RF-Detecting Controllers Simplify Control-Loop Design

The MAX9930-MAX9933 low-cost, low-power logarithmic amplifiers from Maxim Integrated Systems control RF power amplifiers and transimpedance amplifiers. They also detect RF power levels. The devices operate in the 2-MHz to 1.6-GHz range and have typical dynamic range of 45 dB with an accuracy of ±1 dB. Available with three different input-voltage ranges, the series eliminates the need for external attenuators, simplifying amplifier control-loop design. The MAX9930 and MAX9933 measure voltages from –58 dBV to –13 dBV, the MAX9931 from –48 dBV to –3 dBV, and the MAX9932 from –43 dBV to +2 dBV.

The MAX9930-MAX9933 consume 5.9 mA with a 5-V supply, and the typical shutdown current is 13 µA. To ensure a glitch-free output, the devices assert a power-on delay when coming out of shutdown. The MAX9930-MAX9933 are available in an eight-pin microMAX package that achieves excellent temperature stability over the extended operating range of –40°C to 85°C. The amplifiers are well-suited for a variety of wireless and gigabit passive optical network (GPON) fiber video applications, such as transmitter power measurement and received signal-strength indication (RSSI) for terminal devices.