Variable-gain amplifier claims to deliver the highest gain and bandwidth

The device's combination of gain, bandwidth, wide operating temperature range and wide supply voltage range gives designers more flexibility than any VGA in its
class. Competing solutions, in comparison, are typically module based or require two or more cascaded VGAs to provide similar gain range - with both options adding to materials cost and board area.

Designed for high-voltage and wide temperature applications, the AD8336 VGA provides 100 MHz bandwidth over a gain range of 60 dB, more than twice the bandwidth of competing VGAs that operate at much lower supply voltages. The AD8336 includes a voltage feedback op-amp at its input that allows the gain to be externally adjusted. The nominal preamp gain is 4x (12 dB); a gain of 20x (26 dB) can be obtained at a reduced bandwidth. The AD8336 operates at a maximum gain range of 0 dB to 60 dB with the preamp gain set to 26 dB.

Unlike competing dc-coupled VGAs, whose bandwidth degrades as gain increases, the AD8336 provides 100-MHz performance over the 60-dB gain range - from -14 dB to +46 dB. The low input referred noise of 3.2 nV/root-Hz allows the VGA to process very small signals while the large usable supplies expand the dynamic range by a factor of four (12 dB) from +/-3 V to +/-12 V, since the noise level stays the same for all supplies. The AD8336 also operates over the extended industrial temperature range
of -55 degrees C to 125 degrees C with unequalled precision, while a power-adjust pin allows power to be traded for speed in applications that need large supply voltages yet where slower speed is acceptable.

The AD8336 features low power of 150 mW at a +/-3 V supply, low noise of 3.2 nV/ root-Hz, low output offset of less than 50 mV at maximum gain and a slew rate of 450 V/microsecond for a 2-V step. The inclusion of a voltage feedback op-amp at its input allows the AD8336 to accommodate both inverting and non-inverting topologies, and thereby, a dual polarity VGA. The preamp
gain can be set from 12 dB to 26 dB.

The AD8336 is suitable for use with analog-to-digital converters (ADCs) such as the AD7656, AD7634, AD7951, and AD9460. The new VGA can be controlled by many types of digital-to-analog converters (DACs), including unipolar and bipolar DACS, since the gain control input is differential to the AD8336 and the gain control common-mode voltage increases with increasing supply. Compatible DACs include the 8-bit AD5300 and AD5330 and the 10-bit AD5331 and AD5338 in space-constrained applications.