Three Apple patents have appeared at the US Patent & Trademark Office. They involve portable devices, location information and power management. Following is a summary of each.

Patent number 20100205472 involves a method and system for operating a portable electronic device in a power-limited manner. Improved techniques to manage operation of a portable electronic device having a substantially depleted battery when power is available from an external, power-limited source are disclosed. In one embodiment of the invention, the substantially depleted battery can be initially charged while a power-intensive operation is delayed. Once the battery has adequate charge to assist the external, power-limited source in powering the portable electronic device, the power-intensive operation can be performed. In this manner, power consumption of a portable electronic device can be managed so that reliable operation is achieved without exceeding limits on power being drawn from an external, power-limited source. The inventors are David John Tupman and Steven Bollinger.

Patent number 2010021567 is for communicating location information between a portable device and an accessory. Location data is exchanged between a portable media device and an accessory. If the portable media player is equipped with location determining capability, the portable media device can communicate its location data to the accessory, and the accessory can use this location data to perform various tasks. If the accessory is equipped with location assistance capability, the accessory can communicate location data to the portable media device, and the portable media device can use this location data to perform various tasks. The inventors are Gregory T. Lydon, Ronald Keryuan Huang, Lawrence G. Bolton, Emily Clark Schubert and Jesse lee Dorogusker.

Patent number 20100204946 is for a self-test power management unit. Systems and methods are disclosed for a self-testing power management unit (PMU) in an electronic device. Self-testing may enable the testing of PMU power supply outputs while reducing the need for test points to conserve circuit board real estate. In one embodiment, a PMU is placed in self-test mode, and a test controller may perform capacitance tests on each power supply output. Once the capacitance test has been performed on each power supply output, the PMU may be placed in normal operating mode, and voltage tests may be performed on each power rail. Once voltage tests have been performed on all power rails in the PMU, the self-test may be complete. In some embodiments, the test controller may communicate with a test multiplexer to select the power supply output for testing. Further, the measurements resulting from the capacitance and voltage tests may be converted to a digital signal through an analog-to-digital converter on the PMU. The inventors are Daniel Adam Warren and John Joseph Sullivan.