The ADA4939-1 / ADA4939-2 are low noise, ultralow distortion,
high speed differential amplifiers. They are an ideal choice for
driving high performance ADCs with resolutions up to 16 bits
from dc to 100 MHz. The output common-mode voltage is user
adjustable by means of an internal common-mode feedback loop,
allowing the ADA4939-1 / ADA4939-2 output to match the input
of the ADC. The internal feedback loop also provides exceptional
output balance as well as suppression of even-order harmonic
distortion products.
With the ADA4939-1 / ADA4939-2, differential gain configurations
are easily realized with a simple external feedback network of four
resistors that determine the closed-loop gain of the amplifier.
The ADA4939-1 / ADA4939-2 are fabricated using Analog Devices,
Inc., proprietary silicon-germanium (SiGe), complementary bipolar
process, enabling them to achieve very low levels of distortion with
an input voltage noise of only 2.3 nV/√Hz. The low dc offset and
excellent dynamic performance of the ADA4939-1 / ADA4939-2
make them well suited for a wide variety of data acquisition and
signal processing applications.
The ADA4939-1 (single) is available in a 3 mm × 3 mm, 16-lead
LFCSP, and the ADA4939-2 (dual) is available in a 4 mm × 4 mm,
24-lead LFCSP. The pinouts are optimized to facilitate printed
circuit board (PCB) layout and minimize distortion. The
ADA4939-1/ADA4939-2 are specified to operate over the
−40°C to +105°C temperature range; both operate on supplies
between 3.3 V and 5 V.
Applications
- ADC drivers
- Single-ended-to-differential converters
- IF and baseband gain blocks
- Differential buffers
- Line drivers
