Two of the DACs are configured to regulate MAX17503 DC-DC converter for optimal power output for the PA. In Figure 2, three of the ADCs are configured for 0 to 2.5V input range for current-sense measurement and the other three are configured for 0 to 10V input range for supply voltage detection. Internal schematic of MAX11300 for PA biasing. It consists of six single-ended ADCs, four DACs, two switches, and two GPOs.įigure 2. The MAX11300 internal design as used in this PA bias reference design is shown in Figure 2. The design uses the highly configurable input/output capability of the MAX11300 to bias an Infineon PTAM210152M 15W, two-stage, LDMOS power amp. Figure 1 also shows power control and monitoring for RF PA. The microcontroller section is powered through USB power, whereas the rest of the circuit is powered by a separate 36V DC supply. The USB interface to the microcontroller and serial interface to the MAX11300 are digitally isolated from the main circuit through the MAX14850. Efficient, adjustable drain voltage supplyįigure 1.Gate biasing of first-stage and second-stage amplifiers.Two external and one internal temperature monitors.

Drain voltage and current of first- and second-stage amplifiers.Current measurement through Maxim current-sense amplifier ( MAX44285).

Accurate voltage and current measurement.

Monitor, biasing, and control for frequency division duplex (FDD) and time division duplex (TDD) radio frequency (RF) power amplifiers.

All the features of this reference design are listed below. The design utilizes all of the MAX11300’s analog peripherals, while only requiring one MAX11300 device to both bias and monitor a 2-stage RF power amp. The MAX11300 provides a highly integrated solution for the RF power amplifier biasing infrastructure. In this case, an Infineon PTMA210152M-20W is used but any Power Amplifier can be used. The MAXREFDES39# power amplifier (PA) bias reference design uses the MAX11300, also called a programmable mixed-signal I/O (PIXI ™ IC), to bias and monitor a power amplifier for an RF base station application.

Power amplifier pa