Dual RF LDMOS Bias Controller With Nonvolatile Memory

The MAX11008 controller biases RF LDMOS power devices found in cellular base stations and other wire- less infrastructure equipment. Each controller includes a high-side current-sense Amplifier with programmable gains of 2, 10, and 25 to monitor the LDMOS drain cur- rent over a range of 20mA to 5A. The MAX11008 sup- ports up to two external diode-connected Transistors to monitor the LDMOS temperatures while an internal tem- perature Sensor measures the local die temperature. A 12-bit successive-approximation Register (SAR) analog- to-digital converter (ADC) converts the Analog signals from the programmable-gain Amplifiers (PGAs), exter- nal Temperature Sensors internal temperature measure- ment, and two additional auxiliary inputs. The MAX11008 automatically adjusts the LDMOS bias volt- ages by applying temperature, AIN, and/or drain cur- rent samples to data stored in lookup tables (LUTs). By Maxim Integrated Products