Abstract: An overvoltage protection circuit is configured to protect a battery pack from overvoltage when the battery pack is in charge. The overvoltage protection circuit includes a power supply, an overvoltage protection chip, a controller and switching circuit. The power supply is configured to charge the battery pack. The overvoltage protection chip is electronically connected between the power supply and the battery pack, the overvoltage protection chip comprising a voltage detection pin. The controller is electronically connected to the battery pack and configured to detect whether the battery pack is a high voltage type battery pack or a normal voltage type battery, and outputting corresponding control signals according to the detection. The switching circuit comprises a switch and two voltage dividing circuits, the switch connecting a corresponding voltage dividing circuit to the positive pole of the battery pack and the voltage detection pin under control of the control signal.

Abstract: In a method for correcting errors occurring in attention (AT) commands of a mobile device, the mobile device includes a first user identity module (UIM) chipset, a second UIM chipset, a buffer and a timer. The method sets a response time for a communication between the first UIM chipset and the second chipset according to an AT command, backups the AT command into the buffer, and counts a communication time using the timer. When the communication time exceeds the response time, the method restarts the first UIM chipset using a watchdog timer and restarts the second UIM chipset by resetting voltage levels of I/O pins of the second UIM chipset. The method further clears the communication data stored in the buffer, reads the AT command from the buffer and resends the AT command to control the first UIM chipset to communicate with the UIM second chipset normally.

Abstract: An overvoltage protection circuit is configured to protect a battery pack from overvoltage when the battery pack is in charge. The overvoltage protection circuit includes a power supply, an overvoltage protection chip, a controller and switching circuit. The power supply is configured to charge the battery pack. The overvoltage protection chip is electronically connected between the power supply and the battery pack, the overvoltage protection chip comprising a voltage detection pin. The controller is electronically connected to the battery pack and configured to detect whether the battery pack is a high voltage type battery pack or a normal voltage type battery, and outputting corresponding control signals according to the detection. The switching circuit comprises a switch and two voltage dividing circuits, the switch connecting a corresponding voltage dividing circuit to the positive pole of the battery pack and the voltage detection pin under control of the control signal.

Abstract: In a method for correcting errors occurring in attention (AT) commands of a mobile device, the mobile device includes a first user identity module (UIM) chipset, a second UIM chipset, a buffer and a timer. The method sets a response time for a communication between the first UIM chipset and the second chipset according to an AT command, backups the AT command into the buffer, and counts a communication time using the timer. When the communication time exceeds the response time, the method restarts the first UIM chipset using a watchdog timer and restarts the second UIM chipset by resetting voltage levels of I/O pins of the second UIM chipset. The method further clears the communication data stored in the buffer, reads the AT command from the buffer and resends the AT command to control the first UIM chipset to communicate with the UIM second chipset normally.

Abstract: A central processing unit (CPU) start-up circuit for controlling a CPU of a portable electronic device includes a power management unit (PMU) connected to the CPU, an awaking circuit connected to the CPU, and a main power supply connected to the CPU, the PMU and the awaking circuit. The main power supply provides working electric power to the CPU, the PMU detects the status of the main power supply and generates a status signal (SS) according to the detecting result, the awaking circuit detects the status of the main power supply and generates a waking signal (WS) according to the detecting result, and the SS and the WS are both transmitted to the CPU to cooperatively control the CPU to be switched on and switched off.

Abstract: A central processing unit (CPU) start-up circuit for controlling a CPU of a portable electronic device includes a power management unit (PMU) connected to the CPU, an awaking circuit connected to the CPU, and a main power supply connected to the CPU, the PMU and the awaking circuit. The main power supply provides working electric power to the CPU, the PMU detects the status of the main power supply and generates a status signal (SS) according to the detecting result, the awaking circuit detects the status of the main power supply and generates a waking signal (WS) according to the detecting result, and the SS and the WS are both transmitted to the CPU to cooperatively control the CPU to be switched on and switched off.