Datasheet

The DA1855A is a stand-alone,
high-performance 100 MHz differential
amplier. It is intended to act as a
signal conditioning preamplier for
oscilloscopes, digitizers and spectrum
analyzers, providing differential
measurement capability to instru-
ments having only a single-ended
input. When used with a DA1855A,
oscilloscopes can obtain Common
Mode Rejection Ratio (CMRR) and
overdrive recovery performance levels
previously unobtainable.
Amplier gain can be set to 1 or 10.
A built-in input attenuator can
be separately set to attenuate
signals by a factor of 10, providing
gains of 10, 1, or 0.1 and common
mode dynamic range of ±15.5 V (÷1)
or ±155 V (÷10). Optional probes
increase the maximum input signal
and common mode ranges in
propor tion to their attenuation ratio but
do not exceed their maximum input
voltage rating. Effective gain of the
DA1855A, including probe attenuation,
amplier gain and attenuator settings,
is automatically displayed.
The DA1855A has a bandwidth of
100 MHz, but any one of the three
3-pole bandwidth limit lters can be
selected to reduce bandwidth to
20 MHz, 1 MHz or 100 kHz to limit
noise above the frequency of interest.
The DA1855A output is carefully
limited to ±500 mV, so that the
oscilloscope is not overdriven by large
inputs. This allows many oscilloscopes
to directly measure the settling of
D/A converters with 14-bit (60 ppm)
precision, better than any other
differential comparator.
The DA1855A features a built-in
Precision Voltage Generator (PVG)
that can be set to any voltage between
±15.5 V (±10 V in Differential Offset)
with up to 100 µV resolution. The PVGs
output can be selected as an input to
the inverting (-) input of the amplier
DA1855A
High-performance
100 MHz Differential
Amplier
Key Features
•
Full control from oscilloscope
through ProBus interface
•
DC to 100 MHz bandwidth
•
Outstanding 100,000: 1 Common
Mode Rejection Ratio (CMRR)
•
Gain of X1 or X10
•
Industry-leading overdrive recovery
•
Low noise
•
Selectable BW limiting
•
Two gain control modes when
connected to a Teledyne LeCroy
oscilloscope
•
Built-in Precision Voltage
Generator (PVG)
•
Comparator and true
differential offset modes
The DA1855A is a stand-alone, high-performance differential amplier providing the
fastest overdrive recovery of any commercially available product. This unique capability
allows the amplier to make measurements that would normally be limited by oscilloscope
overdrive recovery.