ADL5721

Data Sheet

Rev. 0 | Page 10 of 15

THEORY OF OPERATION

The ADL5721 is a narrow-band, high performance, low noise

amplifier targeting microwave radio link receiver designs. The

monolithic SiGe design is optimized for microwave radio link

bands ranging from 5.9 GHz to 8.5 GHz.

The unique design of the ADL5721 offers a single-ended 50 Ω

input impedance and provides a 100 Ω balanced differential

output. This LNA is ideal for driving Analog Devices differential

downconverters and RF sampling ADCs.

The ADL5721 provides cost-effective noise figure performance

without requiring more expensive III-V compounds process

technology.

This LNA uses a band switch feature to allow the input P1dB

and noise figure to trade off for optimum system performance.

The BAND pin allows the user to select between two frequency

ranges. A logic low of 0 V on the BAND pin selects the lower

frequency range from 5.9 GHz to 7.2 GHz, whereas a logic high

of 1.8 V selects the higher frequency range from 7.1 GHz to

8.5 GHz.

The ADL5721 is available in an 8-lead, 2.00 mm × 2.00 mm

LFCSP package, and operates over the temperature range of

−40°C to +85°C.