Digitally Programmable IF VGA Improves Signal Integrity Performance
Wed, 01/14/2009 - 9:25am
The LT5554 is a broadband digitally programmable gain IF amplifier, featuring a 48 dBm OIP3 (output 3rd order intercept) at 200 MHz. Additionally, the amplifier has very low noise, enabling very high dynamic range performance in wireless communication receivers and signal processing systems. Its gain is digitally controlled from 2 to 18 dB by a 7-bit parallel word, producing the finest 0.125 dB steps gain control granularity of any amplifier available. The amplifier settles in less than 5 ns from a gain change, producing low glitch noise and supporting very fast and accurate AGC (automatic gain control) performance. Its output stage has robust capability to drive into 50? loads with low distortion and noise. Thus, it enables high spurious-free dynamic range performance in ADC systems.