| 摘要 |
Method and apparatus are provided for protecting radio frequency (RF) power amplifiers. A circuit ( 10 ) is provided for limiting a supply current to a first stage (Q 3 ) of the RF power amplifier having a second stage (Q 2 ) coupled to the first stage. The circuit comprises a comparator ( 14 ) having first and second inputs and an output, and a switching circuit ( 12, 20, 22, 24 ) having an input coupled to the output of the comparator ( 14 ) and having an output configured to couple to the first stage (Q 3 ). The first input of the comparator ( 14 ) is configured to receive the supply current, and the second input is configured to receive a current supplied to the second stage (Q 2 ). The comparator ( 14 ) is configured to compare a ratio of the supply current to the first stage to the current supplied to the second stage (Q 2 ) with a predetermined value. The switching circuit ( 12, 20, 22, 24 ) is configured to limit the supply current to the first stage (Q 3 ) when the ratio exceeds the predetermined value.
|
