug in and control a charging current for a battery accordingly.
摘要:
A power safety system includes a first MOS, a second MOS, a switch and a body controller. The first MOS is connected between a power input and a power output. The second MOSFET is connected between the power output and a charging output. The switch has an end connected to the body of the first MOS, and the opposite end switched between the source and the drain of the first MOS. A body controller controls the switch according to the voltage at the power input and the voltage at the power output, to connect the body of the first MOS to the source or the drain of the first MOS. By switching the switch, the first MOS will have a parasitic diode effective to prevent a reverse current from the power output to the power input.
摘要:
The present invention discloses a single wire transmission interface comprising: a signal detection circuit detecting level switchings of a transmission signal from a single wire, and generating an enable signal and a decoded signal corresponding to the transmission signal, the level switchings including first switchings from a first level to a second level and second switchings from the second level to the first level, wherein the enable signal starts according to one first switching of the transmission signal, and stops when no first switching occur in a predetermined period after one second switching of the transmission signal, and wherein rising edges (or falling edges) of the decoded signal correspond to the first switchings of the transmission signal; a counter, under enablement by the enable signal, counting a number of the rising edges (or the rising edges) of the decoded signal or the first switchings of the transmission signal, and generating a count; a single short pulse generator generating a short pulse according to the start of the enable signal to reset the decoded signal.
摘要:
For output current detection of a voltage regulator, the currents in a high-side transistor and a low-side transistor of the voltage regulator are sensed and summarized to a summed current to flow through a setting resistor. The voltage variation on the setting resistor is monitored to provide a feedback signal for feedback control in the voltage regulator. This detection scheme removes the current sensing resistor from the charging current path of the voltage regulator to prevent efficiency loss on it, and is much less sensitive to noise interference because greater voltage variation is available by using a greater setting resistor.
摘要:
A fast start-up low-voltage bandgap reference voltage generator uses two current generators to provide a first current having a positive temperature coefficient and a second current having a negative temperature coefficient, respectively, and a resistor to generate a temperature independent output voltage according to the sum of the first and second currents. The current generator for providing the first current has a self-bias circuit which uses a single MOSFET to establish the first current, and thereby avoids error caused by mismatched MOSFETs.
摘要:
A hybrid battery charger includes a control circuit and a power stage. The control circuit includes an error amplifier to generate a first error signal and a second error signal according to an output voltage and an output current of the hybrid battery charger, a linear controller to generate a first control signal according to the first error signal, a PWM controller to generate a second control signal and a third control signal according to the second error signal, and according to a mode signal, a multiplexer to select the first control signal for the power stage to operate the hybrid battery charger in a linear mode, or the second and third control signals for the power stage to operate the hybrid battery charger in a switching mode.
摘要:
Methods are proposed for a buck boost voltage regulator to monitor the output voltage or both the inductor current and the output voltage of the buck boost voltage regulator to control the buck boost voltage regulator to reduce the switching times of the power switches of the buck boost voltage regulator to improve the light load efficiency of the buck boost voltage regulator.