DA1855A High-performance 100 MHz Differential Amplifier Key Features Full control from oscilloscope through ProBus interface The DA1855A is a stand-alone, high-performance differential amplifier providing the fastest overdrive recovery of any commercially available product. This unique capability allows the amplifier to make measurements that would normally be limited by oscilloscope overdrive recovery. The DA1855A is a stand-alone, DA1855A, including probe attenuation, high-performance 100 MHz differential amplifier gain and attenuator settings, Outstanding 100,000: 1 Common amplifier. It is intended to act as a is automatically displayed. Mode Rejection Ratio (CMRR) signal conditioning preamplifier for DC to 100 MHz bandwidth 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) 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. Amplifier gain can be set to 1 or 10. A built-in input attenuator can be separately set to attenuate Comparator and true signals by a factor of 10, providing differential offset modes 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 proportion to their attenuation ratio but do not exceed their maximum input voltage rating. Effective gain of the The DA1855A has a bandwidth of 100 MHz, but any one of the three 3-pole bandwidth limit filters 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. The PVGs output can be selected as an input to the inverting (-) input of the amplifier for operation as a differential SPECIFICATIONS AND ORDERING INFORMATION comparator or applied internally as a true differential offset that are much often more accurate than the oscilloscope is voltage. The PVG is also available for external use through capable of by itself. The output of the PVG is available for a rear panel connector. external use via a rear panel connector. The DA1855A operates from 90 to 250 VAC line without True Differential Offset Mode line switching. High-performance differential probes The DA1855A has built-in Precision Voltage Generator such as the DXC100 /10//100 high CMRR probes are can be used to generate a true differential offset while still recommended. allowing both inputs to be used as differential inputs. The offset range can be as high as 50,000 divisions and the Overdrive Recovery generator has 5 1/2 digit resolution. This mode facilitates With a /100 probe, the DA1855A settles to within making measurements such as changes to a transistor's 100 mV referred to input, from a 400 V input signal base to emitter voltage caused by variations in temperature within 100 ns. With attenuating probes, this allows the in circuit measurement of dynamic saturation in switch and/or current. Used in this mode, the voltage generator mode power converter switching devices. can be set to a value that will zero out the static value Comparator Mode measurement capability will reject any dynamic signal of the junction's on voltage. The DA1855A's differential The DA1855A becomes a differential comparator when common to both sides of the junction, and the oscilloscope the internal PVG output is selected as the amplifier's is left to measure only the changes in the junction voltage. inverting (-) input. In this mode, the DA1855A can be used to measure relatively small signals that are riding on large AC or DC components (within the precision and accuracy Autobalance Each time either gain setting button is pressed, the DA1855A automatically adjusts the amplifier's DC balance. limitations of the PVG). Therefore, an oscilloscope, when used with the DA1855A, can make voltage measurements Specifications Ordering Information (cont'd) Main Specifications Bandwidth > 100 MHz Electrical Characteristics Rise time (typical) < 3.5 ns Ordering Information Product Description Product Code Differential Amplifiers 1 Ch, 100 MHz Differential Amplifier with Precision Voltage Source DA1855A /100 or /10 Selectable, 250 MHz Passive Differential Probe Pair DXC100A* /1, 50 MHz Passive Differential Probe Pair /100, 250 MHz 2.5kv, High Voltage Probe Pair (requires DA101 for full performance) DXC200* DXC-5100* 1-800-5-LeCroy teledynelecroy.com Product Description Product Code /10 1 M Passive Attenuator for DXC Series Probes 2 Ch,100 MHz Differential Amplifier with Precision Voltage Source DA101* DA1855A-PR2 DA1855A with Rackmount DA1855A with Rackmount (must be ordered at time of purchase, no retrofit) DA1855A-RM DA1855A-PR2-RM *Must be used with DA Series Differential Amplifiers Customer Service Teledyne LeCroy oscilloscopes and probes are designed, built, and tested to ensure high reliability. In the unlikely event you experience difficulties, our digital oscilloscopes are fully warranted for three years and our probes are warranted for one year. This warranty includes: * No charge for return shipping * Long-term 7-year support * Upgrade to latest software at no charge Local sales offices are located throughout the world. Visit our website to find the most convenient location. (c) 2018 by Teledyne LeCroy, Inc. All rights reserved. Specifications, prices, availability, and delivery subject to change without notice. Product or brand names are trademarks or requested trademarks of their respective holders. da1855a-ds-07feb18