SYSTEM AND METHOD FOR DETERMINING ADAPTER CURRENT LIMIT

摘要

An electronic device that determines an adapter current limit for a power adapter, including a regulator, a voltage comparator, and a controller. The regulator regulates an adapter output current level to prevent it from exceeding the adapter current limit, and provides a regulation signal during regulation. The voltage comparator provides an under-voltage signal when adapter output voltage level falls below a low voltage threshold. The controller initially sets the adapter current limit at a lowest level, increases the adapter current limit by an incremental amount when the regulation signal is provided, and when the under-voltage signal is provided, decreases the adapter current limit by the incremental amount to determine a final adapter current limit. The final adapter current limit is at or near the actual maximum current limit of the power adapter. The adapter current limit may be increased only when regulation occurs for at least a predetermined time period.

主权项

1. An electronic device that determines an adapter current limit for a power adapter when the power adapter is connected to the electronic device, said electronic device comprising:
a regulator that regulates an adapter output current level at an adapter current limit to prevent said adapter output current level from exceeding said adapter current limit, and that provides a regulation signal indicative thereof; a voltage comparator that provides an under-voltage signal when a low voltage threshold exceeds an adapter output voltage level; and a controller that provides and adjusts said adapter current limit, wherein said controller is operative to:
initially set said adapter current limit at a predetermined lowest level;increase said adapter current limit by an incremental amount when said regulation signal is provided; andwhen said under-voltage signal is provided, decrease said adapter current limit by said incremental amount to determine a final adapter current limit.