AD8260 includes a high current driver, usable as a transmitter, and a low noise, digitally programmable variable gain amplifier (DGA), useable as a receiver.

The receiver section consists of a single-ended input preamplifier, and linear-in-dB, differential-output VGA. Usable at dc and frequencies to 80MHz; the -3dB bandwidth is 180MHz. The driver-amplifier delivers ±300mA, well suited for driving low impedance loads, even when connected to a 3.3V supply.

The AD8260 DGA is ideal for trim applications and has a gain span of 30dB, in 3dB steps. Excellent bandwidth uniformity is maintained across the entire frequency range. The DGA’s low output-referred noise is advantageous in driving high speed ADCs. The differential output facilitates the interface to modern low voltage high speed ADCs.

Single-supply and dual-supply operation makes the part versatile and enables gain control of negative-going pulses, such as generated by photodiodes or photo-multiplier tubes, as well as processing band-pass signals on a single supply. For maximum dynamic range, it is essential that the part be ac-coupled when operating on a single supply.

The AD8260 preamplifier (PrA) is user configurable with external resistors for gains greater than 6dB, as with any high frequency op amp, the gain is inverting or non-inverting. The DGA is characterized with a non-inverting PrA gain. The attenuator has a range of 30dB and the output amplifier has a gain of 18.06dB. The lowest non-inverting gain range is -6dB to +24 dB and shifts up with increased PrA gain. The gain is controlled via a parallel port (Pin GNS0 to Pin GNS3) with 10 gain steps of 3dB per code. For any non0used code, the preamplifier and DGA are disabled.

The AD8260 can operate with single or dual supplies from 3.3V to 5V. An internal buffer normally provides a split supply reference for single-supply operation; an external reference can also be used when the VMID buffer is shut down.