LeCroy DA1855A-PR2 - 2 Ch, 100 Mhz, Differential Amplifier With Precision Voltage Source

Two independent model DA1855A amplifiers packaged in one housing with one line power input connection. The housing is intended for desktop use, where it can be placed under an oscilloscope.

2 Channel with fast overdrive recovery, calibrated offset, and selectable LP filters
Differential amplifiers are intended to act as signal conditioning preamplifiers for oscilloscopes and network and spectrum analyzers, providing differential measurement capability to instruments having only a single-ended input. The "-PR2" version of each amplifier is a dual-channel unit. The DXC series differential input cables are matched to the characteristics of the amplifier.

2 Channel 100 MHz Differential Amplifier

The DA1855A series is comprised of 2 models which differ in physical configuration. Both contain the same 100 MHz differential amplifier which provides high common mode rejection, extremely fast overdrive recovery, selectable ÷1 or ÷10 attenuation, selectable X1 or X10 gain, a 5 - 1/2 digit Precision Voltage Generator (PVG), selectable upper bandwidth limiting filters, and effective gain display. and ± 500 mV output swing limiting. The PVG is provides a calibrated reference for Differential Offset or Comparison modes. The PVG reference voltage is also available through a BNC connector on the rear panel.

Overdrive Recovery
With a ÷100 probe, the DA1855A settles to within 100 mV referred to input, from a 400 V input signal within 100 ns. With attenuating probes, this allows the in circuit measurement of dynamic saturation in switch mode power converter switching devices

Comparator Mode
The DA1855A becomes a differential comparator when the internal PVG output is selected as the amplifier’s inverting (-) input. In this mode, the DA1855A can be used to very accurately measure relatively small signals that are riding on large AC or DC components. Due to the precision of the voltage generator, an oscilloscope, when used with the DA1855A, can make voltage measurements that are much more accurate than the oscilloscope is capable of by itself. The output of the PVG is available for external use via a rear panel connector.

True Differential Offset Mode
The DA1855A has built-in Precision Voltage Generator can be used to generate a true differential offset while still allowing both inputs to be used as differential inputs. The offset range can be as high as ±50,000 divisions and the generator has 5 1/2 digit resolution. This mode facilitates making measurements such as changes to a transistor’s base to emitter voltage caused by variations in temperature and/or current. Used in this mode, the voltage generator can be set to a value that will zero out the static value of the junction’s on voltage. The DA1855A’s differential measurement capability will reject any dynamic signal common to both sides of the junction, and the oscilloscope is left to measure only the changes in the junction voltage.

Autobalance
Each time either gain setting button is pressed, the DA1855A automatically adjusts the amplifier’s DC balance.