Patent ID: 8270917
Filing Date: 2012-09-18
Classification: H03G

Abstract:
1. a gain system for a wireless transmitter core comprising: an automatic gain control circuit for providing differential gain control voltages (V GAIN+, V GAIN−) corresponding to a level of gain in response to a control signal (VCONT), the automatic gain control circuit controlling the differential gain control voltages to have a linear relationship with the control signal; a variable gain amplifier for amplifying a data signal IN with the level of gain in response to the differential gain control voltages, an output power of the variable gain amplifier varying between a minimum output power at a minimum gain level of the differential gain control voltages and a maximum output power at a maximum gain level of the differential gain control voltages, the variable gain amplifier receiving a variable current (I VAR) for operating the variable gain amplifier; and, a current control circuit for adjusting the variable current in response to the differential gain control voltages, the current control circuit minimizing the variable current at the minimum output power and maximizing the variable current at the maximum output power; wherein the current control circuit includes a combination of a proportional to absolute temperature current source and a complementary to absolute temperature current source to generate the variable current.