Many of today's high-frequency designs, such as HDTV tuners, cable modems, and voice-over-Internet-protocol receivers, require automatic gain control (AGC). Creating an AGC amplifier with sufficient gain, gain range, and noise performance is a major part of any design effort.
California Eastern Labs simplifies that process with NEC's UPC3221GV (see the figure). The device provides 60 dB of gain, a 50-dB dynamic gain range, a noise figure of 4.2 dB, and a third-order intercept (IP3) of +2.5 dB at minimum gain. Frequency ranges from 10 to 100 MHz, suiting it for IF applications.
The 3321 is made with NEC's 10-GHz fT NESAT II AL silicon bipolar process. It consists of a two-stage gain-control amplifier followed by a fixed-gain video amplifier. Differential inputs and outputs provide good noise performance, often eliminating the need for shielding. The differential I/O makes it easy to connect to surface-acoustic-wave (SAW) filters at the input and analog-to-digital converters at the output.
Housed in an eight-pin SSOP package, the 3321 operates from a 5-V supply. It costs less than $1 in 10,000-unit quantities. Evaluation boards are also available.
California Eastern Laboratories