The LMH6521 contains two high performance, digitally controlled variable gain amplifiers
(DVGA).
Both channels of the LMH6521 have an independent, digitally controlled attenuator
followed by a high linearity, differential output amplifier. Each block has been optimized for low
distortion and maximum system design flexibility. Each channel has a high speed power down mode.
The internal digitally controlled attenuator provides precise 0.5-dB gain steps over a
31.5-dB range. Serial and parallel programming options are provided. Serial mode programming uses
the SPI interface. A pulse mode is also offered where simple up or down commands can change the
gain one step at a time.
The output amplifier has a differential output allowing 10-VPPD
signal swings on a single 5-V supply. The low impedance output provides maximum flexibility when
driving filters or analog to digital converters.
