Richtek Technology Corporation

Li-Wei Lee

Nien-Hui Kung

Kwan-Jen Chu

Ying-Hsin Hsing

Chien-Ping Lu

Chun-Tsung Chen

Ta-Yung Yang

Jing-Meng Liu

Wei-Che Chiu

Hsuan-Kai Wang

Ko-Ching Su

Chia-Hsiang Lin

Wei-Teng Chang

Chen-Hsiang Hsiao

The present invention discloses a high efficiency charging system and a charging circuit therein. The high efficiency charging system includes a power supplier and a power receiver, which are connected via a transmission wire so that power is transmitted from the power supplier to the power receiver. The power receiver includes a voltage conversion circuit and a control circuit. The voltage conversion circuit converts an adjustable input voltage provided by the power supplier to an output voltage and generates an output current for charging a battery. The voltage conversion circuit adaptively adjusts the output current according to a voltage drop between the adjustable input voltage and the output voltage. The control circuit senses the adjustable input voltage and the output voltage and instructs the power supplier to adjust the output voltage according to the voltage drop between the adjustable input voltage and output voltage.

High efficiency charging system and charging circuit therein

The present invention discloses a charge control circuit for supplying power from an external power source to a first common node and charging a second common node from the first common node. A regulator circuit is coupled between the external power source and the first common node, and a transistor is coupled between the first common node and the second common node. The present invention detects an operation parameter of the transistor and controls an internal voltage source to generate a non-predetermined voltage difference accordingly. When the sum of the voltage at the second common node and the non-predetermined voltage is equal to or higher than the reference voltage, the voltage at the first common node is regulated to a level higher than the voltage at the second common node, and the transistor is in an optimum conductive state.

Charging control circuit

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.

Charger with detection of power input type

Charger and portable device having the same

A charging circuit with an application system thereof provides an error amplifier to control a transistor switch for controlling the charging power source to charges the battery. When the voltage difference between the power source and load terminals of the transistor switch drops along with the transistor switch being turned on, the output voltage of the error amplifier changes as well to increase the turning-on resistance of the transistor switch such that the voltage difference between the power source and load terminals is capable of maintaining at a value above a certain reference level for avoiding the unstable state resulting from the charging circuit being turned on and off frequently.

Charging circuit with application system thereof

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.

Power safety system

The present invention discloses an overvoltage protection (OVP) circuit for use in a charger circuit system, comprising: a power transistor electrically connected between a voltage supply and a battery; an OVP circuit which turns off the transistor when a voltage supply exceeds a threshold value; and a multiplexing circuit electrically connected between an output of the OVP circuit and the gate of the transistor. The present invention also discloses a charger circuit with an OVP function, comprising: a single power transistor electrically connected between a voltage supply and a battery; an OVP control circuit which turns off the power transistor when a voltage supply exceeds a threshold value; and a charger control circuit which controls the gate of the power transistor to determine a charge current to the battery when the voltage supply does not reach the threshold value.

Overvoltage protection circuit for use in charger circuit system and charge circuit with overvoltage protection function

An automatic switch method and apparatus are used to set the output current of a USB by slowly increasing the output current under monitoring the voltage on the USB. If the USB could normally operate until the output current reaches a threshold value, a higher level is set for the output current, otherwise a lower level is set instead. The process may be performed periodically to dynamically determine the output current for the USB.

Growing community of inventors

Zhubei, Taiwan

Li-Wei Lee