CURRENT LIMIT CIRCUIT FOR POWER AMPLIFIERS

摘要

According to one embodiment of the invention, a circuit arrangement includes a regulator circuit (104). The circuit arrangement further includes a current limit circuit (102) coupled to the regulator circuit. The circuit arrangement further includes a power amplifier (1) coupled to the regulator circuit, where the power amplifier is configured to draw a first current (135) from the regular circuit. The current limit circuit is configured to decrease the ni&t current when the first current causes a second current (127) in the current limit circuit to be greater than a reference current (141). According to this embodiment, the second current is a mirror current of the first current. The current limit circuit includes a current sink (122), where the current sink is configured to sink the reference current to ground (129). The current limit circuit further includes a feedback loop (formed by transistors (128, 130), and (132), where the feedback loop causes the second current to be substantially equal to the reference current.