Miniature overvoltage clamp offers protection for portable equipment

Supporting a battery charger output range of 3 to 30V, the device passes the voltage through to the ic only up to a safe clamp voltage limit, which is factory set at 11V. The AP9060's feedback loop maintains the clamped output voltage level by backing off the drive to its P channel mosfet switch. With an ultra low bias current, the device is also designed to minimise self heating, thereby increasing reliability. In addition, the AP9060's use of a low resistance P channel mosfet as the pass element ensures that any EMI issues are removed. This is achieved by avoiding noise generation on the input supply circuit normally associated with the charge pump of alternative N channel mosfet solutions. The AP9060 also supports reverse current operation, allowing it to pass up to a maximum of 1A from the ic to a load connected to a usb port.